Humic acid and enzymes inclusion in canola-based diets generate different responses in growth performance, protein utilization dynamics, and hemato-biochemical parameters in broiler chickens

Humic acid and enzymes inclusion in canola-based diets generate different responses in growth... Abstract The current study was conducted to investigate the effect of a humic acid and enzymes on growth performance, protein utilization, and blood parameters in broilers fed canola-based diets. Canola meal (CM) is characterized as low protein compared to soybean meal. Two-hundred-twenty broiler chickens were randomly allotted to the following 5 dietary treatments: 1. Control (commercial broiler diet); 2. CM (17.5% canola meal inclusion); 3. CMEnz (CM + 0.3 g/kg enzymes [Axtra XAP]); 4. CMPh (CM + 1.5% potassium humate, PH) and 5. CMEnzPh (CM + 1.5% PH + 0.3 g/kg Axtra XAP). Each treatment was replicated 4 times with each pen holding 11 birds as the experimental unit. The feeding trial was conducted over a grower (15 to 28 d) and a finisher phase (29 to 42 d). Diet did not affect (P > 0.05) feed intake across either grower or finisher phase but affected average daily gain (ADG) in the grower phase. In the grower phase, broilers fed CM had the highest ADG (71± 1.08 g/d), while the control (63.75 ± 1.08 g/d) had the lowest. However, control chickens had the highest feed conversion ratio (FCR) (1.65), while those fed CM (1.47) had the lowest. Diet significantly affected total white blood cell and white blood cell differential, which were consistently high in broilers fed CMEnzPh. With regard to serum metabolites, CM had the highest levels (P < 0.05) of aspartate aminotransferase (AST) (406.86 ± 38.07 IU/L), while CMEnzPh (254.17 ± 41.11 IU/L) had the lowest levels. Additionally, broilers fed CMPh had the highest (P < 0.05) serum sodium content (150.57 ± 0.69 mmol/l). Overall, canola meal, in the presence of enzymes and humic acid, was shown to have great potential as an alternative replacement of soybean meal in broiler diets. The findings from the study can, therefore, contribute to the design of low-cost canola-based feed formulations that will improve growth performance and health status in poultry farming systems in the future. INTRODUCTION Broiler rations are often formulated from maize grain, known to be an excellent energy source, and soybean meal (SBM), which has a balanced amino acid profile, thus providing high-quality protein for the birds (Opalinski et al., 2006). However, soybean is becoming expensive due to the need to meet both the human and animal demand for protein sources. Consequently, there is a need to explore other protein sources that can practically be included in broiler rations, allowing for least-cost ration formulation. Canola meal (CM) has been suggested as an alternative protein source (Wickramasuriya et al., 2015), despite its nutrient composition being relatively lower than that of SBM. In addition, the high fiber content in CM appears to offset the nutritional benefits that may be realized from using CM in chicken diets. The utilization of dietary ingredients such as canola that have high fiber levels and considerable amounts of some secondary plant metabolite (glucosinolates and sinapine) ingredients such as canola can be improved by the use of exogenous enzyme complexes such as Axtra XAP, an enhanced combination of xylanase, amylase, and protease, providing vital flexibility in poultry diet formulations. Xylanase has the ability to attack and disrupt cell wall material in canola, thus releasing encapsulated carbohydrates, including starch, free sugars, and soluble non-starch polysaccharides (NSP), while amylase may increase the digestion of the released carbohydrates (Fang et al., 2007). On the other hand, protease might break down a portion of protein that may escape digestion in the gut, ultimately increasing protein digestion efficiency (Mahmood et al., 2017). The use of exogenous enzymes in canola diets has the potential to increase digestibility, general health status, and performance of broilers (Angel et al., 2011). The use of exogenous enzymes as feed additives to improve utilization of poor nutrient sources can be complemented by inclusion of natural organic acids such as humates in place of conventional antibiotic growth promoters. The enzyme-humic acid combination may offer a potential alternative to the use of conventional antibiotic growth promoters, which have been implicated in the rise of antibiotic-resistant super bugs and residues in meat products. Worldwide, there has been a general belief that inclusion of organic acids, such as humic acids, as a feed additive in broiler diets can have multiple health and nutritional benefits (Ozturk et al., 2012; Ragaa and Korany, 2016). Organic acids have been observed to alter gut pH, concurrently enhancing peptic activities and increased N digestibility, resulting in higher feed conversion ratio (FCR) and average daily gain (ADG) in broiler chickens (Christian and Mellor, 2011; Dehghani-Taftia and Jahaniana, 2016; Ragaa and Korany, 2016). Additionally, organic acids such as humic acid have inhibition properties against acid-intolerant bacteria, including E. coli, Salmonella spp., and Clostridium perfringens, and hence can be used as alternatives to antibiotics (Fascina et al., 2012; Naseri, 2012). In spite of the great potential of CM, and inclusion of exogenous enzymes and humic acid as feed additives in formulations of low-cost diets, there is generally a lack of information on their simultaneous use in poultry production. Therefore, the objective of this study was to determine the influence of enzymes and potassium humate supplementation on growth performance and blood parameters of broilers fed canola-based diets. MATERIALS AND METHODS Study Site The study was conducted at the North-West University experimental farm (Molelwane). The study site is located in the North-West province of South Africa. The geographical coordinates are 25° 28΄ 0″ south, 22° 28΄ 0″ sast. The study area is ∼920 to 1,782 meters above sea level. Temperatures range from 3 to 37°C, and rainfall ranges between 300 and 500 mm annually. Feed Components The potassium humate was obtained from Nutrico (Kempton Park, SA), while a commercial enzyme complex Axtra XAP (xylanase, amylase, and protease) was obtained from Opti Feeds, Lichtenburg, SA. Canola meal, which is an oilcake derived from oil extraction, was obtained from Southern Oil (PTY) LTD, Western Cape, and all other dietary components were obtained from Opti Feeds, Lichtenburg, SA. Experimental Design A total of 220 day-old chicks (Cobb 500) obtained from Mimosa Chicks (Mafikeng, SA) was randomly allotted to 5 dietary treatments replicated 4 times with a pen housing 11 birds as the experimental unit. The study was arranged in a completely randomized design. The pens (measuring 3.5 × 1.0 × 1.85 m) were designed to meet the animal welfare standards for optimum production of broilers. Dietary Treatments The control diet was composed of a commercial diet whose protein sources were SBM prime gluten and full-fat soya, while the other 4 diets contained CM at 17.5% inclusion in place of SBM. The 5 dietary treatments were formulated as follows: 1. Control (commercial broiler diet); 2. CM (17.5% CM inclusion); 3. CMEnz (CM + 0.3 g/kg Axtra XAP); 4. CMPh (CM + 1.5% potassium humate, PH), and 5. CMEnzPh (CM + 1.5% PH + 0.3 g/kg Axtra XAP). The 17.5% canola inclusion was the maximum rate allowable for formulation of a balanced broiler diet, while the inclusion level of enzymes was the recommended level provided by feed companies for ingredients such as CM with a lower protein source containing high fiber. The inclusion level of PH was derived based on the ranges from literature (Ozturk et al., 2012; Ragaa and Korany, 2016). Chemical composition of soya bean meal and CM are shown in Table 1, while Table 2 and Table 3 show the ingredients, dietary formulations, and nutritional compositions of the diets. Near-infrared reflectance spectroscopy (NIRS) was used to determine the proximate composition of the ingredients and diets. Table 1. Chemical composition of soya bean meal and canola meal. Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 ADF = acid detergent fiber; NDF = neutral detergent fiber; RUP = rumen undegradable protein; P = phosphorus; Mg = Magnesium; K = potassium; Cl = chlorine; Na = sodium; S = sulfur. View Large Table 1. Chemical composition of soya bean meal and canola meal. Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 ADF = acid detergent fiber; NDF = neutral detergent fiber; RUP = rumen undegradable protein; P = phosphorus; Mg = Magnesium; K = potassium; Cl = chlorine; Na = sodium; S = sulfur. View Large Table 2 Ingredients composition of experimental diets for grower and finisher broilers. Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 1Dietary treatments: Control = commercial broiler diet; CM = commercial broiler diet in which 17.5% of SBM was replaced by canola meal; CMEnz = CM diet + 0.3 g/kg Axtra XAP enzyme complex; CMPh = CM diet + 1.5% potassium humate; and CMEnzPh = CM diet + 1.5% PH + 0.3 g/kg Axtra XAP enzymes. View Large Table 2 Ingredients composition of experimental diets for grower and finisher broilers. Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 1Dietary treatments: Control = commercial broiler diet; CM = commercial broiler diet in which 17.5% of SBM was replaced by canola meal; CMEnz = CM diet + 0.3 g/kg Axtra XAP enzyme complex; CMPh = CM diet + 1.5% potassium humate; and CMEnzPh = CM diet + 1.5% PH + 0.3 g/kg Axtra XAP enzymes. View Large Table 3 Nutrient composition (%) of experimental diets for grower and finisher broilers determined by NIRS.1 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 1Near-infrared spectroscopy (NIRS) is a rapid, non-destructive analytical method that uses reflectance and transmittance to determine chemical composition of feedstuffs, ingredients, and other raw materials, with a high degree of accuracy and precision that are comparable to primary reference methods. The recorded NIR spectra contain a variety of chemical and physical (e.g., particle size) information on the sample and its constituents, which represent the chemical composition of the diets and ingredients. 2ME: Metabolizable energy. View Large Table 3 Nutrient composition (%) of experimental diets for grower and finisher broilers determined by NIRS.1 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 1Near-infrared spectroscopy (NIRS) is a rapid, non-destructive analytical method that uses reflectance and transmittance to determine chemical composition of feedstuffs, ingredients, and other raw materials, with a high degree of accuracy and precision that are comparable to primary reference methods. The recorded NIR spectra contain a variety of chemical and physical (e.g., particle size) information on the sample and its constituents, which represent the chemical composition of the diets and ingredients. 2ME: Metabolizable energy. View Large Animal Management On the d of arrival, the chicks were placed in pens measuring 3.5 × 1.0 × 1.85 m in a broiler house. During the first 3 d of brooding, the ambient temperature in the house was kept between 32.5 and 33°C but was gradually reduced reaching 26°C at 14 d of age. These temperature requirements were met using infrared lights that were used until d 14. Stress packs that contained antioxidants (B-vitamins, vitamin K, vitamin A, vitamin C, and choline) were given to the chicks for 3 days. The birds were phase-fed starting with the provision of starter ration from d 1 to 14. Experimental diets were offered only during the grower (d 15 to 28) and finisher (d 29 to 42) phases. Water was provided ad libitum. Experimental diets were formulated according to the commercial feed formulation standards to meet the nutrient requirements for the grower and finisher phases (NRC, 1994). The experimental procedures were approved by the MAREC Animal Research Ethics Committee of North-West University, and the Ethics number granted is NWU-00516–16-S9. No mortalities were recorded over the period of study. Feed Intake and Growth Performance Feed intake was measured daily and weight gain was measured weekly. All birds from the 20 pens were weighed at the beginning of the trial on d 14 (initial body weight, 360.17 ± 9.12 g) and subsequently weighed weekly (21, 28, 35, and 42 d) using TSW equipment weighing scales/Adam equipment, SA, to obtain the cumulative weight gain (CWG). The feed offered was weighed before feeding and refusals were collected each morning before feeding and weighed. The average daily feed intake (ADFI), ADG, and FCR for each feeding phase were calculated as: \begin{eqnarray} {\rm{ADFI}} = \frac{{{{\it Feed\ offered - feed\ refused}}}}{{\it 14\ days}} \end{eqnarray} (1) \begin{eqnarray} {\rm{ADG}} = \frac{{\it Finish\ weight - Start\ weight\ }}{{\it Age \left({days} \right)}} \end{eqnarray} (2) \begin{eqnarray} {\rm{FCR}} = \frac{{\it feed\ intake\ \left( g \right)}}{{\it weight\ gain\ \left( g \right)}} \end{eqnarray} (3) Protein Utilization Efficiency Protein consumed (PC g/bird) was calculated by multiplying the concentration of crude protein (CPd) in the diet (g/kg DM consumed) by feed intake over the feeding phase, while protein efficiency ratio (PER g/kg) was calculated by dividing mean body weight gain (BWG) by the mean protein consumed. Specific growth rate (SGR), which is percent growth per feeding phase and growth efficiency (GE), also were calculated using the following formulas: \begin{eqnarray}{\rm{PC}} &=& {\it FI}\ \times {\it CPd}\end{eqnarray} (4) \begin{eqnarray}{\rm{PER}} &=& \frac{{\ BWG\ }}{{PC\ }}\end{eqnarray} (5) \begin{eqnarray} { {\rm{SGR}}}\nonumber\\ = \frac{{\left( {\it{In\ final\ weight\ - \ In\ initial\ weight}} \right)\ }}{{\it 14\ d\ }} \times \ 100\nonumber\\ \end{eqnarray} (6) \begin{eqnarray}{\rm{GE}} = \frac{{\ BWG\ }}{{\it{Initial\ weight} }}\end{eqnarray} (7) Blood Collection and Analysis From each pen, 2 broilers were chosen randomly for blood collection at 40 d of age. Blood was collected from the brachial vein using needle and syringe, and then transferred into 2 types of tubes. The blood samples were taken to Lancet laboratory (Mafikeng, SA) within 2 h of collection for blood analysis. An anti-coagulant was used for hematological analyses using a purple tube so that the blood does not clot. The Idexx lasercyte (hematology analyser) was used to analyze for hematocrit, hemoglobin, erythrocyte, leucocyte, neutrophils, lymphocytes, monocytes, eosinophil, and normoblasts. For serum biochemical indices, the tube without anticoagulant for serum (red tube) was used. The enzymes were analyzed using a clinical chemistry analyzer (Gilford Impact, 404lE, Ciba Coming Diagnostic Corp., Gilford Systems, Oberlin, OH). A UV–VIS spectrophotometer (SPECORD 50 PC, Analytik Jena AG) was used to perform the enzyme assays using respective commercial kits (Ciba Coming Diagnostic Corp., Gilford Systems, Oberlin, OH). The total protein (TP) and albumin, cholesterol, and mineral content were quantified using an auto-analyzer (Hitachi-704, Boehringer Mannheim Ltd, Germany). Statistical Analysis Data on growth, protein utilization efficiency, hematology and serum biochemistry parameters measured were analyzed using the GLM procedure of SAS (2010) with diet as the only fixed effect (model 1). Data on cumulative weight gain were measured on a weekly basis and were analyzed using the mixed model procedure of SAS (2010), which took into consideration the effect of both diet and wk of measurement (model 2) with diet as a fixed factor. The probability differences (PDIFF) option of SAS (2010) was used to perform pairwise comparisons of the least square means, while contrasts (SAS, 2010) were used to determine the specific effects of enzyme, organic acid, and their interaction on different parameters. The statistical models were as follows: \begin{eqnarray}{Y_{ij}} = {\rm{ }}\mu {\rm{ }} + {\rm{ }}{T_i} + {\rm{ }}{\varepsilon _{ij}}\end{eqnarray} (model 1) Where: Yij = observation (growth parameters and blood parameter), μ = population mean constant common to all observations, Ti = effect of diet, and εij = random error term. \begin{eqnarray}{Y_{ijk}} = {\rm{ }}\mu {\rm{ }} + {\rm{ }}{T_i} + {\rm{ }}{W_j} + {\rm{ }}{\left( {T{\rm{ }}*{\rm{ }}W} \right)_{ij}} + {\rm{ }}{\varepsilon _{ijk}}\nonumber \\\end{eqnarray} (model 2) Where: Yij = observation (cumulative weight gain parameter), μ = population mean constant common to the observation, Ti = effect of diet, T * Wij = effect of diet interacting with wk, and εij = random error term. For all tests, the level of significance was set at (P < 0.05). RESULTS Growth Performance The effects of humic acid and enzymes inclusion in canola diets on growth parameters of broilers at different feeding phases are presented in Table 4. Diet had no influence on ADFI in either grower or finisher phase. Similarly, dietary treatment had no effect on ADG or FCR of the broilers in the finisher feeding phase. On the contrary, significant (P < 0.05) differences in ADG and FCR of broilers in the grower phase were observed. In the grower phase, broiler chickens fed the CM diet had higher (P < 0.05) ADG (71 ± 1.08 g/d), while those in the control had the lowest (63.75 ± 1.81 g/d). In contrast, broilers in the control (1.65 ± 0.04) had the lowest (P < 0.05) FCR, while those in CM had the lowest (1.47 ± 0.04). No differences were observed in growth parameters in the finisher phase. Overall, the CMEnzPh fed broilers had higher ADG (P < 0.05) compared with those fed the control diet. However, no differences were observed in ADG between the control group and the CMEnz and CMPh treatment groups. In addition, no differences were observed in overall FCR between the control group and the CMEnz, CMPh, and CMEnzPh treatment groups. Table 4 Effect of enzyme complex and humic acid inclusion on growth performance of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ADFI = average daily feed intake; ADG = average daily gain; FCR = feed conversion ratio. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 4 Effect of enzyme complex and humic acid inclusion on growth performance of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ADFI = average daily feed intake; ADG = average daily gain; FCR = feed conversion ratio. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large The CWG of broilers over the experimental period is presented in Figure 1. A clear linear increase in weight gain was observed in both the grower and finisher feeding phases for all the diets except CM. The CWG of the control appeared to be depressed between wk 2 and 3, although it increased sharply thereafter. Among all treatments, the control had the lowest CWG (333.8 g/wk) compared to all the other treatments. No differences in CWG were observed for broilers fed CM or CMEnzPh. Nevertheless, broilers in CMEnzPh had the highest values of CWG throughout the feeding period. Broilers fed CM had the lowest final weight (2130.9 g), while those fed CMEnzPh had the highest (2254.4 g). Figure 1. View largeDownload slide Effect of potassium humate and Axtra XAP on cumulative weight gain on broiler chickens fed canola-based diets. Figure 1. View largeDownload slide Effect of potassium humate and Axtra XAP on cumulative weight gain on broiler chickens fed canola-based diets. Protein Utilization and Growth Efficiency The results of protein utilization and growth efficiency are presented in Table 5. Dietary treatment significantly (P < 0.05) affected protein utilization and growth efficiency parameters in both grower and finisher phases except for PC in the finisher phase. In the grower phase, PC was higher in CMEnzPh (20.12 g) and CMEnz compared with the control. However, CM and CMPh had the highest (P < 0.05) PER, while the control had the lowest. Specific growth rate was higher in CM than all other treatments. In all instances, the control had the lowest values for PER, SGR, and GE in the grower phase. On the contrary, in the finisher phase, although the control had the lowest value for PC, the values for PER, SGR, and GE were higher (P < 0.05) than all other treatments. Table 5. Effect of enzyme complex and humic acid inclusion on protein utilization efficiency of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 a,bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PC = protein consumed, PER = protein efficiency ratio, SGR = specific growth rate, GE = growth efficiency. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 5. Effect of enzyme complex and humic acid inclusion on protein utilization efficiency of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 a,bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PC = protein consumed, PER = protein efficiency ratio, SGR = specific growth rate, GE = growth efficiency. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Hematology Parameters The full blood parameters are presented in Table 6. As illustrated in the table, treatment had no effect on packed cell volume (PCV), hemoglobin (Hb), or the total red blood cell (RBC) count. However, diets affected (P < 0.05) total white blood cell counts (WBC) and all WBC differential counts. Interestingly, broilers fed CMEnz had the lowest amount of the WBC differential counts, while broilers fed CMEnzPh consistently had the highest (P < 0.05) counts. The neutrophil to WBC, lymphocytes to WBC, and neutrophil to lymphocytes ratios were not (P > 0.05) affected by the diet. Table 6. Effect of enzyme complex and humic acid inclusion on hematology of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PCV = packed cell volume, WBC = white blood cell, Neutro = neutrophils, and Lym = lymphocytes. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 6. Effect of enzyme complex and humic acid inclusion on hematology of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PCV = packed cell volume, WBC = white blood cell, Neutro = neutrophils, and Lym = lymphocytes. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Serum Biochemical Parameters The serum biochemical indices presented in Table 7 show no dietary effect on liver enzymes or blood minerals apart from AST and sodium. Chickens offered the CM diet (406.86 ± 38.07 IU/L) had the highest levels (P < 0.05) of AST followed by CMEnz chickens (389.86 ± 38.07 IU/L). The CMEnzPh chickens had the lowest AST levels (254.17 ± 41.11 IU/L). The diet also affected the serum concentrations of sodium with CMPh chickens (150.57 ± 0.69 mmol/l) having the highest (P < 0.05) sodium content compared to the control, CM, and CMEnzPh (147.44, 147.14, and 147.16 mmol/l, respectively) chickens. Diet had no effect on total protein, serum albumin, cholesterol, or any other minerals. Table 7 Effect of enzyme complex and humic acid inclusion on serum biochemistry parameters in broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ALP = alanine aminotransferase, ALT = alkaline phosphatase and AST = aspartate aminotransferase; 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 7 Effect of enzyme complex and humic acid inclusion on serum biochemistry parameters in broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ALP = alanine aminotransferase, ALT = alkaline phosphatase and AST = aspartate aminotransferase; 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large DISCUSSION The lack of dietary treatment effects on the ADFI for both grower and finisher phases suggests that canola inclusion level (17.5%) was within the optimal range and, therefore, did not cause any significant changes in physico-chemical properties of the diets. Generally, raw ingredients used in the formulation of diets have an influence on physico-chemical properties of the diets that may affect the taste, palatability, and functional properties of the diets, ultimately altering feed intake in broilers. The lack of dietary treatment effects on the ADFI also could be explained by the fact that the broilers, at the grower stage, have a fully developed digestive system to cope with the higher fiber and secondary plant metabolites, particularly glucosinolates, which characterize the CM (Mailer et al., 2008). The CM used in the current study had high fiber (12%) and lower protein (36 to 39%) compared to SBM. It also contained considerable amounts of glucosinolates (3.8 μmol/g), but these were not significant enough to affect the performance of the birds. The high fiber content in canola could therefore have reduced feed intake, resulting in lower BWG of broiler chickens (Widyaratne and Drew, 2011). However, ADG was higher in canola-containing diets, while FCR also was improved. The higher ADG and reduced FCR in canola-containing treatments could be attributed to humic acid and enzymes, which may have improved the feed efficiency given the reduced feed intake. Growth promoting agents such as humic acid and exogenous enzymes have been observed to improve digestion and feed utilization dynamics of poor protein sources (Ferket and Gernat, 2006; Rath et al., 2006; Toghyani et al., 2010). The results of the current study from both feeding phases indicated that feeding enzymes improved feed utilization of canola-based diets, as was observed in other studies (Pucci et al, 2010; Tang et al. 2014). Cowieson and Ravindran (2008) also observed that addition of enzymes in broiler diets had a positive influence on the overall performance of broilers. However, Kocher et al. (2003) observed that an enzymes-only diet had a slight influence on overall performance of broilers. In addition, other researchers observed that addition of an enzyme complex had a negative influence on performance variables (Brufau et al., 2006; Yegani and Korver, 2013). Nevertheless, the positive effects observed in the current study indicate that Axtra XAP was effective in the breakdown of the matrix of cell walls in fibrous canola, thus helping the release of nutrients captured in cell walls due to easier access of digestive enzymes to these substrates, as observed in other studies (Fang et al., 2007; Christian and Mellor, 2011; Dehghani-Taftia and Jahaniana, 2016; Ragaa and Korany, 2016). The high PER observed in the CMPh and CMEnzPh compared to the control diet could be due to the effects of humic acids in enhancing peptic activities and increasing N digestibility through alteration of gut pH (Christian and Mellor, 2011; Ragaa and Korany, 2016). Overall, hematological indices were observed to be within the anticipated ranges for healthy broilers (Merck Manual, 2012). This implies that the inclusion of CM and the growth-promoting agents did not influence hematopoiesis. In fact, the desirable blood metabolite levels realized in the current study indicates the potential of the humic acid and CM in improving the general health status of broilers. In other studies, compounds of a similar nature were observed to reduce the hematological disorders associated with aflatoxins and mycotoxins in feeds (Abdel-Wahhab and Aly, 2005; Ozturk et al., 2012). Generally, hematological indices are normally indicative of the health status of animals. In the current study, no effect of diet was observed on the lymphocyte to WBC, neutrophil to WBC, or neutrophil to lymphocyte ratios. The WBC ratios could be used as reliable biomarkers that indicate any inflammations stimulated by feed-induced stress. Currently, information on the use of such ratios in assessing the effects of unconventional dietary additives on the general health of broilers is largely unavailable. The serum metabolites observed were all within normal ranges for healthy broiler chickens (Merck Manual, 2012). Serum biochemical indices normally reflect the condition of an animal and any changes in response to internal and exogenous factors (Toghyani et al., 2010). Measuring these parameters is significant for monitoring the general health and nutritional status of broilers. Although AST levels were higher for the birds fed canola diets, the levels were still within the normal ranges. Nevertheless, the observed high levels of AST in CM and CMEnz could perhaps be due to an increased liver activity in an attempt to detoxify the higher amounts of secondary plant metabolites in canola. Generally, higher levels of liver enzyme above the normal ranges signify liver damage (hepatocellular degeneration; Badari et al., 2003). This also may be manifested in reduced blood flow (ischemia) to the liver (Khajali and Slominski, 2012). Interestingly, the AST values in chickens offered potassium humate-containing diets were similar to those of the chickens fed the control diet. This may be indicative of the hepato-protective abilities of potassium humate in reducing free radicals induced by increased amounts of secondary plant metabolites in canola, which could have caused liver damage (Hern´andez et al., 2006). As observed in other studies, no variation in protein concentration or total albumin was observed in the current study. Together with other serum metabolites, protein concentration gives an indication of the adequacy of protein in the diet and the efficiency with which it is being utilized by the broilers (Ghammry et al., 2002). The results, therefore, imply that the inclusion of canola in diets did not impede protein digestion or utilization by broiler chickens. In conclusion, our results showed that inclusion of humic acid and enzymes in canola-based diet positively influenced growth performance and health status of broilers fed canola-based diets. Growth performance indices of broilers fed supplemented canola-based diets were improved due to the growth-promoting effects of humic acid and enzymes, which resulted in improved feed utilization efficiency. The low AST levels in chickens fed diets containing humic acid indicates the hepato-protective ability of humic acid. Overall, CM was shown to have great potential as an alternative replacement of SBM in broiler diets. Collectively, findings from the study can be helpful in designing low-cost feed formulations that will improve growth performance and health status in poultry farming systems in the future. Nevertheless, it also may be interesting to investigate whether the influence of humic acid and enzyme inclusion in diets may be associated with an improvement on meat quality attributes of broiler meat. Acknowledgements We thank the National Research Foundation (NRF) and the Health and Welfare Sector Education and Training Authority (HWSETA) for providing the research funds and NUTRICO (Pvt, Ltd) for providing the potassium humate. REFERENCES Abdel-Wahhab M. A. , Aly S. E. . 2005 . Antioxidant property of Nigella sativa (black cumion) and Syzygium aromaticum (colve) in rats during of latoxicosis . J. Appl. Toxicol . 25 : 218 – 223 . Google Scholar CrossRef Search ADS PubMed Angel C. R. , Saylor W. , Vieira S. L. , Ward N. . 2011 . 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Humic acid and enzymes inclusion in canola-based diets generate different responses in growth performance, protein utilization dynamics, and hemato-biochemical parameters in broiler chickens

Poultry Science , Volume Advance Article (8) – Jul 11, 2018

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Oxford University Press
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© 2018 Poultry Science Association Inc.
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0032-5791
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1525-3171
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10.3382/ps/pey047
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Abstract

Abstract The current study was conducted to investigate the effect of a humic acid and enzymes on growth performance, protein utilization, and blood parameters in broilers fed canola-based diets. Canola meal (CM) is characterized as low protein compared to soybean meal. Two-hundred-twenty broiler chickens were randomly allotted to the following 5 dietary treatments: 1. Control (commercial broiler diet); 2. CM (17.5% canola meal inclusion); 3. CMEnz (CM + 0.3 g/kg enzymes [Axtra XAP]); 4. CMPh (CM + 1.5% potassium humate, PH) and 5. CMEnzPh (CM + 1.5% PH + 0.3 g/kg Axtra XAP). Each treatment was replicated 4 times with each pen holding 11 birds as the experimental unit. The feeding trial was conducted over a grower (15 to 28 d) and a finisher phase (29 to 42 d). Diet did not affect (P > 0.05) feed intake across either grower or finisher phase but affected average daily gain (ADG) in the grower phase. In the grower phase, broilers fed CM had the highest ADG (71± 1.08 g/d), while the control (63.75 ± 1.08 g/d) had the lowest. However, control chickens had the highest feed conversion ratio (FCR) (1.65), while those fed CM (1.47) had the lowest. Diet significantly affected total white blood cell and white blood cell differential, which were consistently high in broilers fed CMEnzPh. With regard to serum metabolites, CM had the highest levels (P < 0.05) of aspartate aminotransferase (AST) (406.86 ± 38.07 IU/L), while CMEnzPh (254.17 ± 41.11 IU/L) had the lowest levels. Additionally, broilers fed CMPh had the highest (P < 0.05) serum sodium content (150.57 ± 0.69 mmol/l). Overall, canola meal, in the presence of enzymes and humic acid, was shown to have great potential as an alternative replacement of soybean meal in broiler diets. The findings from the study can, therefore, contribute to the design of low-cost canola-based feed formulations that will improve growth performance and health status in poultry farming systems in the future. INTRODUCTION Broiler rations are often formulated from maize grain, known to be an excellent energy source, and soybean meal (SBM), which has a balanced amino acid profile, thus providing high-quality protein for the birds (Opalinski et al., 2006). However, soybean is becoming expensive due to the need to meet both the human and animal demand for protein sources. Consequently, there is a need to explore other protein sources that can practically be included in broiler rations, allowing for least-cost ration formulation. Canola meal (CM) has been suggested as an alternative protein source (Wickramasuriya et al., 2015), despite its nutrient composition being relatively lower than that of SBM. In addition, the high fiber content in CM appears to offset the nutritional benefits that may be realized from using CM in chicken diets. The utilization of dietary ingredients such as canola that have high fiber levels and considerable amounts of some secondary plant metabolite (glucosinolates and sinapine) ingredients such as canola can be improved by the use of exogenous enzyme complexes such as Axtra XAP, an enhanced combination of xylanase, amylase, and protease, providing vital flexibility in poultry diet formulations. Xylanase has the ability to attack and disrupt cell wall material in canola, thus releasing encapsulated carbohydrates, including starch, free sugars, and soluble non-starch polysaccharides (NSP), while amylase may increase the digestion of the released carbohydrates (Fang et al., 2007). On the other hand, protease might break down a portion of protein that may escape digestion in the gut, ultimately increasing protein digestion efficiency (Mahmood et al., 2017). The use of exogenous enzymes in canola diets has the potential to increase digestibility, general health status, and performance of broilers (Angel et al., 2011). The use of exogenous enzymes as feed additives to improve utilization of poor nutrient sources can be complemented by inclusion of natural organic acids such as humates in place of conventional antibiotic growth promoters. The enzyme-humic acid combination may offer a potential alternative to the use of conventional antibiotic growth promoters, which have been implicated in the rise of antibiotic-resistant super bugs and residues in meat products. Worldwide, there has been a general belief that inclusion of organic acids, such as humic acids, as a feed additive in broiler diets can have multiple health and nutritional benefits (Ozturk et al., 2012; Ragaa and Korany, 2016). Organic acids have been observed to alter gut pH, concurrently enhancing peptic activities and increased N digestibility, resulting in higher feed conversion ratio (FCR) and average daily gain (ADG) in broiler chickens (Christian and Mellor, 2011; Dehghani-Taftia and Jahaniana, 2016; Ragaa and Korany, 2016). Additionally, organic acids such as humic acid have inhibition properties against acid-intolerant bacteria, including E. coli, Salmonella spp., and Clostridium perfringens, and hence can be used as alternatives to antibiotics (Fascina et al., 2012; Naseri, 2012). In spite of the great potential of CM, and inclusion of exogenous enzymes and humic acid as feed additives in formulations of low-cost diets, there is generally a lack of information on their simultaneous use in poultry production. Therefore, the objective of this study was to determine the influence of enzymes and potassium humate supplementation on growth performance and blood parameters of broilers fed canola-based diets. MATERIALS AND METHODS Study Site The study was conducted at the North-West University experimental farm (Molelwane). The study site is located in the North-West province of South Africa. The geographical coordinates are 25° 28΄ 0″ south, 22° 28΄ 0″ sast. The study area is ∼920 to 1,782 meters above sea level. Temperatures range from 3 to 37°C, and rainfall ranges between 300 and 500 mm annually. Feed Components The potassium humate was obtained from Nutrico (Kempton Park, SA), while a commercial enzyme complex Axtra XAP (xylanase, amylase, and protease) was obtained from Opti Feeds, Lichtenburg, SA. Canola meal, which is an oilcake derived from oil extraction, was obtained from Southern Oil (PTY) LTD, Western Cape, and all other dietary components were obtained from Opti Feeds, Lichtenburg, SA. Experimental Design A total of 220 day-old chicks (Cobb 500) obtained from Mimosa Chicks (Mafikeng, SA) was randomly allotted to 5 dietary treatments replicated 4 times with a pen housing 11 birds as the experimental unit. The study was arranged in a completely randomized design. The pens (measuring 3.5 × 1.0 × 1.85 m) were designed to meet the animal welfare standards for optimum production of broilers. Dietary Treatments The control diet was composed of a commercial diet whose protein sources were SBM prime gluten and full-fat soya, while the other 4 diets contained CM at 17.5% inclusion in place of SBM. The 5 dietary treatments were formulated as follows: 1. Control (commercial broiler diet); 2. CM (17.5% CM inclusion); 3. CMEnz (CM + 0.3 g/kg Axtra XAP); 4. CMPh (CM + 1.5% potassium humate, PH), and 5. CMEnzPh (CM + 1.5% PH + 0.3 g/kg Axtra XAP). The 17.5% canola inclusion was the maximum rate allowable for formulation of a balanced broiler diet, while the inclusion level of enzymes was the recommended level provided by feed companies for ingredients such as CM with a lower protein source containing high fiber. The inclusion level of PH was derived based on the ranges from literature (Ozturk et al., 2012; Ragaa and Korany, 2016). Chemical composition of soya bean meal and CM are shown in Table 1, while Table 2 and Table 3 show the ingredients, dietary formulations, and nutritional compositions of the diets. Near-infrared reflectance spectroscopy (NIRS) was used to determine the proximate composition of the ingredients and diets. Table 1. Chemical composition of soya bean meal and canola meal. Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 ADF = acid detergent fiber; NDF = neutral detergent fiber; RUP = rumen undegradable protein; P = phosphorus; Mg = Magnesium; K = potassium; Cl = chlorine; Na = sodium; S = sulfur. View Large Table 1. Chemical composition of soya bean meal and canola meal. Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 Components (%) Soya bean meal Canola meal Crude protein (%) 47.0 36.26 Ether extract (%) 2.0 2.94 Ash (%) 7.0 7.16 NDF (%) 8.5 23.28 ADF (%) 6.5 16.19 Crude fiber (%) 3.72 10.36 RUP (%) 14.1 10.88 Calcium (%) 0.29 0.67 P (%) 0.68 1.15 Mg (%) 0.27 0.53 K (%) 2.0 1.25 Cl (%) 0.01 0.1 Na (%) 0.007 0.08 S (%) 0.4 0.64 Glucosinolates (μmol/g) 0 3.8 ADF = acid detergent fiber; NDF = neutral detergent fiber; RUP = rumen undegradable protein; P = phosphorus; Mg = Magnesium; K = potassium; Cl = chlorine; Na = sodium; S = sulfur. View Large Table 2 Ingredients composition of experimental diets for grower and finisher broilers. Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 1Dietary treatments: Control = commercial broiler diet; CM = commercial broiler diet in which 17.5% of SBM was replaced by canola meal; CMEnz = CM diet + 0.3 g/kg Axtra XAP enzyme complex; CMPh = CM diet + 1.5% potassium humate; and CMEnzPh = CM diet + 1.5% PH + 0.3 g/kg Axtra XAP enzymes. View Large Table 2 Ingredients composition of experimental diets for grower and finisher broilers. Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 Dietary treatments1 Grower Finisher Ingredients Control CM CMEnz CMPh CMEnzPh Control CM CMEnz CMPh CMEnzPh Yellow maize-fine 69.90 59.50 59.50 59.5 59.50 76.20 66.40 66.40 66.40 66.40 Canola oilcake (HEX) 0.00 17.50 17.50 17.5 17.50 0.00 17.50 17.50 17.50 17.50 Prime gluten 60 (yellow) 1.80 2.40 2.40 2.4 2.40 1.27 1.80 1.80 1.80 1.80 Full-fat soya 5.10 5.10 5.10 5.1 5.10 1.53 1.61 1.60 1.59 1.54 Soybean meal (local) 19.70 2.22 2.21 2.22 2.22 18.00 0.50 0.60 0.5 0.5 Limestone powder-fine 1.45 1.22 1.22 1.22 1.22 1.30 1.07 1.07 1.07 1.07 MCP/mono cal KK 0.72 0.56 0.56 0.56 0.56 0.50 0.33 0.33 0.33 0.33 Salt-fine 0.32 0.32 0.32 0.32 0.32 0.33 0.33 0.33 0.33 0.33 Koek soda 0.17 0.16 0.16 0.16 0.16 0.13 0.12 0.12 0.12 0.12 Choline powder 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 Lysine 0.28 0.29 0.29 0.29 0.29 0.26 0.27 0.27 0.27 0.27 L-Threonine 0.04 0.00 0.00 0 0.00 0.03 0.00 0.00 0.00 0.00 Methionine 0.19 0.18 0.18 0.18 0.18 0.16 0.09 0.09 0.09 0.09 PX P2 Br Gr with phytase 0.17 0.17 0.17 0.17 0.17 0.00 0.00 0.00 0.00 0.00 PX P3 Br Fin with phytase 0.00 0.00 0 0 0.00 0.17 0.17 0.17 0.17 0.17 Coxistac 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Olaquindox 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 Axtra XAP (g/kg) 0.00 0.00 0.30 0.00 0.30 0.00 0.00 0.30 0.00 0.3 Potassium humate (%) 0.00 0.00 0.00 1.50 1.50 0.00 0.00 0.00 1.50 1.50 1Dietary treatments: Control = commercial broiler diet; CM = commercial broiler diet in which 17.5% of SBM was replaced by canola meal; CMEnz = CM diet + 0.3 g/kg Axtra XAP enzyme complex; CMPh = CM diet + 1.5% potassium humate; and CMEnzPh = CM diet + 1.5% PH + 0.3 g/kg Axtra XAP enzymes. View Large Table 3 Nutrient composition (%) of experimental diets for grower and finisher broilers determined by NIRS.1 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 1Near-infrared spectroscopy (NIRS) is a rapid, non-destructive analytical method that uses reflectance and transmittance to determine chemical composition of feedstuffs, ingredients, and other raw materials, with a high degree of accuracy and precision that are comparable to primary reference methods. The recorded NIR spectra contain a variety of chemical and physical (e.g., particle size) information on the sample and its constituents, which represent the chemical composition of the diets and ingredients. 2ME: Metabolizable energy. View Large Table 3 Nutrient composition (%) of experimental diets for grower and finisher broilers determined by NIRS.1 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 Standard broiler diet composition Canola oil cake diet composition Parameters Grower Finisher Grower Finisher Volume 100 100 100 100 Moisture 10.93543 11.27404 11.345062 11.579352 ME2 11.79982 11.91972 12.099266 12.29989 Protein 18.93943 16.89748 18.800643 16.905623 Fat 6.244323 6.389549 5.961664 5.998489 Fiber 4.175833 4.027193 4.314995 4.205758 Ash 4.845047 4.254113 4.815068 4.218272 Linoleic 2.970173 2.527973 2.963169 2.550331 Choline 1285.453 1159.593 1283.75833 1173.79636 Calcium 0.850021 0.750026 0.850056 0.750005 Phosphorus 0.562513 0.501338 0.596865 0.495018 Sodium 0.180022 0.169984 0.179983 0.170003 Chlorine 0.3 0.299997 0.299991 0.3 Potassium 0.732957 0.655133 0.76275 0.684109 Arginine 1.10153 0.959095 1.100416 0.957639 1Near-infrared spectroscopy (NIRS) is a rapid, non-destructive analytical method that uses reflectance and transmittance to determine chemical composition of feedstuffs, ingredients, and other raw materials, with a high degree of accuracy and precision that are comparable to primary reference methods. The recorded NIR spectra contain a variety of chemical and physical (e.g., particle size) information on the sample and its constituents, which represent the chemical composition of the diets and ingredients. 2ME: Metabolizable energy. View Large Animal Management On the d of arrival, the chicks were placed in pens measuring 3.5 × 1.0 × 1.85 m in a broiler house. During the first 3 d of brooding, the ambient temperature in the house was kept between 32.5 and 33°C but was gradually reduced reaching 26°C at 14 d of age. These temperature requirements were met using infrared lights that were used until d 14. Stress packs that contained antioxidants (B-vitamins, vitamin K, vitamin A, vitamin C, and choline) were given to the chicks for 3 days. The birds were phase-fed starting with the provision of starter ration from d 1 to 14. Experimental diets were offered only during the grower (d 15 to 28) and finisher (d 29 to 42) phases. Water was provided ad libitum. Experimental diets were formulated according to the commercial feed formulation standards to meet the nutrient requirements for the grower and finisher phases (NRC, 1994). The experimental procedures were approved by the MAREC Animal Research Ethics Committee of North-West University, and the Ethics number granted is NWU-00516–16-S9. No mortalities were recorded over the period of study. Feed Intake and Growth Performance Feed intake was measured daily and weight gain was measured weekly. All birds from the 20 pens were weighed at the beginning of the trial on d 14 (initial body weight, 360.17 ± 9.12 g) and subsequently weighed weekly (21, 28, 35, and 42 d) using TSW equipment weighing scales/Adam equipment, SA, to obtain the cumulative weight gain (CWG). The feed offered was weighed before feeding and refusals were collected each morning before feeding and weighed. The average daily feed intake (ADFI), ADG, and FCR for each feeding phase were calculated as: \begin{eqnarray} {\rm{ADFI}} = \frac{{{{\it Feed\ offered - feed\ refused}}}}{{\it 14\ days}} \end{eqnarray} (1) \begin{eqnarray} {\rm{ADG}} = \frac{{\it Finish\ weight - Start\ weight\ }}{{\it Age \left({days} \right)}} \end{eqnarray} (2) \begin{eqnarray} {\rm{FCR}} = \frac{{\it feed\ intake\ \left( g \right)}}{{\it weight\ gain\ \left( g \right)}} \end{eqnarray} (3) Protein Utilization Efficiency Protein consumed (PC g/bird) was calculated by multiplying the concentration of crude protein (CPd) in the diet (g/kg DM consumed) by feed intake over the feeding phase, while protein efficiency ratio (PER g/kg) was calculated by dividing mean body weight gain (BWG) by the mean protein consumed. Specific growth rate (SGR), which is percent growth per feeding phase and growth efficiency (GE), also were calculated using the following formulas: \begin{eqnarray}{\rm{PC}} &=& {\it FI}\ \times {\it CPd}\end{eqnarray} (4) \begin{eqnarray}{\rm{PER}} &=& \frac{{\ BWG\ }}{{PC\ }}\end{eqnarray} (5) \begin{eqnarray} { {\rm{SGR}}}\nonumber\\ = \frac{{\left( {\it{In\ final\ weight\ - \ In\ initial\ weight}} \right)\ }}{{\it 14\ d\ }} \times \ 100\nonumber\\ \end{eqnarray} (6) \begin{eqnarray}{\rm{GE}} = \frac{{\ BWG\ }}{{\it{Initial\ weight} }}\end{eqnarray} (7) Blood Collection and Analysis From each pen, 2 broilers were chosen randomly for blood collection at 40 d of age. Blood was collected from the brachial vein using needle and syringe, and then transferred into 2 types of tubes. The blood samples were taken to Lancet laboratory (Mafikeng, SA) within 2 h of collection for blood analysis. An anti-coagulant was used for hematological analyses using a purple tube so that the blood does not clot. The Idexx lasercyte (hematology analyser) was used to analyze for hematocrit, hemoglobin, erythrocyte, leucocyte, neutrophils, lymphocytes, monocytes, eosinophil, and normoblasts. For serum biochemical indices, the tube without anticoagulant for serum (red tube) was used. The enzymes were analyzed using a clinical chemistry analyzer (Gilford Impact, 404lE, Ciba Coming Diagnostic Corp., Gilford Systems, Oberlin, OH). A UV–VIS spectrophotometer (SPECORD 50 PC, Analytik Jena AG) was used to perform the enzyme assays using respective commercial kits (Ciba Coming Diagnostic Corp., Gilford Systems, Oberlin, OH). The total protein (TP) and albumin, cholesterol, and mineral content were quantified using an auto-analyzer (Hitachi-704, Boehringer Mannheim Ltd, Germany). Statistical Analysis Data on growth, protein utilization efficiency, hematology and serum biochemistry parameters measured were analyzed using the GLM procedure of SAS (2010) with diet as the only fixed effect (model 1). Data on cumulative weight gain were measured on a weekly basis and were analyzed using the mixed model procedure of SAS (2010), which took into consideration the effect of both diet and wk of measurement (model 2) with diet as a fixed factor. The probability differences (PDIFF) option of SAS (2010) was used to perform pairwise comparisons of the least square means, while contrasts (SAS, 2010) were used to determine the specific effects of enzyme, organic acid, and their interaction on different parameters. The statistical models were as follows: \begin{eqnarray}{Y_{ij}} = {\rm{ }}\mu {\rm{ }} + {\rm{ }}{T_i} + {\rm{ }}{\varepsilon _{ij}}\end{eqnarray} (model 1) Where: Yij = observation (growth parameters and blood parameter), μ = population mean constant common to all observations, Ti = effect of diet, and εij = random error term. \begin{eqnarray}{Y_{ijk}} = {\rm{ }}\mu {\rm{ }} + {\rm{ }}{T_i} + {\rm{ }}{W_j} + {\rm{ }}{\left( {T{\rm{ }}*{\rm{ }}W} \right)_{ij}} + {\rm{ }}{\varepsilon _{ijk}}\nonumber \\\end{eqnarray} (model 2) Where: Yij = observation (cumulative weight gain parameter), μ = population mean constant common to the observation, Ti = effect of diet, T * Wij = effect of diet interacting with wk, and εij = random error term. For all tests, the level of significance was set at (P < 0.05). RESULTS Growth Performance The effects of humic acid and enzymes inclusion in canola diets on growth parameters of broilers at different feeding phases are presented in Table 4. Diet had no influence on ADFI in either grower or finisher phase. Similarly, dietary treatment had no effect on ADG or FCR of the broilers in the finisher feeding phase. On the contrary, significant (P < 0.05) differences in ADG and FCR of broilers in the grower phase were observed. In the grower phase, broiler chickens fed the CM diet had higher (P < 0.05) ADG (71 ± 1.08 g/d), while those in the control had the lowest (63.75 ± 1.81 g/d). In contrast, broilers in the control (1.65 ± 0.04) had the lowest (P < 0.05) FCR, while those in CM had the lowest (1.47 ± 0.04). No differences were observed in growth parameters in the finisher phase. Overall, the CMEnzPh fed broilers had higher ADG (P < 0.05) compared with those fed the control diet. However, no differences were observed in ADG between the control group and the CMEnz and CMPh treatment groups. In addition, no differences were observed in overall FCR between the control group and the CMEnz, CMPh, and CMEnzPh treatment groups. Table 4 Effect of enzyme complex and humic acid inclusion on growth performance of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ADFI = average daily feed intake; ADG = average daily gain; FCR = feed conversion ratio. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 4 Effect of enzyme complex and humic acid inclusion on growth performance of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase ADFI (g) 105.28 104.07 105.64 105.13 106.25 1.81 ADG (g/d) 63.75a 71.00b 66.86a,b 69.35b 68.35b 1.08 FCR 1.65b 1.47a 1.58a,b 1.52a,b 1.56a,b 0.04 Finisher phase ADFI (g) 182.91 178.17 185.76 181.91 182.57 3.26 ADG (g/d) 93.69 81.16 90.97 88.84 92.68 4.77 FCR 1.95 2.31 2.05 2.05 1.98 0.15 Overall performance ADFI (g) 144.1 141.12 145.7 143.52 144.41 3.12 ADG (g/d) 78.72b 76.08a 78.92b 79.1b 80.52c 2.65 FCR 1.8a,b 1.89c 1.82b 1.79a 1.77a 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ADFI = average daily feed intake; ADG = average daily gain; FCR = feed conversion ratio. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large The CWG of broilers over the experimental period is presented in Figure 1. A clear linear increase in weight gain was observed in both the grower and finisher feeding phases for all the diets except CM. The CWG of the control appeared to be depressed between wk 2 and 3, although it increased sharply thereafter. Among all treatments, the control had the lowest CWG (333.8 g/wk) compared to all the other treatments. No differences in CWG were observed for broilers fed CM or CMEnzPh. Nevertheless, broilers in CMEnzPh had the highest values of CWG throughout the feeding period. Broilers fed CM had the lowest final weight (2130.9 g), while those fed CMEnzPh had the highest (2254.4 g). Figure 1. View largeDownload slide Effect of potassium humate and Axtra XAP on cumulative weight gain on broiler chickens fed canola-based diets. Figure 1. View largeDownload slide Effect of potassium humate and Axtra XAP on cumulative weight gain on broiler chickens fed canola-based diets. Protein Utilization and Growth Efficiency The results of protein utilization and growth efficiency are presented in Table 5. Dietary treatment significantly (P < 0.05) affected protein utilization and growth efficiency parameters in both grower and finisher phases except for PC in the finisher phase. In the grower phase, PC was higher in CMEnzPh (20.12 g) and CMEnz compared with the control. However, CM and CMPh had the highest (P < 0.05) PER, while the control had the lowest. Specific growth rate was higher in CM than all other treatments. In all instances, the control had the lowest values for PER, SGR, and GE in the grower phase. On the contrary, in the finisher phase, although the control had the lowest value for PC, the values for PER, SGR, and GE were higher (P < 0.05) than all other treatments. Table 5. Effect of enzyme complex and humic acid inclusion on protein utilization efficiency of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 a,bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PC = protein consumed, PER = protein efficiency ratio, SGR = specific growth rate, GE = growth efficiency. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 5. Effect of enzyme complex and humic acid inclusion on protein utilization efficiency of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh SEM Grower phase PC (g) 18.95a 19.79a,b 20.00b 19.91a,b 20.12b 0.32 PER 3.36a,b 3.60c 3.34a 3.88d 3.41b 0.09 SGR (% d−1) 8.63a 9.22b 9.06b 8.95a 9.04b 0.16 GE 0.70a 0.72b 0.72b 0.71a,b 0.72b 0.01 Finisher phase PC (g) 14.99 13.71 15.33 15.00 15.65 0.80 PER 6.25b 5.92a 5.92a 5.92a 5.92a 0.00 SGR (% d−1) 5.05b 4.27a 4.86a,b 4.64 4.84a,b 0.19 GE 1.03b 0.84a 0.98a,b 0.91a,b 0.98a,b 0.04 a,bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PC = protein consumed, PER = protein efficiency ratio, SGR = specific growth rate, GE = growth efficiency. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Hematology Parameters The full blood parameters are presented in Table 6. As illustrated in the table, treatment had no effect on packed cell volume (PCV), hemoglobin (Hb), or the total red blood cell (RBC) count. However, diets affected (P < 0.05) total white blood cell counts (WBC) and all WBC differential counts. Interestingly, broilers fed CMEnz had the lowest amount of the WBC differential counts, while broilers fed CMEnzPh consistently had the highest (P < 0.05) counts. The neutrophil to WBC, lymphocytes to WBC, and neutrophil to lymphocytes ratios were not (P > 0.05) affected by the diet. Table 6. Effect of enzyme complex and humic acid inclusion on hematology of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PCV = packed cell volume, WBC = white blood cell, Neutro = neutrophils, and Lym = lymphocytes. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 6. Effect of enzyme complex and humic acid inclusion on hematology of broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh PCV (l/l) 0.36 ± 0.02 0.29 ± 0.02 0.34 ± 0.02 0.33 ± 0.02 0.32 ± 0.02 Haemoglobin (g/dl) 9.71 ± 0.44 7.91 ± 0.50 9.29 ± 0.50 8.70 ± 0.05 8.58 ± 0.54 Red blood cell (× 1012/l) 2.85 ± 0.14 2.37 ± 0.15 2.67 ± 0.15 2.68 ± 0.15 2.66 ± 0.17 White blood cell (× 109/l) 31.3 ± 4.80b 23.71 ± 5.45a 22.06 ± 5.45a 32.8 ± 5.45b 34.91 ± 5.88b Neutrophils (× 109/l) 4.86 ± 1.57b,c 1.76 ± 1.89a 2.61 ± 1.89a 3.22 ± 1.89b 5.51 ± 2.05c Lymphocytes (× 109/l) 22.7 ± 3.73b 18.8 ± 4.23a 16.31 ± 4.23a 23.65 ± 4.23b,c 26.08 ± 4.57c Monocytes (× 109/l) 0.52 ± 0.42a 0.35 ± 0.47a 1.12 ± 0.47c 0.77 ± 0.47b 1.13 ± 0.51c Eosinophils (× 109/l) 2.92 ± 0.93b 2.65 ± 1.05b 1.76 ± 1.05a 2.19 ± 1.05b 1.80 ± 1.14a Normoblasts (/100WBC) 0.00 ± 0.17a 0.19 ± 0.19a 0.16 ± 0.19a 0.14 ± 0.19a 0.38 ± 0.20b Neutro: WBC ratio 0.13 ± 0.03 0.08 ± 0.04 0.07 ± 0.04 0.09 ± 0.04 0.13 ± 0.04 Lym: WBC ratio 0.75 ± 0.05 0.79 ± 0.06 0.81 ± 0.05 0.68 ± 0.06 0.74 ± 0.06 Neutro: Lym ratio 0.18 ± 0.08 0.09 ± 0.09 0.09 ± 0.09 0.28 ± 0.09 0.19 ± 0.11 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: PCV = packed cell volume, WBC = white blood cell, Neutro = neutrophils, and Lym = lymphocytes. 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Serum Biochemical Parameters The serum biochemical indices presented in Table 7 show no dietary effect on liver enzymes or blood minerals apart from AST and sodium. Chickens offered the CM diet (406.86 ± 38.07 IU/L) had the highest levels (P < 0.05) of AST followed by CMEnz chickens (389.86 ± 38.07 IU/L). The CMEnzPh chickens had the lowest AST levels (254.17 ± 41.11 IU/L). The diet also affected the serum concentrations of sodium with CMPh chickens (150.57 ± 0.69 mmol/l) having the highest (P < 0.05) sodium content compared to the control, CM, and CMEnzPh (147.44, 147.14, and 147.16 mmol/l, respectively) chickens. Diet had no effect on total protein, serum albumin, cholesterol, or any other minerals. Table 7 Effect of enzyme complex and humic acid inclusion on serum biochemistry parameters in broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ALP = alanine aminotransferase, ALT = alkaline phosphatase and AST = aspartate aminotransferase; 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large Table 7 Effect of enzyme complex and humic acid inclusion on serum biochemistry parameters in broilers fed canola-based diets. Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 Dietary treatments2 Parameters1 Control CM CMEnz CMPh CMEnzPh ALP (IU/L) 1835.56 ± 217.52 1723.86 ± 246.64 2313.43 ± 246.64 2401.57 ± 246.64 2330.83 ± 266.40 ALT (IU/L) 2.67 ± 0.48 3.00 ± 0.55 3.00 ± 0.55 2.00 ± 0.55 1.50 ± 0.59 AST (IU/L) 288.78 ± 33.57a,b 406.86 ± 38.07b 389.86 ± 38.07a,b 313.57 ± 38.07a,b 254.17 ± 41.11a Total protein (g/l) 27.89 ± 0.91 26.00 ± 1.02 27.28 ± 1.02 27.14 ± 1.02 26.17 ± 1.10 Sodium (mmol/l) 147.44 ± 0.62a 147.14 ± 0.69a 148.00 ± 0.69a,b 150.57 ± 0.69b 147.16 ± 0.75a Potassium (mmol/l) 5.71 ± 0.29 4.93 ± 0.33 4.58 ± 0.33 5.47 ± 0.33 5.17 ± 0.36 Albumin (g/l) 11.56 ± 0.35 11.14 ± 0.40 11.57 ± 0.40 12.14 ± 0.40 11.33 ± 0.43 Calcium total (mmol/l) 2.52 ± 0.06 2.49 ± 0.07 2.58 ± 0.07 2.54 ± 0.07 2.44 ± 0.81 Cholesterol (mmol/l) 3.05 ± 0.14 2.92 ± 0.16 3.40 ± 0.16 3.35 ± 0.16 2.98 ± 0.18 Magnesium (mmol/l) 0.98 ± 0.03 0.94 ± 0.27 0.93 ± 0.30 1.01 ± 0.30 0.98 ± 0.33 a-bMeans in the same row with different superscripts are significantly different (P < 0.05). 1Parameters: ALP = alanine aminotransferase, ALT = alkaline phosphatase and AST = aspartate aminotransferase; 2Dietary treatments: Control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion + 0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion + 1.5% potassium humate, PH), and CMEnzPh (17.5% CM inclusion + 1.5% PH + 0.3 g/kg Axtra XAP). View Large DISCUSSION The lack of dietary treatment effects on the ADFI for both grower and finisher phases suggests that canola inclusion level (17.5%) was within the optimal range and, therefore, did not cause any significant changes in physico-chemical properties of the diets. Generally, raw ingredients used in the formulation of diets have an influence on physico-chemical properties of the diets that may affect the taste, palatability, and functional properties of the diets, ultimately altering feed intake in broilers. The lack of dietary treatment effects on the ADFI also could be explained by the fact that the broilers, at the grower stage, have a fully developed digestive system to cope with the higher fiber and secondary plant metabolites, particularly glucosinolates, which characterize the CM (Mailer et al., 2008). The CM used in the current study had high fiber (12%) and lower protein (36 to 39%) compared to SBM. It also contained considerable amounts of glucosinolates (3.8 μmol/g), but these were not significant enough to affect the performance of the birds. The high fiber content in canola could therefore have reduced feed intake, resulting in lower BWG of broiler chickens (Widyaratne and Drew, 2011). However, ADG was higher in canola-containing diets, while FCR also was improved. The higher ADG and reduced FCR in canola-containing treatments could be attributed to humic acid and enzymes, which may have improved the feed efficiency given the reduced feed intake. Growth promoting agents such as humic acid and exogenous enzymes have been observed to improve digestion and feed utilization dynamics of poor protein sources (Ferket and Gernat, 2006; Rath et al., 2006; Toghyani et al., 2010). The results of the current study from both feeding phases indicated that feeding enzymes improved feed utilization of canola-based diets, as was observed in other studies (Pucci et al, 2010; Tang et al. 2014). Cowieson and Ravindran (2008) also observed that addition of enzymes in broiler diets had a positive influence on the overall performance of broilers. However, Kocher et al. (2003) observed that an enzymes-only diet had a slight influence on overall performance of broilers. In addition, other researchers observed that addition of an enzyme complex had a negative influence on performance variables (Brufau et al., 2006; Yegani and Korver, 2013). Nevertheless, the positive effects observed in the current study indicate that Axtra XAP was effective in the breakdown of the matrix of cell walls in fibrous canola, thus helping the release of nutrients captured in cell walls due to easier access of digestive enzymes to these substrates, as observed in other studies (Fang et al., 2007; Christian and Mellor, 2011; Dehghani-Taftia and Jahaniana, 2016; Ragaa and Korany, 2016). The high PER observed in the CMPh and CMEnzPh compared to the control diet could be due to the effects of humic acids in enhancing peptic activities and increasing N digestibility through alteration of gut pH (Christian and Mellor, 2011; Ragaa and Korany, 2016). Overall, hematological indices were observed to be within the anticipated ranges for healthy broilers (Merck Manual, 2012). This implies that the inclusion of CM and the growth-promoting agents did not influence hematopoiesis. In fact, the desirable blood metabolite levels realized in the current study indicates the potential of the humic acid and CM in improving the general health status of broilers. In other studies, compounds of a similar nature were observed to reduce the hematological disorders associated with aflatoxins and mycotoxins in feeds (Abdel-Wahhab and Aly, 2005; Ozturk et al., 2012). Generally, hematological indices are normally indicative of the health status of animals. In the current study, no effect of diet was observed on the lymphocyte to WBC, neutrophil to WBC, or neutrophil to lymphocyte ratios. The WBC ratios could be used as reliable biomarkers that indicate any inflammations stimulated by feed-induced stress. Currently, information on the use of such ratios in assessing the effects of unconventional dietary additives on the general health of broilers is largely unavailable. The serum metabolites observed were all within normal ranges for healthy broiler chickens (Merck Manual, 2012). Serum biochemical indices normally reflect the condition of an animal and any changes in response to internal and exogenous factors (Toghyani et al., 2010). Measuring these parameters is significant for monitoring the general health and nutritional status of broilers. Although AST levels were higher for the birds fed canola diets, the levels were still within the normal ranges. Nevertheless, the observed high levels of AST in CM and CMEnz could perhaps be due to an increased liver activity in an attempt to detoxify the higher amounts of secondary plant metabolites in canola. Generally, higher levels of liver enzyme above the normal ranges signify liver damage (hepatocellular degeneration; Badari et al., 2003). This also may be manifested in reduced blood flow (ischemia) to the liver (Khajali and Slominski, 2012). Interestingly, the AST values in chickens offered potassium humate-containing diets were similar to those of the chickens fed the control diet. This may be indicative of the hepato-protective abilities of potassium humate in reducing free radicals induced by increased amounts of secondary plant metabolites in canola, which could have caused liver damage (Hern´andez et al., 2006). As observed in other studies, no variation in protein concentration or total albumin was observed in the current study. Together with other serum metabolites, protein concentration gives an indication of the adequacy of protein in the diet and the efficiency with which it is being utilized by the broilers (Ghammry et al., 2002). The results, therefore, imply that the inclusion of canola in diets did not impede protein digestion or utilization by broiler chickens. In conclusion, our results showed that inclusion of humic acid and enzymes in canola-based diet positively influenced growth performance and health status of broilers fed canola-based diets. Growth performance indices of broilers fed supplemented canola-based diets were improved due to the growth-promoting effects of humic acid and enzymes, which resulted in improved feed utilization efficiency. The low AST levels in chickens fed diets containing humic acid indicates the hepato-protective ability of humic acid. Overall, CM was shown to have great potential as an alternative replacement of SBM in broiler diets. 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Poultry ScienceOxford University Press

Published: Jul 11, 2018

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