TY - JOUR
AU1 - Arias, R. P.
AU2 - Unruh-Snyder, L. J.
AU3 - Scholljegerdes, E. J.
AU4 - Baird, A. N.
AU5 - Johnson, K. D.
AU6 - Buckmaster, D.
AU7 - Lemenager, R. P.
AU8 - Lake, S. L.
AB - ABSTRACT Two experiments were conducted to evaluate the effect of feeding corn modified wet distillers grain plus solubles (MWDGS; 48% DM) co-ensiled with chopped whole plant corn (WC) on growth performance, dietary intake, and nutrient digestibility of beef cattle. In Exp. 1, 96 Angus-crossed heifers (2 yr old; 522 ± 49.1 kg BW; 5.3 ± 0.1 BCS) were stratified and blocked according to BW and stratified by BCS in each block in a randomized complete block design (24 pens; 4 heifers/pen; 6 treatment replications). Groups were assigned to 1 of 4 dietary treatments for a 62 d trial. Treatments were 1) corn silage (CS) and soybean meal (CON), 2) MWDGS co-ensiled with chopped whole plant corn (WC; CO-EN), 3) CS mixed with MWDGS at feeding (CS+WDG), and 4) CS mixed with dry distillers grain plus solubles (DDGS) at feeding (CS+DDG). In Exp. 2, 4 crossbred beef steers (initial BW = 278 ± 18 kg) fitted with permanent ruminal cannulas were used in a balanced 4 × 4 Latin square to test the effects of feeding MWDGS co-ensiled with WC on DM intake, ruminal fermentation characteristics, and total tract digestibility. There were four 14-d periods, with 10 d for diet adaptation and 4 d for samples collection. Orthogonal contrasts were used and compared CON vs. diets containing distillers grains (DGD), CO-EN vs. diets where distillers grains were mixed at feeding (MIX), and CS+WDG vs. CS+DDG. In Exp. 1, the CON fed heifers resulted in greater G:F (P = 0.04) compared with those fed DGD. However, ADG (P = 0.03), final BW (P = 0.04), and BW gain (P = 0.03) were greatest for DGD diets compared with CON and greatest (P = 0.04) for CO-EN when compared with MIX. Apart from a slightly greater acetate concentration (P = 0.05), which resulted in a greater acetate to propionate ratio (P = 0.03) for the CON diet compared with DGD, no important differences were observed on intake, diet digestibility, or fermentation characteristics when comparing the CON treatment with DGD or when comparing CS+WDG with CS+DDG. However, the CO-EN diet resulted in decreased DMI (P = 0.05) and consequently decreased OM (P = 0.05), N (P = 0.04), and NDF (P = 0.02) intakes compared with MIX. Data from these studies suggest that MWDGS co-ensiled with WC can successfully replace traditional corn-based diets supplemented with soybean meal and corn silage diets supplemented with distillers grains without compromising digestibility and growth performance in pregnant heifers. INTRODUCTION In the United States, corn distillers grain plus solubles (DGS) have cost-effectively replaced corn and soybean meal in cattle diets with inclusion levels of up to 40% (DM basis) without compromising growth or reproductive performance. In some cases DGS resulted in improved gain and reproductive efficiency of beef heifers (Stalker et al., 2006; Vander Pol et al., 2009). According to a survey by Vasconcelos and Galyean (2007), 83% of the feedlots in the United States use grain co-products in their diets, with dry DGS (DDGS; >85% DM) and wet DGS (WDGS; 30 to 50% DM) being the preferred. Wet DGS have a nutritional and economic advantage over DDGS if managed correctly, and WDGS have greater energy concentrations, less heat damaged protein, and lower price per unit of DM compared with DDGS (Dooley et al., 2008). However, WDGS have disadvantages such as greater transportation cost per unit of DM, difficult storage and handling, and a reduced shelf life (Lemenager et al., 2006). There are few peer-reviewed publications in regards to how co-ensiled rations affect growth performance characteristics on beef heifers. Successful co-ensiling of WDGS with chopped whole plant corn, corn stalks, fresh cut grass, hay, soybean hulls, wheat straw, and wet beet pulp has been reported (Johnson et al., 1987; Kalscheur et al., 2004; Erickson et al., 2008; Gunn, 2008; Anderson et al., 2009). Co-ensiling WDGS with other feeds can result in a stable mixture that constitutes a viable way to store WDGS for long periods of time (Buckmaster et al., 2008). We hypothesized that heifers fed modified WDGS co-ensiled with chopped whole plant corn would perform equally or better than heifers fed traditional corn silage diets supplemented with soybean meal and diets where DGS were added at the time of feeding. The objective of this study was to determine the effects of feeding modified WDGS co-ensiled with chopped whole plant corn on growth performance, total intake, and diet digestibility of beef cattle. MATERIALS AND METHODS All animal care, handling and surgical procedures were approved by the Purdue Animal Care and Use Committee before initiation of experiments. A licensed veterinarian at Purdue University Veterinary Clinical Sciences performed surgical placement of cannulas for steers used in Exp. 2. A 2-mo postsurgery period was allowed before initiation of the experiments. All experiments were performed at Purdue University's Beef Unit, located in the Animal Sciences Research Center in West Lafayette, IN. Experiment 1 Animals Ninety-six 2-yr-old, commercial Angus heifers (initial BW = 522 ± 49.1 kg; initial BCS = 5.3 ± 0.1) in their last trimester of gestation were used in this experiment. Heifers were weighed, body condition scored at the beginning of the trial, and stratified and blocked according to BW and stratified by BCS in each block in a randomized complete block design (24 pens; 4 heifers/pen; 6 treatment replications). Groups were assigned to 1 of 4 dietary treatments for a 62-d trial and housed in 3.0- by 9.1-m pens constructed of steel gates, inside a 3-sided barn with concrete floors covered with straw. Body condition scores were taken and averaged by 2 trained technicians throughout the study (Lake et al., 2005). Initial and final BW were the average of BW taken before feeding time on 2 consecutive days, and corrected for days of gestation using this equation:  in which GU stands for gravid uterus (fetus, fetal membranes, fetal fluids, and uterus), and t is the status of pregnancy in days (Ferrell et al., 1976), in this case determined by days after AI. Ten days after timed AI (TAI), intact bulls that were tested by a trained veterinarian for disease and fertility were placed with the heifers for 45 d. Pregnancy diagnosis was performed 35 d after TAI using transrectal ultrasonography (variable megahertz linear array transducer; MicroMaxx; Sonosite, Bothell, WA) to determine conception during the synchronized period. One heifer was removed from the experiment due to a nontreatment related abortion during the second half of the experiment. Diets Detailed ingredient and chemical composition of diets used in this experiment can be found in Table 1. Diets consisted of 4 total mixed rations (TMR): 1) corn silage (CS) and soybean meal (CON), 2) corn modified wet distillers grain plus solubles (MWDGS) co-ensiled with chopped whole plant corn (WC; CO-EN), 3) CS mixed with MWDGS at feeding (CS+WDG), and 4) CS mixed with DDGS at feeding (CS+DDG). All diets were balanced to meet NRC (2000) requirements of beef heifers in late pregnancy, were formulated to be isocaloric and isonitrogenous, and contained 1.9% of a mineral supplement composed of 75.0% CaCO3, 10% salt, 5.69% urea, 4.49% Ackey mineral (Dayton, OH), 0.52% Rumensin 80 (34 mg Monensin/kg; Elanco Animal Health, Indianapolis, IN), and 0.126% Tylan 100 (36 g Tylosin/kg; Elanco Animal Health). Heifers were limit fed once daily at approximately 0800 h to attain an ADG of 0.23 kg/d and had free access to water. All distillers grain products were acquired from the same ethanol plant (Iroquois Bio-Energy Company, LLC, Rensselaer, IN). Modified wet distillers grains were stored outdoors over a concrete floor; 2 separate but similar in composition batches of MWDGS were used in the experiment. Table 1. Ingredient and analyzed nutrient composition of diets used in Exp. 1   Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.0  –  73.6  73.6      Soybean meal  10.1  –  –  –      Co-ensiled5  –  98.1  –  –      MWDGS6  –  –  24.5  –      DDGS7  –  –  –  24.5      Mineral premix8  1.9  1.9  1.9  1.9  Chemical composition9      DM, %  38.3  36.1  40.5  38.8      NEg, Mcal/kg  1.10  1.19  1.16  1.12      CP, %  12.53  13.46  13.85  14.26      NDF, %  33.6  30.8  26.9  31.8      ADF, %  17.6  15.7  13.9  15.3    Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.0  –  73.6  73.6      Soybean meal  10.1  –  –  –      Co-ensiled5  –  98.1  –  –      MWDGS6  –  –  24.5  –      DDGS7  –  –  –  24.5      Mineral premix8  1.9  1.9  1.9  1.9  Chemical composition9      DM, %  38.3  36.1  40.5  38.8      NEg, Mcal/kg  1.10  1.19  1.16  1.12      CP, %  12.53  13.46  13.85  14.26      NDF, %  33.6  30.8  26.9  31.8      ADF, %  17.6  15.7  13.9  15.3  1Diets were based on NRC (2000) requirements. 2DM basis. 3CON = corn silage and soybean meal; CO-EN = chopped whole plant corn (WC) co-ensiled with corn modified wet distillers grain plus solubles (MWDGS); CS+WDG = corn silage mixed with MWDGS added at feeding; CS+DDG = corn silage mixed with DDGSat feeding. 4Corn silage: 35% DM, 9.1% CP, 40% NDF (DM basis). 5Silage mix of 75% WC (35% DM, 9.1% CP, and 40% NDF) and 25% MWDGS on a DM basis. 6Contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). 7Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 8Composed of 75.0% CaCO3, 10% salt, 5.69% urea, 4.49% Ackey mineral (Dayton, OH), 0.52% Rumensin 80 mg/d (80 g Monensin per lb; Elanco Animal Health, Indianapolis, IN), and 0.126% Tylan 100 (100 g Tylosin per lb; Elanco Animal Health). 9Based on values obtained from complete mixed feed samples in a laboratory. View Large Table 1. Ingredient and analyzed nutrient composition of diets used in Exp. 1   Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.0  –  73.6  73.6      Soybean meal  10.1  –  –  –      Co-ensiled5  –  98.1  –  –      MWDGS6  –  –  24.5  –      DDGS7  –  –  –  24.5      Mineral premix8  1.9  1.9  1.9  1.9  Chemical composition9      DM, %  38.3  36.1  40.5  38.8      NEg, Mcal/kg  1.10  1.19  1.16  1.12      CP, %  12.53  13.46  13.85  14.26      NDF, %  33.6  30.8  26.9  31.8      ADF, %  17.6  15.7  13.9  15.3    Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.0  –  73.6  73.6      Soybean meal  10.1  –  –  –      Co-ensiled5  –  98.1  –  –      MWDGS6  –  –  24.5  –      DDGS7  –  –  –  24.5      Mineral premix8  1.9  1.9  1.9  1.9  Chemical composition9      DM, %  38.3  36.1  40.5  38.8      NEg, Mcal/kg  1.10  1.19  1.16  1.12      CP, %  12.53  13.46  13.85  14.26      NDF, %  33.6  30.8  26.9  31.8      ADF, %  17.6  15.7  13.9  15.3  1Diets were based on NRC (2000) requirements. 2DM basis. 3CON = corn silage and soybean meal; CO-EN = chopped whole plant corn (WC) co-ensiled with corn modified wet distillers grain plus solubles (MWDGS); CS+WDG = corn silage mixed with MWDGS added at feeding; CS+DDG = corn silage mixed with DDGSat feeding. 4Corn silage: 35% DM, 9.1% CP, 40% NDF (DM basis). 5Silage mix of 75% WC (35% DM, 9.1% CP, and 40% NDF) and 25% MWDGS on a DM basis. 6Contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). 7Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 8Composed of 75.0% CaCO3, 10% salt, 5.69% urea, 4.49% Ackey mineral (Dayton, OH), 0.52% Rumensin 80 mg/d (80 g Monensin per lb; Elanco Animal Health, Indianapolis, IN), and 0.126% Tylan 100 (100 g Tylosin per lb; Elanco Animal Health). 9Based on values obtained from complete mixed feed samples in a laboratory. View Large The co-ensiled product consisted of 75% WC (35% DM, 9.1% CP, and 40% NDF; DM basis) mixed with 25% MWDGS (48% DM, 28% CP, and 30% NDF; DM basis). In the making, WC and MWDGS were weighed and mixed using a horizontal Oswalt TMR mixer (J-STAR, Fort Atkinson, WI), bagged using an Ag-Bagger (Ag-bag International, Ltd., Warrenton, OR), and allowed to ensile for a minimum of 28 d before being fed. Moisture content of the WC and MWDGS was continuously monitored to ensure a moisture content of the mix that would allow for proper fermentation. Forage used to manufacture the co-ensiled product came from the same corn field as the one used to make the plain CS used in the other 3 diets. Sampling Feed samples were collected every 15 d and stored in a freezer until further analyses were conducted. Samples were dried in a forced air oven at 60°C for 48 h, ground to pass a 1-mm screen (Udy Cyclone mill; UDY Corp., Fort Collins, Co), and analyzed for DM, OM, and ash (AOAC, 1990). Neutral and acid detergent fiber fractions were determined by ANKOM 2000 Fiber Analyzer (ANKOM Corp., Fairport, NY). Nitrogen was determined via block digestion (AOAC, 1990; method 976.06) and steam distillation with MgO using a 2300 Kjeltec Analyzer Unit (FOSS TECATOR AB, Foss North America, Eden Prairie, MN). Crude protein was calculated by multiplying N percent by 6.25. Net energy for growth was determined by a commercial laboratory (Sure-Tech Laboratories, Indianapolis, IN). Weekly samples of all feedstuffs were collected and dried to monitor DM and adjust the rations accordingly. Statistical Analysis Heifer performance was measured in terms of intake, ADG, G:F, change in BW, and change in BCS and data were analyzed using the GLM procedures (SAS Inst. Inc., Cary, NC) for a randomized complete block design. Heifers were stratified and blocked according to BW and stratified by BCS in each block in a randomized complete block design (24 pens; 4 heifers/pen; 6 treatment replications). The fixed effect of treatment was included in the model, with pen serving as the experimental unit with pen location (within barn) serving as a block. The 2-way interaction of treatment × block was initially included in the statistical model and subsequently removed if not significant (P > 0.05). Three linear orthogonal contrasts were used and compared CON vs. diets containing distillers grains (DGD), CO-EN vs. diets where distillers grains were mixed at feeding (MIX), and CS+WDG vs. CS+DDG. Because heifers were limit fed to a similar DMI and a difference (P < 0.05) in DMI was found between treatments, DMI was introduced in the model as a covariate to analyze performance variables. Predicted values result using the covariate were not different (P > 0.05) than arithmetic means; therefore, the unadjusted arithmetic means are presented for all performance variables. Treatment differences were considered significant at α = 0.05 and a trend when 0.05 < α ≤ 0.10. Experiment 2 Animals Four crossbred beef steers (initial BW = 278 ± 18 kg) fitted with permanent ruminal cannulas (10 cm i.d.; Bar Diamond, Parma, ID) were used in a balanced 4 × 4 Latin square to test the effects of feeding MWDGS co-ensiled with WC on DM intake, ruminal fermentation characteristics, and total tract digestibility. There were four 14-d periods, with 10 d for diet adaptation and 4 d for samples collection. Steers were weighed at the initiation of the experiment and housed individually in 3.0- by 9.1-m outdoor pens during the first 9 d of every adaptation period. Pens were inside a 3-sided barn and consisted of concrete floors covered with woodchips. On d 10, steers were moved into a climate-controlled room with temperatures maintained between 17 and 21°C and continuous lighting. Individual 1.0- by 2.0-m tie stalls were equipped with rubber mats and designed for total urine and fecal collections. At the end of d 14, steers were allowed access to pasture for 12 h to provide exercise before initiation of next period. Steers had free access to water at all times during the experiment. Diets Formulation and ingredient composition of diets used in this study can be found in Table 2. Steers had free access to water and were fed once a day at approximately 0800 h. Steers were fed ad libitum by offering 10% above previous day intake. Diets were fed as a TMR and were mixed using a Kelly Duplex series 57261 horizontal paddle mixer (Kelly Duplex Mill and Manufacturing Co., Springfield, OH) every 3 d and stored in a freezer room at –20°C until fed. Diets were balanced to meet or exceed NRC (2000) requirements of beef finishing steers. Corn modified wet distillers grain plus solubles used in the CS+WDG diet belonged to the same batch and were stored in 208 L containers inside a walk-in cooler (4.0°C) throughout the experiment. Table 2. Ingredient and analyzed chemical composition of diets fed to ruminally fistulated steers in Exp. 2   Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.6  –  68.7  68.8      Corn gluten meal  9.1  –  –  –      Soybean meal  –  0.8  0.8  0.8      Co-ensiled5  –  96.8  –  –      MWDGS6  –  –  28.1  –      DDGS7  –  –  –  28.0      Mineral premix8  2.3  2.4  2.4  2.4  Chemical composition9      DM, %  39.9  39.3  39.7  45.1      NEg, Mcal/Kg  1.10  1.19  1.12  1.17      CP, %  12.6  13.4  13.5  13.6      NDF, %  32.9  32.5  36.0  35.4      TDN,10 %  76.7  73.6  73.6  73.6    Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.6  –  68.7  68.8      Corn gluten meal  9.1  –  –  –      Soybean meal  –  0.8  0.8  0.8      Co-ensiled5  –  96.8  –  –      MWDGS6  –  –  28.1  –      DDGS7  –  –  –  28.0      Mineral premix8  2.3  2.4  2.4  2.4  Chemical composition9      DM, %  39.9  39.3  39.7  45.1      NEg, Mcal/Kg  1.10  1.19  1.12  1.17      CP, %  12.6  13.4  13.5  13.6      NDF, %  32.9  32.5  36.0  35.4      TDN,10 %  76.7  73.6  73.6  73.6  1Diets were based on NRC (2000) requirements. 2DM basis. 3CON = corn silage and corn gluten meal; CO-EN = chopped whole plant corn (WC) co-ensiled with corn modified wet distillers grain plus solubles (MWDGS); CS+WDG = corn silage mixed with MWDGS added at feeding; CS+DDG = corn silage mixed with DDGS at feeding. 4Corn silage contained 35% DM, 9.1% CP, and 40% NDF (DM basis). 5Silage mix of 75% WC (35% DM, 9.1% CP, and 40% NDF) and 25% MWDGS on a DM basis. 6Contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). 7Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 8Composed of 75.0% CaCO3, 10% salt, 5.69% urea, 4.49% Ackey mineral (Dayton, OH), 0.52% Rumensin 80 mg/d (80 g Monensin per lb), and 0.126% Tylan 100 (100 g Tylosin per lb). 9Based on values obtained from complete mixed feed samples in a laboratory. 10TDN = total digestible nutrients (calculated from analyzed digestible energy values). View Large Table 2. Ingredient and analyzed chemical composition of diets fed to ruminally fistulated steers in Exp. 2   Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.6  –  68.7  68.8      Corn gluten meal  9.1  –  –  –      Soybean meal  –  0.8  0.8  0.8      Co-ensiled5  –  96.8  –  –      MWDGS6  –  –  28.1  –      DDGS7  –  –  –  28.0      Mineral premix8  2.3  2.4  2.4  2.4  Chemical composition9      DM, %  39.9  39.3  39.7  45.1      NEg, Mcal/Kg  1.10  1.19  1.12  1.17      CP, %  12.6  13.4  13.5  13.6      NDF, %  32.9  32.5  36.0  35.4      TDN,10 %  76.7  73.6  73.6  73.6    Dietary treatments1,2,3  Item  CON  CO-EN  CS+WDG  CS+DDG  Ingredient, %      Corn silage4  88.6  –  68.7  68.8      Corn gluten meal  9.1  –  –  –      Soybean meal  –  0.8  0.8  0.8      Co-ensiled5  –  96.8  –  –      MWDGS6  –  –  28.1  –      DDGS7  –  –  –  28.0      Mineral premix8  2.3  2.4  2.4  2.4  Chemical composition9      DM, %  39.9  39.3  39.7  45.1      NEg, Mcal/Kg  1.10  1.19  1.12  1.17      CP, %  12.6  13.4  13.5  13.6      NDF, %  32.9  32.5  36.0  35.4      TDN,10 %  76.7  73.6  73.6  73.6  1Diets were based on NRC (2000) requirements. 2DM basis. 3CON = corn silage and corn gluten meal; CO-EN = chopped whole plant corn (WC) co-ensiled with corn modified wet distillers grain plus solubles (MWDGS); CS+WDG = corn silage mixed with MWDGS added at feeding; CS+DDG = corn silage mixed with DDGS at feeding. 4Corn silage contained 35% DM, 9.1% CP, and 40% NDF (DM basis). 5Silage mix of 75% WC (35% DM, 9.1% CP, and 40% NDF) and 25% MWDGS on a DM basis. 6Contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). 7Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 8Composed of 75.0% CaCO3, 10% salt, 5.69% urea, 4.49% Ackey mineral (Dayton, OH), 0.52% Rumensin 80 mg/d (80 g Monensin per lb), and 0.126% Tylan 100 (100 g Tylosin per lb). 9Based on values obtained from complete mixed feed samples in a laboratory. 10TDN = total digestible nutrients (calculated from analyzed digestible energy values). View Large Sampling Protocol Orts were collected and weighed each morning before feeding. Samples of feed offered and orts were collected daily starting 1 d before the collection period. A set of feed and orts samples were placed in sealed plastic bags and stored at –20°C; a second set of feed samples were weighed and dried in a forced air oven (Tru-Temp; Hotpack Corp., Philadelphia, PA) at 55°C for 48 h and stored until analyzed. Total fecal output was collected into metal pans built into the floor and situated at the tail end of the tie stall designed to collect all fecal material during d 11 to 13 starting 4 h after feeding and every 4 h each day. The sampling times were advanced 2 h on d 12 to yield 12 samples that represent every 2-h collections during a 24-h period. Fecal output was recorded and sampled at approximately 10% (wet weight) of each 4-h collection. A fecal grab sample was weighed, dried in a forced air oven at 55°C for 72 h, composited on an equal weight basis, and stored in sealed plastic bags until further processing for analysis. Total fecal output was used in the calculation of apparent total-tract digestibility. A separate stainless-steel pan located under the crate and covered by a steel grate drained to a plastic bucket allowing for total urine collection. Ten milliliters of 6 N HCl were added to each empty bucket between each 4 h collection period to reduce the pH to 3.0 or below to avoid N volatilization and reduce microbial activity. Urine output was collected in the same timely manner as fecal output. Urine volume was measured every 4 h; a 100-mL sample was filtered through Whatman filter paper number 4 and acidified with 6 N HCl as needed. Samples were immediately stored in plastic screw-cap beakers inside a freezer (–20°C) until analyzed. Liquid dilution rate was estimated using Co-EDTA as a liquid flow marker. A 200 mL dose of Co-EDTA (4.0 g of cobalt; Uden et al., 1980) was delivered intraruminally immediately after feeding on d 13 of each collection period, and ruminal samples were collected at 0, 2, 4, 6, 8, 12, 16, 20, 24, 30, and 36 h after feeding. Whole ruminal fluid contents (approximately 300 mL) were sampled by manually removing a composite digesta sample from different locations within the rumen. Samples were strained through 4 layers of cheesecloth and pH was determined immediately with a portable pH meter (model miniLab IQ125; IQ Scientific Instruments, Inc., Carlsbad, CA); the fluid portion was transferred into duplicate 50 mL plastic centrifuge tubes, and each tube was acidified with 1 mL of 6 N HCl and immediately frozen (–20°C) until analyzed for VFA, Co, and rumen NH3. Blood samples were collected once daily via coccygeal venipuncture into 5 mL EDTA-lined vacutainer tubes (Tyco Healthcare Group LP, Mansfield, MA) from d 11 to d 14 to represent 0, 2, 4, and 8 h after feeding. Blood samples were immediately stored in ice for approximately 6 h until centrifugation at 10,000 × g for 20 min at 4°C. Serum was transferred into 5 mL polystyrene tubes and stored at –20°C until analyzed for blood urea nitrogen (BUN). Laboratory Analysis Feed offered, orts, and fecal samples were first ground to pass a 3-mm screen (Wiley mill; Arthur Hill Thomas Co., Philadelphia, PA), composited for each steer within each period, and then ground to pass a 1-mm screen (Udy Cyclone mill; UDY Corp., Fort Collins, Co). Samples were analyzed for DM, OM, and ash by standard procedures (AOAC, 1990). Neutral and acid detergent fiber fractions and CP were determined as in Exp. 1. Composite fecal samples were analyzed for DM by drying for 24 h at 100°C, and total DM fecal output was used in digestibility calculations. Urine samples were thawed at room temperature for approximately 2 h, composited (equal volume daily) for each steer within each period, and analyzed for urinary urea-nitrogen by the diacetyl monoxime method of Marsh et al. (1957) using a commercial kit (Stanbio Urea Nitrogen Kit, Procedure number 0580; Stanbio Laboratories, Boerne, TX 78006). Blood plasma samples were analyzed for BUN using the same commercial kit (inter- and intra-assay CV were 5.39 and 3.14, respectively). Ruminal fluid samples were thawed at 4°C for 12 h and centrifuged at 20,000 × g for 20 min at 4°C, and the supernatant fraction was collected for analysis of Co, ruminal NH3, and VFA concentrations. Ruminal VFA concentrations (acetate, propionate, butyrate, isobutyrate, valerate, and isovalerate) were quantified by gas chromatography (GC/FID; Model 7890A; Agilent Technologies, Santa Clara, CA) using a Nukol capillary column (30 m by 0.25 mm by 25 µm; Supelco, Bellefonte, PA) equipped with a flame ionization detector; 2-ethylbutyric acid was used as the internal standard (Goetsch and Galyean, 1983; inter- and intra-assay CV were 3.38 and 1.69, respectively). It has been suggested that fermentation peaks 4 h after feeding (Van Soest, 1994); therefore, rumen NH3 concentration comparisons between treatments was only made for samples taken 4 h after feeding by steam distillation with MgO, using a 2300 Kjeltec Analyzer Unit (FOSS TECATOR AB, Foss North America, Eden Prairie, MN; inter- and intra-assay CV were 1.97 and 2.09 respectively). Cobalt concentrations were determined as described by Uden et al. (1980) using an air-plus-acetylene flame by atomic absorption spectroscopy (Model 3110; PerkinElmer, Inc., Norwalk, CT). Statistical Analysis All intake, digestion, and passage data were statistically analyzed using the GLM procedure of SAS for a Latin square design, using steer (random effect) × period (fixed effect) as the experimental unit. No interactions were detected for period × treatment (P = 0.09) or individual animal × treatment (P = 0.11); therefore, only single-degree-of-freedom comparisons of CON vs. DGD, CO-EN vs. MIX, and CS+WDG vs. CS+DDG were reported. Digestion criteria were analyzed using a model containing digestibility parameters as dependent variables and treatment, period, and animal as independent variables. Treatment differences were considered significant at α = 0.05 and a trend when 0.05 < α ≤ 0.10. RESULTS AND DISCUSSION Experiment 1 Proximate analysis results of diets showed similar CP, NEg, and NDF levels among treatments (Table 1). Heifers fed the MIX diets had decreased DMI (P < 0.01) compared with heifers fed the CO-EN diet (Table 3). Because heifers in this study were limit fed to achieve similar DMI, DMI was tested as a covariate for all variables to determine if it had any effects on performance results; however, the intercept-slope covariance estimate was not statistically different from 0 for any variable (P > 0.10); therefore, arithmetic means are presented for all variables. The reduced DMI on the CS+WDG and CS+DDG diets may be due to improved aerobic stability (time to achieve 2°C temperature rise; Muck, 2004) on the co-ensiled material as reported by Gunn (2008), which could ultimately affect palatability. Buckmaster et al. (2008) reported a 16 h increase in stability for each 10% addition of WDGS (as-is basis). Nevertheless, the 3 DGD treatments had similar G:F when compared among themselves, and the CON fed heifers had greater G:F (P = 0.04) compared with those fed DGD. In contrast, ADG was greatest for DGD when compared with CON (P = 0.03) and greatest for CO-EN when compared with the MIX (P = 0.04). Although no differences were observed in final BCS or change in BCS, final BW (P = 0.04) and BW gain (P = 0.03) were greater for DGD diets when compared with CON and greatest (P = 0.04) for the CO-EN diet when compared with the other 2 diets containing DGS. Limited peer reviewed research can be found where these types of diets are limit fed and results vary in terms of DMI, feed, and BW gain efficiencies when comparing corn-based diets with distillers grain diets. Engel et al. (2005) reported similar final BCS and greater BW gains in heifers fed a 40% DDGS (DM basis) diet when compared with a SBM control diet. In contrast, Martin et al. (2007) reported no differences in final BW, final BCS or ADG between heifers fed prairie hay and supplemented with either DDGS or corn gluten feed. Table 3. Effects of corn modified wet distillers grain plus solubles co-ensiled with whole plant chopped corn on growth performance of pregnant heifers (Exp. 1)   Treatments1    Contrasts3  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM2  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  DM intake, kg/d  8.23  8.32  8.18  8.17  0.01  0.369  <0.001  0.214  Initial BW, kg  521.2  522.1  523.2  524.3  21.9  0.202  0.321  0.576  Initial BCS  5.43  5.35  5.27  5.33  0.08  0.124  0.476  0.526  ADG, kg/d  0.83  1.05  0.95  0.89  0.06  0.032  0.042  0.384  G:F, kg/kg  0.163  0.123  0.142  0.151  0.01  0.036  0.123  0.466  Final BW, kg  572.8  586.3  582.0  579.4  23.8  0.041  0.245  0.632  Final BCS  5.62  5.73  5.48  5.54  0.14  0.782  0.110  0.716  BW gain, kg  51.6  64.8  58.8  55.1  3.4  0.032  0.042  0.384  Change in BCS  0.19  0.38  0.21  0.21  0.10  0.417  0.114  0.982    Treatments1    Contrasts3  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM2  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  DM intake, kg/d  8.23  8.32  8.18  8.17  0.01  0.369  <0.001  0.214  Initial BW, kg  521.2  522.1  523.2  524.3  21.9  0.202  0.321  0.576  Initial BCS  5.43  5.35  5.27  5.33  0.08  0.124  0.476  0.526  ADG, kg/d  0.83  1.05  0.95  0.89  0.06  0.032  0.042  0.384  G:F, kg/kg  0.163  0.123  0.142  0.151  0.01  0.036  0.123  0.466  Final BW, kg  572.8  586.3  582.0  579.4  23.8  0.041  0.245  0.632  Final BCS  5.62  5.73  5.48  5.54  0.14  0.782  0.110  0.716  BW gain, kg  51.6  64.8  58.8  55.1  3.4  0.032  0.042  0.384  Change in BCS  0.19  0.38  0.21  0.21  0.10  0.417  0.114  0.982  1CON = control; CO-EN = 75% chopped whole plant corn (WC) co-ensiled with 25% corn modified wet distillers grain (MWDGS) on a DM basis; CS+WDG = corn silage with MWDGS added at feeding time; CS+DDG = corn silage with corn dry distillers grain added at feeding time. Corn silage and WC contained 35% DM, 9.1% CP, and 40% NDF (DM basis). Corn modified wet distillers grain plus solubles contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 2The greatest SEM is presented (n = 24). 3Probabilities for preplanned orthogonal contrasts between CON vs. distillers grain diets, CO-EN vs. diets with distillers grain added at feeding time, and CS+WDG vs. CS+DDG, respectively. View Large Table 3. Effects of corn modified wet distillers grain plus solubles co-ensiled with whole plant chopped corn on growth performance of pregnant heifers (Exp. 1)   Treatments1    Contrasts3  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM2  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  DM intake, kg/d  8.23  8.32  8.18  8.17  0.01  0.369  <0.001  0.214  Initial BW, kg  521.2  522.1  523.2  524.3  21.9  0.202  0.321  0.576  Initial BCS  5.43  5.35  5.27  5.33  0.08  0.124  0.476  0.526  ADG, kg/d  0.83  1.05  0.95  0.89  0.06  0.032  0.042  0.384  G:F, kg/kg  0.163  0.123  0.142  0.151  0.01  0.036  0.123  0.466  Final BW, kg  572.8  586.3  582.0  579.4  23.8  0.041  0.245  0.632  Final BCS  5.62  5.73  5.48  5.54  0.14  0.782  0.110  0.716  BW gain, kg  51.6  64.8  58.8  55.1  3.4  0.032  0.042  0.384  Change in BCS  0.19  0.38  0.21  0.21  0.10  0.417  0.114  0.982    Treatments1    Contrasts3  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM2  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  DM intake, kg/d  8.23  8.32  8.18  8.17  0.01  0.369  <0.001  0.214  Initial BW, kg  521.2  522.1  523.2  524.3  21.9  0.202  0.321  0.576  Initial BCS  5.43  5.35  5.27  5.33  0.08  0.124  0.476  0.526  ADG, kg/d  0.83  1.05  0.95  0.89  0.06  0.032  0.042  0.384  G:F, kg/kg  0.163  0.123  0.142  0.151  0.01  0.036  0.123  0.466  Final BW, kg  572.8  586.3  582.0  579.4  23.8  0.041  0.245  0.632  Final BCS  5.62  5.73  5.48  5.54  0.14  0.782  0.110  0.716  BW gain, kg  51.6  64.8  58.8  55.1  3.4  0.032  0.042  0.384  Change in BCS  0.19  0.38  0.21  0.21  0.10  0.417  0.114  0.982  1CON = control; CO-EN = 75% chopped whole plant corn (WC) co-ensiled with 25% corn modified wet distillers grain (MWDGS) on a DM basis; CS+WDG = corn silage with MWDGS added at feeding time; CS+DDG = corn silage with corn dry distillers grain added at feeding time. Corn silage and WC contained 35% DM, 9.1% CP, and 40% NDF (DM basis). Corn modified wet distillers grain plus solubles contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 2The greatest SEM is presented (n = 24). 3Probabilities for preplanned orthogonal contrasts between CON vs. distillers grain diets, CO-EN vs. diets with distillers grain added at feeding time, and CS+WDG vs. CS+DDG, respectively. View Large Experiment 2 No differences in intake, diet digestibility (Table 4), or fermentation characteristics (Table 5) were found when comparing the CON treatment to DGD or when comparing CS+WDG to CS+DDG. However, when comparing CO-EN to MIX, CO-EN resulted in decreased DMI (P = 0.05) and consequently reduced OM (P = 0.05), N (P = 0.04), and NDF (P = 0.02) intakes. Table 4. Intake, apparent total-tract digestibility, N flow and ruminal fluid dilution rate of finishing steers fed corn modified wet distillers grain plus solubles co-ensiled with chopped whole plant corn (Exp. 2)   Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  Intake, g/d      DM  6,487  5,914  6,855  6,817  536  0.910  0.049  0.933      OM  6,137  5,606  6,494  6,454  501  0.891  0.050  0.926      N  130.4  127.0  148.4  148.4  10.3  0.193  0.035  0.994      NDF  2,123  1,914  2,456  2,412  196  0.388  0.016  0.815  Digestibility,4 %      DM  67.1  70.8  66.0  66.7  3.7  0.858  0.310  0.882      OM  67.8  67.7  72.4  67.3  3.8  0.725  0.603  0.301      N  65.7  72.5  66.5  68.1  4.0  0.388  0.225  0.721      NDF  39.8  46.9  44.3  42.3  5.2  0.479  0.600  0.807  N flow, g/d      Fecal  44.2  35.1  49.8  46.3  4.6  0.925  0.037  0.561      Urine  40.8  45.3  44.5  43.4  15.4  0.749  0.905  0.934      BUN,5 mg/dL  10.3  10.9  10.2  11.8  1.2  0.325  0.894  0.099      Retained N, g/d  45.3  46.6  54.1  58.7  17.6  0.636  0.575  0.822      Fecal DM output, g/d  2,094  1,740  2,338  2,228  206  0.971  0.057  0.693      Fecal OM output, g/d  1,935  1,816  1,802  2,068  229  0.845  0.589  0.313    Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  Intake, g/d      DM  6,487  5,914  6,855  6,817  536  0.910  0.049  0.933      OM  6,137  5,606  6,494  6,454  501  0.891  0.050  0.926      N  130.4  127.0  148.4  148.4  10.3  0.193  0.035  0.994      NDF  2,123  1,914  2,456  2,412  196  0.388  0.016  0.815  Digestibility,4 %      DM  67.1  70.8  66.0  66.7  3.7  0.858  0.310  0.882      OM  67.8  67.7  72.4  67.3  3.8  0.725  0.603  0.301      N  65.7  72.5  66.5  68.1  4.0  0.388  0.225  0.721      NDF  39.8  46.9  44.3  42.3  5.2  0.479  0.600  0.807  N flow, g/d      Fecal  44.2  35.1  49.8  46.3  4.6  0.925  0.037  0.561      Urine  40.8  45.3  44.5  43.4  15.4  0.749  0.905  0.934      BUN,5 mg/dL  10.3  10.9  10.2  11.8  1.2  0.325  0.894  0.099      Retained N, g/d  45.3  46.6  54.1  58.7  17.6  0.636  0.575  0.822      Fecal DM output, g/d  2,094  1,740  2,338  2,228  206  0.971  0.057  0.693      Fecal OM output, g/d  1,935  1,816  1,802  2,068  229  0.845  0.589  0.313  1CON = control; CO-EN = 75% chopped whole plant corn (WC) co-ensiled with 25% corn modified wet distillers grain (MWDGS) on a DM basis; CS+WDG = corn silage with MWDGS added at feeding time; CS+DDG = corn silage with corn dry distillers grain added at feeding time. Corn silage and WC contained 35% DM, 9.1% CP, and 40% NDF (DM basis). Corn modified wet distillers grain plus solubles contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 2Probabilities for preplanned orthogonal contrasts between CON vs. distillers grain diets, CO-EN vs. diets with distillers grain added at feeding time, and CS+WDG vs. CS+DDG, respectively. 3The greatest SEM is presented (n = 4). 4Apparent total tract digestibility. 5BUN = blood urea nitrogen. View Large Table 4. Intake, apparent total-tract digestibility, N flow and ruminal fluid dilution rate of finishing steers fed corn modified wet distillers grain plus solubles co-ensiled with chopped whole plant corn (Exp. 2)   Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  Intake, g/d      DM  6,487  5,914  6,855  6,817  536  0.910  0.049  0.933      OM  6,137  5,606  6,494  6,454  501  0.891  0.050  0.926      N  130.4  127.0  148.4  148.4  10.3  0.193  0.035  0.994      NDF  2,123  1,914  2,456  2,412  196  0.388  0.016  0.815  Digestibility,4 %      DM  67.1  70.8  66.0  66.7  3.7  0.858  0.310  0.882      OM  67.8  67.7  72.4  67.3  3.8  0.725  0.603  0.301      N  65.7  72.5  66.5  68.1  4.0  0.388  0.225  0.721      NDF  39.8  46.9  44.3  42.3  5.2  0.479  0.600  0.807  N flow, g/d      Fecal  44.2  35.1  49.8  46.3  4.6  0.925  0.037  0.561      Urine  40.8  45.3  44.5  43.4  15.4  0.749  0.905  0.934      BUN,5 mg/dL  10.3  10.9  10.2  11.8  1.2  0.325  0.894  0.099      Retained N, g/d  45.3  46.6  54.1  58.7  17.6  0.636  0.575  0.822      Fecal DM output, g/d  2,094  1,740  2,338  2,228  206  0.971  0.057  0.693      Fecal OM output, g/d  1,935  1,816  1,802  2,068  229  0.845  0.589  0.313    Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3, and 4  2 vs. 3 and 4  3 vs. 4  Intake, g/d      DM  6,487  5,914  6,855  6,817  536  0.910  0.049  0.933      OM  6,137  5,606  6,494  6,454  501  0.891  0.050  0.926      N  130.4  127.0  148.4  148.4  10.3  0.193  0.035  0.994      NDF  2,123  1,914  2,456  2,412  196  0.388  0.016  0.815  Digestibility,4 %      DM  67.1  70.8  66.0  66.7  3.7  0.858  0.310  0.882      OM  67.8  67.7  72.4  67.3  3.8  0.725  0.603  0.301      N  65.7  72.5  66.5  68.1  4.0  0.388  0.225  0.721      NDF  39.8  46.9  44.3  42.3  5.2  0.479  0.600  0.807  N flow, g/d      Fecal  44.2  35.1  49.8  46.3  4.6  0.925  0.037  0.561      Urine  40.8  45.3  44.5  43.4  15.4  0.749  0.905  0.934      BUN,5 mg/dL  10.3  10.9  10.2  11.8  1.2  0.325  0.894  0.099      Retained N, g/d  45.3  46.6  54.1  58.7  17.6  0.636  0.575  0.822      Fecal DM output, g/d  2,094  1,740  2,338  2,228  206  0.971  0.057  0.693      Fecal OM output, g/d  1,935  1,816  1,802  2,068  229  0.845  0.589  0.313  1CON = control; CO-EN = 75% chopped whole plant corn (WC) co-ensiled with 25% corn modified wet distillers grain (MWDGS) on a DM basis; CS+WDG = corn silage with MWDGS added at feeding time; CS+DDG = corn silage with corn dry distillers grain added at feeding time. Corn silage and WC contained 35% DM, 9.1% CP, and 40% NDF (DM basis). Corn modified wet distillers grain plus solubles contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 2Probabilities for preplanned orthogonal contrasts between CON vs. distillers grain diets, CO-EN vs. diets with distillers grain added at feeding time, and CS+WDG vs. CS+DDG, respectively. 3The greatest SEM is presented (n = 4). 4Apparent total tract digestibility. 5BUN = blood urea nitrogen. View Large Table 5. Ruminal pH, ammonia, and VFA concentrations of fistulated steers fed chopped whole plant corn co-ensiled with corn modified wet distillers grain plus solubles   Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3 and 4  2 vs. 3 and 4  3 vs. 4  Ruminal pH  6.37  6.44  6.33  6.50  0.15  0.514  0.715  0.140  Ruminal NH3,4 mg/dL  3.52  4.20  6.80  4.09  3.14  0.426  0.532  0.257  Total VFA, mM  93.0  80.9  99.0  94.1  9.0  0.749  0.024  0.449  Ruminal VFA  mol/100 mol          Acetate  63.5  61.9  59.9  59.3  2.1  0.045  0.129  0.735      Propionate  21.6  21.1  23.2  26.2  1.7  0.097  0.014  0.050      Butyrate  10.7  11.8  12.9  10.0  1.1  0.593  0.840  0.170      Isobutyrate  0.84  0.97  0.74  0.94  0.12  0.515  0.121  0.051      Valerate  1.06  1.65  1.42  1.35  0.15  0.083  0.689  0.531      Isovalerate  2.47  3.04  1.98  2.39  0.47  0.998  0.020  0.245      A:P5  2.96  2.95  2.60  2.31  0.20  0.032  0.009  0.097      Fluid dilution rate, %/h  9.63  8.00  10.33  9.20  1.34  0.582  0.077  0.280    Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3 and 4  2 vs. 3 and 4  3 vs. 4  Ruminal pH  6.37  6.44  6.33  6.50  0.15  0.514  0.715  0.140  Ruminal NH3,4 mg/dL  3.52  4.20  6.80  4.09  3.14  0.426  0.532  0.257  Total VFA, mM  93.0  80.9  99.0  94.1  9.0  0.749  0.024  0.449  Ruminal VFA  mol/100 mol          Acetate  63.5  61.9  59.9  59.3  2.1  0.045  0.129  0.735      Propionate  21.6  21.1  23.2  26.2  1.7  0.097  0.014  0.050      Butyrate  10.7  11.8  12.9  10.0  1.1  0.593  0.840  0.170      Isobutyrate  0.84  0.97  0.74  0.94  0.12  0.515  0.121  0.051      Valerate  1.06  1.65  1.42  1.35  0.15  0.083  0.689  0.531      Isovalerate  2.47  3.04  1.98  2.39  0.47  0.998  0.020  0.245      A:P5  2.96  2.95  2.60  2.31  0.20  0.032  0.009  0.097      Fluid dilution rate, %/h  9.63  8.00  10.33  9.20  1.34  0.582  0.077  0.280  1CON = control; CO-EN = 35% chopped whole plant corn co-ensiled with 65% corn modified wet distillers grain (MWDGS) on a DM basis; CS+WDG = corn silage with MWDGS added at feeding time; CS+DDG = corn silage with corn dry distillers grain added at feeding time. Corn silage and chopped whole plant corn contained 35% DM, 9.1% CP, and 40% NDF (DM basis). Corn modified wet distillers grain plus solubles (MWDGS) contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 2Probabilities for preplanned orthogonal contrasts between CON vs. distillers grain diets, CO-EN vs. diets with distillers grain added at feeding time, and CS+WDG vs. CS+DDG, respectively. 3The greatest SEM is presented (n = 4). 4Ruminal ammonia levels measured 4 h after feeding. 5A:P = acetate:propionate. View Large Table 5. Ruminal pH, ammonia, and VFA concentrations of fistulated steers fed chopped whole plant corn co-ensiled with corn modified wet distillers grain plus solubles   Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3 and 4  2 vs. 3 and 4  3 vs. 4  Ruminal pH  6.37  6.44  6.33  6.50  0.15  0.514  0.715  0.140  Ruminal NH3,4 mg/dL  3.52  4.20  6.80  4.09  3.14  0.426  0.532  0.257  Total VFA, mM  93.0  80.9  99.0  94.1  9.0  0.749  0.024  0.449  Ruminal VFA  mol/100 mol          Acetate  63.5  61.9  59.9  59.3  2.1  0.045  0.129  0.735      Propionate  21.6  21.1  23.2  26.2  1.7  0.097  0.014  0.050      Butyrate  10.7  11.8  12.9  10.0  1.1  0.593  0.840  0.170      Isobutyrate  0.84  0.97  0.74  0.94  0.12  0.515  0.121  0.051      Valerate  1.06  1.65  1.42  1.35  0.15  0.083  0.689  0.531      Isovalerate  2.47  3.04  1.98  2.39  0.47  0.998  0.020  0.245      A:P5  2.96  2.95  2.60  2.31  0.20  0.032  0.009  0.097      Fluid dilution rate, %/h  9.63  8.00  10.33  9.20  1.34  0.582  0.077  0.280    Treatment1    Contrast2  Item  CON (1)  CO-EN (2)  CS+WDG (3)  CS+DDG (4)  SEM3  1 vs. 2, 3 and 4  2 vs. 3 and 4  3 vs. 4  Ruminal pH  6.37  6.44  6.33  6.50  0.15  0.514  0.715  0.140  Ruminal NH3,4 mg/dL  3.52  4.20  6.80  4.09  3.14  0.426  0.532  0.257  Total VFA, mM  93.0  80.9  99.0  94.1  9.0  0.749  0.024  0.449  Ruminal VFA  mol/100 mol          Acetate  63.5  61.9  59.9  59.3  2.1  0.045  0.129  0.735      Propionate  21.6  21.1  23.2  26.2  1.7  0.097  0.014  0.050      Butyrate  10.7  11.8  12.9  10.0  1.1  0.593  0.840  0.170      Isobutyrate  0.84  0.97  0.74  0.94  0.12  0.515  0.121  0.051      Valerate  1.06  1.65  1.42  1.35  0.15  0.083  0.689  0.531      Isovalerate  2.47  3.04  1.98  2.39  0.47  0.998  0.020  0.245      A:P5  2.96  2.95  2.60  2.31  0.20  0.032  0.009  0.097      Fluid dilution rate, %/h  9.63  8.00  10.33  9.20  1.34  0.582  0.077  0.280  1CON = control; CO-EN = 35% chopped whole plant corn co-ensiled with 65% corn modified wet distillers grain (MWDGS) on a DM basis; CS+WDG = corn silage with MWDGS added at feeding time; CS+DDG = corn silage with corn dry distillers grain added at feeding time. Corn silage and chopped whole plant corn contained 35% DM, 9.1% CP, and 40% NDF (DM basis). Corn modified wet distillers grain plus solubles (MWDGS) contained 48% DM, 29% CP, 14.1% crude fat, 31% NDF, 1.48 Mcal/kg, 0.75% sulfur, and 0.87% phosphorous (DM basis). Corn dry distillers grain plus solubles contained 87% DM, 28% crude protein, 13.9% fat, 32% NDF, 1.45 Mcal/kg, 0.74% sulfur, and 0.88% phosphorous (DM basis). 2Probabilities for preplanned orthogonal contrasts between CON vs. distillers grain diets, CO-EN vs. diets with distillers grain added at feeding time, and CS+WDG vs. CS+DDG, respectively. 3The greatest SEM is presented (n = 4). 4Ruminal ammonia levels measured 4 h after feeding. 5A:P = acetate:propionate. View Large There were no differences in apparent total tract DM, OM, N, or NDF digestibility among treatments. Fecal DM output, N flow, retained N, BUN concentrations, and fluid dilution rate were also similar when comparing CON vs. DGD and CS+DDG vs. CS+WDG. However, when comparing CO-EN to MIX, N fecal flow was less (P = 0.04) and fecal DM output tended to be less (P = 0.06) when steers were fed CO-EN, in accordance with the lower DMI mentioned earlier. As expected, no differences were detected in NH3 concentrations between treatments because diets were formulated to have similar levels of CP. Average ruminal fluid pH was also similar across treatments and was maintained above 6.3 during the length of the sample collection period. Total VFA concentrations were similar across treatments, consistent with ruminal fluid pH data, except when comparing CO-EN to MIX, in which case CO-EN resulted in decreased total VFA concentration (P = 0.02), decreased propionate (P = 0.01), and greater isovalerate (P = 0.02). Also, there was a greater molar proportion of acetate in the rumen (P = 0.05) and a greater acetate:proprionate (P = 0.03) for the CON diet compared with DGD. Differences observed between CO-EN and MIX on total ruminal VFA concentration and profile of VFA may be due to changes to the MWDGS in the co-ensiled product during the fermentation process. However, these changes appear to be of little biological significance when contrasted with results in Exp. 1. Overall, results presented are in agreement with previous research conducted by Peter et al. (2000) who reported no overall effect on nutrient digestion or fermentation characteristics when beef steers were fed up to 20% DGS of DM in diets, compared with those fed corn-based diets. Similarly, Mateo et al. (2004) reported no differences in apparent total tract digestibility of DM, OM, N, or NDF when steers were fed 0, 20, or 40% DDGS replacing soybean meal and cracked corn in 90% concentrate finishing diets. Leupp et al. (2009) concluded that replacing dry-rolled corn with up to 60% DDGS in 70% concentrate diets resulted in no adverse effects in OM total tract digestion of beef cattle. Vander Pol et al. (2009), on a direct comparison between 40% WDGS (DM basis) and a dry-rolled corn based control diet, reported no differences in average pH or total tract DM digestibility when fed to fistulated Holstein steers. Data from these studies suggest that MWDGS can be successfully co-ensiled with WC, preserving the quality of the forage and DGS included in the mix, resulting in similar growth performance, diet digestibility, and intake characteristics compared with traditional corn-based diets supplemented with soybean meal and corn silage diets supplemented with DGS. This preservation practice provides cattlemen the means to improve flexibility in the use of WDGS when economically feasible. LITERATURE CITED Anderson J. L. Kalscheur K. F. Garcia A. D. Schingoethe D. J. Hippen A. R. 2009. Ensiling characteristics of wet distillers grains mixed with soybean hulls and evaluation of the feeding value for growing Holstein heifers. J. Anim. Sci.  87: 2113– 2123. Google Scholar CrossRef Search ADS PubMed  Association of Official Analytical Chemists (AOAC) 1990. Official Methods of Analysis. 15th ed. AOAC, Arlington, VA. Buckmaster D. R. Gunn P. G. Lake S. L. Lemenager R. P. Claeys M. C. 2008. Co-ensiling of wet distiller's grains. Presentation no. 083645. American Society of Agricultural and Biological Engineers Meeting, Providence, RI. Dooley F. J. Cox M. Cox L. 2008. Distillers grain handbook: A guide for Indiana producers to using DDGS for animal feed. A report for the Indiana Corn Marketing Council. http://incorn.org/index.php?option=com_content&task=view&id=43. Accessed Feb. 10, 2010. Engel C. L. Patterson H. H. Perry G. A. Haigh R. Johnson J. 2005. Evaluation of dried distillers grains with solubles as a feedstuff for heifers in the last trimester of gestation. 2005 Beef Research Report. BEEF 2005–14. South Dakota State University, Brookings. Erickson G. E. Klopfenstein T. J. Rasby R. J. Stalker L. A. Plugge B. L. Bauer D. E. Mark D. R. 2008. Storage of wet corn co-products. Manual, University of Nebraska, Lincoln, http://beef.unl.eduhttp://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1530&context=animalscifacpu. Accessed Nov. 24, 2009. Ferrell C. L. Garrett W. N. Hinman N. 1976. Growth, development and composition of the udder and gravid uterus of beef heifers during pregnancy. J. Anim. Sci.  42: 1477– 1489. Google Scholar CrossRef Search ADS PubMed  Goetsch A. L. Galyean M. L. 1983. Influence of feeding 413 frequency on passage of fluid and particulate markers in steers fed a concentrate diet. Can. J. Anim. Sci.  63: 727– 730. Google Scholar CrossRef Search ADS   Gunn P. G. 2008. Bio-fuel byproducts in ruminant nutrition. MS diss., Purdue University, West Lafayette, IN. Johnson C. O. L. E. Huber J. T. King K. J. 1987. Storage and utilization of brewers wet grains in diets for lactating dairy cows. J. Dairy Sci.  70: 98– 107. Google Scholar CrossRef Search ADS   Kalscheur K. F. Garcia A. D. Hippen A. R. Schingoethe D. J. 2004. Fermentation characteristics of ensiling wet corn distillers grains in combination with beet pulp. J. Dairy Sci..  87( Suppl. 1): 53 (Abstr.). Google Scholar PubMed  Lake S. L. Scholljegerdes E. J. Atkinson R. L. Nayigihugu V. Paisley S. I. Rule D. C. Moss G. E. Robinson T. J. Hess B. W. 2005. Body condition score at parturition and postpartum supplemental fat effects on cow and calf performance. J. Anim. Sci.  83: 2908– 2917. Google Scholar CrossRef Search ADS PubMed  Lemenager R. P. Applegate T. Donkin S. Johnson T. Lake S. Neary M. Radcliffe S. Richert B. Schinckel A. Schutz M. Sutton A. 2006. The value of distillers' grains as a livestock feed. Purdue University Cooperative Extension Service, West Lafayette, IN. Leupp J. L. Lardy G. P. Karges K. K. Gibson M. L. Caton J. S. 2009. Effects of increasing level of corn distillers dried grains with solubles on intake, digestion, and ruminal fermentation in steers fed seventy percent concentrate diets. J. Anim. Sci.  87: 2906– 2912. Google Scholar CrossRef Search ADS PubMed  Marsh W. B. Fingernut B. Kitsch E. 1957. Determination of urea nitrogen with the diacetyl method and an automatic dialyzing apparatus. Am. J. Clin. Pathol.  28: 681. Google Scholar CrossRef Search ADS PubMed  Martin J. L. Cupp A. S. Rasby R. J. Hall Z. C. Funston R. N. 2007. Utilization of dried distillers grains for developing beef heifers. J. Anim. Sci.  85: 2298– 2303. Google Scholar CrossRef Search ADS PubMed  Mateo K. S. Tjardes K. E. Wright C. L. Koger T. J. Rops B. D. 2004. Evaluation of feeding varying levels of wet distillers grains with solubles as compared to dry distillers grains with solubles to finishing steers. South Dakota Beef Cattle Report. BEEF 2004–03. South Dakota State Univ., Brookings, SD. p. 14– 19. Muck R. E. 2004. Effects of corn silage inoculants on aerobic stability. Trans. ASAE  47( 4): 1011– 1016. Google Scholar CrossRef Search ADS   NRC 2000. Nutrient requirements of beef cattle. 7th ed. National Academy Press, Washington, DC. Peter C. M. Faulkner D. B. Merchen N. R. Parrett D. F. Nash T. G. Dahlquist J. M. 2000. The effects of corn milling co products on growth performance and diet digestibility by beef cattle. J. Anim. Sci.  78: 1– 6. Google Scholar CrossRef Search ADS PubMed  Stalker L. A. Adams D. C. Klopfenstein T. J. 2006. A system for wintering beef heifers using dried distillers grains. 2006 Nebraska Beef Report. University of Nebraska-Lincoln Extension, Lincoln, NE. Uden P. Colucci P. E. Van Soest P. J. 1980. Investigations of chromium, cerium, cobalt as markers in digesta. Rate of passage studies. J. Sci. Food Agric.  31: 625– 632. Google Scholar CrossRef Search ADS PubMed  Van Soest P. J. 1994 Nutritional ecology of the ruminant. 2nd ed. Cornell Univ. Press, Ithaca, NY. Vander Pol K. J. Luebbe M. K. Crawford G. I. Erickson G. E. Klopfenstein T. J. 2009. Performance and digestibility characteristics of finishing diets containing distillers grains, composites of corn processing co-products, or supplemental corn oil. J. Anim. Sci.  87: 639– 652. Google Scholar CrossRef Search ADS PubMed  Vasconcelos J. T. Galyean M. L. 2007. Nutritional recommendations of feedlot consulting nutritionists: The 2007 Texas Tech University survey. J. Anim. Sci.  85: 2772. Google Scholar CrossRef Search ADS PubMed  Footnotes 1 This project was funded in part by the USDA National Research Initiative, the Indiana State Department of Agriculture, and the Purdue College of Agriculture. American Society of Animal Science
TI - Effects of feeding corn modified wet distillers grain plus solubles co-ensiled with chopped whole plant corn on heifer growth performance and diet digestibility in beef cattle
JF - Journal of Animal Science
DO - 10.2527/jas.2012-5777
DA - 2013-09-01
UR - https://www.deepdyve.com/lp/oxford-university-press/effects-of-feeding-corn-modified-wet-distillers-grain-plus-solubles-co-khUh67LGjI
SP - 4366
EP - 4373
VL - 91
IS - 9
DP - DeepDyve
ER -