TY - JOUR
AU - Hodgen, J. M.
AB - ABSTRACT The objective of this study was to quantify the effects of zilpaterol hydrochloride (ZH) on feeding performance and fabrication yield of concentrate-finished cull cows. Three hundred twenty commercial cull cows (2 to 10 yr old) were obtained from ranches in Missouri and South Dakota and assigned to 1 of 2 treatments: 1) a control diet containing no ZH and 2) a diet that contained ZH. Cows were fed for 75, 88, or 110 d, and all received the control ration until ZH treatments were initiated. Twenty-four days before slaughter, ZH feeding began for the designated treatment pens; cows were fed ZH [8.33 mg/kg (100% DM basis)] for 20 d with a 4-d withdrawal period before slaughter. No differences (P > 0.05) were detected between the 2 treatment groups for initial BW or DMI. Final BW (640.5 vs. 619.1 kg), ADG for the last 24 d (2.75 vs. 2.17 kg), and G:F for the last 24 d (0.160 vs. 0.126) were greater (P < 0.01) in cows fed ZH than the control cows. No differences (P > 0.05) were found for lean or skeletal maturity score, fat thickness, LM area, HCW, or calculated yield grade among the 2 treatment groups. Feeding ZH increased (P < 0.01) HCW (390.1 vs. 369.2 kg), dressed carcass yield (61.01 vs. 59.45%), and LM area (93.3 vs. 86.5 cm2) and decreased (P < 0.01) marbling score (Slight63 vs. Slight86) compared with control cows. Cows fed ZH had greater (P < 0.05) primal weights for chuck (mock) tender (2.63 vs. 2.28 kg), lip-on rib eye roll (13.54 vs. 12.56 kg), top sirloin butt (12.74 vs. 11.82 kg), top (inside) round (14.58 vs. 12.89 kg), and peeled knuckle (12.87 vs. 11.51 kg) while yielding a decreased percentage of mechanical knife trimmings (1.15 vs. 1.35%; P < 0.01) and more top (inside) rounds (3.71 vs. 3.46%; P = 0.02) than the control cows. No differences (P > 0.07) were found for the remaining fabrication yield attributes. The ZH-treated cows had greater (P < 0.05) fabrication dollar values for chuck (mock) tender (8.82 vs. 7.66 $/carcass), lip-on rib eye roll (64.20 vs. 59.56 $/carcass), strip loin (0 × 1; 49.13 vs. 44.75 $/carcass), top sirloin butt (35.60 vs. 33.01 $/carcass), bottom round (flat; 44.23 vs. 39.23 $/carcass), top (inside) round (60.30 vs. 53.33 $/carcass), knuckle (peeled; 44.26 vs. 39.57 $/carcass), and total salable yield (879.50 vs. 803.70 $/carcass) than control cows. These results suggest the feeding of ZH to concentrate-finished cull cows enhances production efficiencies and can add new value to the cull cow market. INTRODUCTION The use of β-adrenergic agonists (βAA) to improve the efficiency of animal production has been of interest to researchers for more than 20 yr. β-Agonists generally cause an increase in protein synthesis, a decrease in protein degradation, or some combination of both (Mersmann, 1998). In addition, βAA can decrease lipogenesis and increase lipolysis (Dunshea et al., 1993; McNeel and Mersmann, 1995). Zilpaterol hydrochloride (ZH; Intervet, Millsboro, DE) is a synthetic βAA approved for use in cattle, fed in confinement for slaughter, in the United States. Zilpaterol hydrochloride is labeled to increase BW gain, improve feed efficiency, and increase carcass leanness (FDA, 2006). Previous research has shown that steers fed ZH had increased carcass weight, dressed carcass yield, and LM area, and decreased 12th-rib subcutaneous fat thickness compared with steers not fed ZH (Plascencia et al., 1999; Vasconcelos et al., 2008; Elam et al., 2009). Boler et al. (2009) and Hilton et al. (2010) illustrated that ZH was effective in increasing boxed beef yield when included in the diet of calf-fed Holstein and native steers for at least 20 d before slaughter. Previous reports of feeding ZH to cull cows observed increased absolute weights of round subprimals (Neill et al., 2009) and increased percentage of subprimal chuck-rib-loin-round yields (Lowe et al., 2010). However, previous reports did not quantify the value associated with feeding ZH to cull cows on boxed beef value. Therefore, the objective of this study was to determine the effects that ZH had on feeding performance, carcass grading performance, and fabrication yield and value of concentrate-finished cull cows. MATERIALS AND METHODS The feeding portion of this experiment was conducted at Agri-Research Center Inc. (Canyon, TX). All experimental procedures followed the guidelines described in the Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching (FASS, 1999). Treatment Allocation Three hundred twenty nonpregnant commercial cull cows were obtained from ranches in Missouri and South Dakota. Cows were blocked by ranch source (Missouri or South Dakota) and age (2 to 3 yr; 3 to 5 yr; 5 to 10 yr) to treatments and pens, resulting in 16 blocks. Within each ranch source and age, the selected animals were stratified by BW (heaviest to lightest) and then were randomly selected from the ranked BW and assigned to pens until all pens were full (10 animals/pen) for each ranch source and age. All cows within the same pen received the same treatment. The 2 treatments consisted of 1) a control diet containing no ZH and 2) a diet that contained ZH. Feeding Management All cows included in the study received Safeguard 10% Oral Suspension (Intervet Inc.), Ivomec Pour-On (Merial, Duluth, GA), and a growth-promoting implant containing 200 mg of trenbolone acetate and 20 mg of estradiol (Revalor-200, Intervet Inc.) according to the manufacturer's instructions. Throughout the entire treatment period, the cows were observed at least once per day by trained personnel. The cows were housed in dirt-floor pens with adequate pen and bunk space and were exposed to ambient environmental conditions. Cows were slaughtered in 3 groups that were on feed for 75, 88, and 110 d. Cows were given ad libitum access to feed and water; all cows were fed the control ration until ZH treatments were initiated. The composition of the control and ZH diet is provided in Table 1. Twenty-four days before slaughter, ZH feeding began for the designated treatment pens. The cows were fed ZH at 8.33 mg/kg (100% DM basis) for 20 d with a 4-d withdrawal period before slaughter. After the 4-d withdrawal period had been completed, the cows were individually weighed and a final BW was recorded. All the cows were then sent to a commercial slaughter facility to be humanely slaughtered and processed. Table 1. Composition and analyzed nutrient content of diets Item  Diet  Control  Zilpaterol1  Ingredient,2 %         Flaked corn  57.0  57.0   Corn gluten feed  8.5  8.5   Alfalfa hay  14.0  14.0   Cottonseed hulls  9.0  9.0   Molasses blend  5.0  5.0   Fat  1.0  1.0   Microingredient3  1.0  1.0   Supplement4  4.5  4.5  Chemical composition,5 %         DM  81.40  81.40   CP  13.85  13.85   Ca  0.78  0.78   P  0.39  0.39   NPN  2.55  2.55  Item  Diet  Control  Zilpaterol1  Ingredient,2 %         Flaked corn  57.0  57.0   Corn gluten feed  8.5  8.5   Alfalfa hay  14.0  14.0   Cottonseed hulls  9.0  9.0   Molasses blend  5.0  5.0   Fat  1.0  1.0   Microingredient3  1.0  1.0   Supplement4  4.5  4.5  Chemical composition,5 %         DM  81.40  81.40   CP  13.85  13.85   Ca  0.78  0.78   P  0.39  0.39   NPN  2.55  2.55  1Zilpaterol hydrochloride (Zilmax, Intervet/Schering-Plough Animal Health, Millsboro, DE). 2As-fed basis. 3Microingredients added to the diet using a micro-weigh machine (Micro Beef Technologies, Amarillo, TX) included Rumensin [Elanco (Indianapolis, IN), 250 mg/(animal·d)] and Tylan [Elanco, 90 mg/(animal·d)]. The Zilmax diet contained zilpaterol hydrochloride at a concentration of 8.33 mg/kg of dietary DM. 4Supplement composition, in descending order, consisted of cottonseed meal, calcium carbonate, urea, rice mill by-product, salt, ammonium sulfate, potassium chloride, and trace minerals. In addition, vitamins were included to provide 40,000 IU of vitamin A/kg, 400 IU of vitamin D/kg, and 40 IU of vitamin E/kg of the final diet (DM basis). 5DM basis. View Large Table 1. Composition and analyzed nutrient content of diets Item  Diet  Control  Zilpaterol1  Ingredient,2 %         Flaked corn  57.0  57.0   Corn gluten feed  8.5  8.5   Alfalfa hay  14.0  14.0   Cottonseed hulls  9.0  9.0   Molasses blend  5.0  5.0   Fat  1.0  1.0   Microingredient3  1.0  1.0   Supplement4  4.5  4.5  Chemical composition,5 %         DM  81.40  81.40   CP  13.85  13.85   Ca  0.78  0.78   P  0.39  0.39   NPN  2.55  2.55  Item  Diet  Control  Zilpaterol1  Ingredient,2 %         Flaked corn  57.0  57.0   Corn gluten feed  8.5  8.5   Alfalfa hay  14.0  14.0   Cottonseed hulls  9.0  9.0   Molasses blend  5.0  5.0   Fat  1.0  1.0   Microingredient3  1.0  1.0   Supplement4  4.5  4.5  Chemical composition,5 %         DM  81.40  81.40   CP  13.85  13.85   Ca  0.78  0.78   P  0.39  0.39   NPN  2.55  2.55  1Zilpaterol hydrochloride (Zilmax, Intervet/Schering-Plough Animal Health, Millsboro, DE). 2As-fed basis. 3Microingredients added to the diet using a micro-weigh machine (Micro Beef Technologies, Amarillo, TX) included Rumensin [Elanco (Indianapolis, IN), 250 mg/(animal·d)] and Tylan [Elanco, 90 mg/(animal·d)]. The Zilmax diet contained zilpaterol hydrochloride at a concentration of 8.33 mg/kg of dietary DM. 4Supplement composition, in descending order, consisted of cottonseed meal, calcium carbonate, urea, rice mill by-product, salt, ammonium sulfate, potassium chloride, and trace minerals. In addition, vitamins were included to provide 40,000 IU of vitamin A/kg, 400 IU of vitamin D/kg, and 40 IU of vitamin E/kg of the final diet (DM basis). 5DM basis. View Large Carcass Evaluation At slaughter, HCW was recorded. Twenty-four hours postslaughter, detailed carcass evaluation was conducted by personnel from the Beef Carcass Research Center (West Texas A&M University, Canyon), which included marbling score evaluated on a 90-point scale (slight90 denoted as 39; small00 denoted as 40), lean and skeletal maturity evaluated on a 50-point scale (B30 denoted as 130; C40 denoted as 240), 12th-rib subcutaneous fat thickness, and LM area. A final quality grade and calculated yield grade for each carcass were also determined (USDA, 1997). Fabrication Yield Each carcass was fabricated into subprimal cuts according to guidelines of the North American Meat Processors (NAMP) Association (NAMP, 2006). The mock tender (NAMP #116B) and short rib (NAMP #130A) were removed from the primal chuck. The rib-eye roll, lip-on (2 × 2; NAMP #112A), inside skirt (NAMP #121D), and outside skirt (NAMP #121C) were removed from the primal rib/plate. The peeled tender, side muscle off (NAMP #190), boneless strip loin (0 × 1; NAMP #180), top sirloin butt (NAMP #184), bottom sirloin tri-tip (NAMP #185D), boneless bottom sirloin flap (NAMP #185A), and flank steak (NAMP #193) were removed from the primal loin/flank. The top (inside) round (NAMP #169A), knuckle (peeled; NAMP #167A), 100% lean bottom round (flat; NAMP #171B), and 100% lean eye of round (NAMP #171C) were removed from the primal round. Each subprimal was weighed and recorded to calculate a percentage of the chilled carcass weight and subprimal value. Fabrication Value Determination Subprimals (LM_XB405) and boneless beef trimmings (LM_XB401) were valued using weighted national USDA Market News reports for breaker/boner cows on October 9, 2009 (USDA, 2009a,b). Value of each subprimal or trimming component was calculated as the product of the group subprimal or trimming component weight and the wholesale subprimal value, which was then divided by total number of carcasses within group to determine value per carcass. Statistical Analysis Feeding performance and carcass characteristic data were analyzed using the GLM procedure (SAS Inst. Inc., Cary, NC). Pen (n = 32) was the experimental unit in a complete block design; the model statement included treatment and block. Means were generated by the LSMEANS option. Fabrication yield and value analyses were analyzed using the TTEST procedure. Due to the requirements of the commercial processor, we were unable to fabricate cull cows by pen; rather, we were required to fabricate an entire treatment within a slaughter group at 1 time. As such, fabrication group (n = 6) was the experimental unit for boxed beef yield and value analyses in a completely randomized design. RESULTS AND DISCUSSION Feeding Performance There were no differences (P > 0.12) found between treatments for initial BW, BW at d 24, or DMI (Table 2). Final BW, ADG for the last 24 d, ADG d 0 to end, G:F for the last 24 d, and G:F from d 0 to end were 2.98, 26.73, 10.30, 30, and 11.28% greater (P < 0.01) for cows fed ZH than control cows. Of particular interest is the dramatic increase in ADG and G:F observed in the last 24 d in response to ZH feeding. These results are similar to or exceed production efficiencies reported by Beckett et al. (2009), Elam et al. (2009), and Neill et al. (2009) and illustrate the increase in nutrient deposition that results with ZH feeding. Table 2. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on feeding performance of concentrate finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  BW               Initial, kg  416.7  415.6  17.3  0.29   d 24, kg  569.4  574.1  9.5  0.12   Final, kg  619.1  640.5  10.2  <0.01  BW gain               Last 24 d, kg  51.7  65.5  2.6  <0.01   d 0 to end, kg  202.4  224.9  10.4  <0.01  ADG               Last 24 d, kg  2.17  2.75  0.12  <0.01   d 0 to end, kg  2.09  2.33  0.04  <0.01  DMI               Last 24 d, kg/d  17.2  17.3  0.3  0.71   d 0 to end, kg/d  15.8  15.8  0.3  0.95  G:F               Last 24 d  0.126  0.160  0.007  <0.01   d 0 to end  0.133  0.148  0.004  <0.01  Item  Days fed zilpaterol  SEM  P-value  0  20  BW               Initial, kg  416.7  415.6  17.3  0.29   d 24, kg  569.4  574.1  9.5  0.12   Final, kg  619.1  640.5  10.2  <0.01  BW gain               Last 24 d, kg  51.7  65.5  2.6  <0.01   d 0 to end, kg  202.4  224.9  10.4  <0.01  ADG               Last 24 d, kg  2.17  2.75  0.12  <0.01   d 0 to end, kg  2.09  2.33  0.04  <0.01  DMI               Last 24 d, kg/d  17.2  17.3  0.3  0.71   d 0 to end, kg/d  15.8  15.8  0.3  0.95  G:F               Last 24 d  0.126  0.160  0.007  <0.01   d 0 to end  0.133  0.148  0.004  <0.01  1Intervet/Schering-Plough Animal Health, Millsboro, DE. View Large Table 2. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on feeding performance of concentrate finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  BW               Initial, kg  416.7  415.6  17.3  0.29   d 24, kg  569.4  574.1  9.5  0.12   Final, kg  619.1  640.5  10.2  <0.01  BW gain               Last 24 d, kg  51.7  65.5  2.6  <0.01   d 0 to end, kg  202.4  224.9  10.4  <0.01  ADG               Last 24 d, kg  2.17  2.75  0.12  <0.01   d 0 to end, kg  2.09  2.33  0.04  <0.01  DMI               Last 24 d, kg/d  17.2  17.3  0.3  0.71   d 0 to end, kg/d  15.8  15.8  0.3  0.95  G:F               Last 24 d  0.126  0.160  0.007  <0.01   d 0 to end  0.133  0.148  0.004  <0.01  Item  Days fed zilpaterol  SEM  P-value  0  20  BW               Initial, kg  416.7  415.6  17.3  0.29   d 24, kg  569.4  574.1  9.5  0.12   Final, kg  619.1  640.5  10.2  <0.01  BW gain               Last 24 d, kg  51.7  65.5  2.6  <0.01   d 0 to end, kg  202.4  224.9  10.4  <0.01  ADG               Last 24 d, kg  2.17  2.75  0.12  <0.01   d 0 to end, kg  2.09  2.33  0.04  <0.01  DMI               Last 24 d, kg/d  17.2  17.3  0.3  0.71   d 0 to end, kg/d  15.8  15.8  0.3  0.95  G:F               Last 24 d  0.126  0.160  0.007  <0.01   d 0 to end  0.133  0.148  0.004  <0.01  1Intervet/Schering-Plough Animal Health, Millsboro, DE. View Large Carcass Characteristics Cows fed ZH for 20 d had HCW that were 20.9 kg heavier (P < 0.01), dressed carcass yields that were 1.56 percentage points greater (P < 0.01), marbling scores that were 23 points less (P < 0.01), and LM areas that were 6.8 cm2 larger (P < 0.01) compared with cows not fed ZH (Table 3). The current study results concur with those of Elam et al. (2009), Neill et al. (2009), Robles-Estrada et al. (2009), and Beckett et al. (2010), who collectively reported increased HCW (4.2 to 13.6 kg), dressed yield (0.5 to 2.0%), and LM area (5.1 to 9.4 cm2) and decreased marbling scores (14 to 28 points). No differences were found between treatments (P ≥ 0.11) for lean maturity score, skeletal maturity score, 12th-rib subcutaneous fat thickness, LM area/HCW, or USDA calculated yield grade. Table 3. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on carcass characteristics of concentrate-finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  HCW, kg  369.2  390.1  5.4  <0.01  Dressed carcass yield, %  59.45  61.01  0.22  <0.01  Marbling score2  38.6  36.3  0.5  <0.01  Lean maturity score3  84.7  91.8  6.5  0.15  Skeletal maturity score3  135.4  137.9  28.4  0.78  Fat thickness, cm  1.39  1.41  0.07  0.66  LM area, cm2  86.5  93.3  1.1  <0.01  LM area/HCW, cm2/100 kg  23.5  24.0  0.4  0.11  USDA calculated yield grade  2.67  2.53  0.12  0.12  Item  Days fed zilpaterol  SEM  P-value  0  20  HCW, kg  369.2  390.1  5.4  <0.01  Dressed carcass yield, %  59.45  61.01  0.22  <0.01  Marbling score2  38.6  36.3  0.5  <0.01  Lean maturity score3  84.7  91.8  6.5  0.15  Skeletal maturity score3  135.4  137.9  28.4  0.78  Fat thickness, cm  1.39  1.41  0.07  0.66  LM area, cm2  86.5  93.3  1.1  <0.01  LM area/HCW, cm2/100 kg  23.5  24.0  0.4  0.11  USDA calculated yield grade  2.67  2.53  0.12  0.12  1Intervet/Schering-Plough Animal Health, Millsboro, DE. 2Scores: 30 = Slight; 40 = Small; 50 = Modest. 3Scores: 0 to 99 = A maturity; 100 to 199 = B maturity; 200 to 299 = C maturity; 300 to 399 = D maturity. View Large Table 3. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on carcass characteristics of concentrate-finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  HCW, kg  369.2  390.1  5.4  <0.01  Dressed carcass yield, %  59.45  61.01  0.22  <0.01  Marbling score2  38.6  36.3  0.5  <0.01  Lean maturity score3  84.7  91.8  6.5  0.15  Skeletal maturity score3  135.4  137.9  28.4  0.78  Fat thickness, cm  1.39  1.41  0.07  0.66  LM area, cm2  86.5  93.3  1.1  <0.01  LM area/HCW, cm2/100 kg  23.5  24.0  0.4  0.11  USDA calculated yield grade  2.67  2.53  0.12  0.12  Item  Days fed zilpaterol  SEM  P-value  0  20  HCW, kg  369.2  390.1  5.4  <0.01  Dressed carcass yield, %  59.45  61.01  0.22  <0.01  Marbling score2  38.6  36.3  0.5  <0.01  Lean maturity score3  84.7  91.8  6.5  0.15  Skeletal maturity score3  135.4  137.9  28.4  0.78  Fat thickness, cm  1.39  1.41  0.07  0.66  LM area, cm2  86.5  93.3  1.1  <0.01  LM area/HCW, cm2/100 kg  23.5  24.0  0.4  0.11  USDA calculated yield grade  2.67  2.53  0.12  0.12  1Intervet/Schering-Plough Animal Health, Millsboro, DE. 2Scores: 30 = Slight; 40 = Small; 50 = Modest. 3Scores: 0 to 99 = A maturity; 100 to 199 = B maturity; 200 to 299 = C maturity; 300 to 399 = D maturity. View Large Fabrication Yield Cull cows fed ZH for 20 d yielded a greater (P < 0.05) weight for chuck (mock) tender (2.63 vs. 2.28 kg), lip-on rib-eye roll (13.54 vs. 12.56 kg), top sirloin butt (12.74 vs. 11.82 kg), top (inside) round (14.58 vs. 12.89 kg), and peeled knuckle (12.87 vs. 11.51 kg) than cows that did not receive ZH (Table 4). Additionally, numerically greater values for strip loin (14.06 vs. 12.81 kg; P = 0.10), and bottom round (flat) and eye of round (12.23 vs. 10.85 kg; P = 0.06) were observed from cows fed ZH. These data support the findings reported by Boler et al. (2009), Neill et al. (2009), and Hilton et al. (2010), which indicate an increase in primal weights throughout the carcass, but more profound in the round. Table 4. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on fabrication yield of concentrate-finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  Cold carcass side weight (CSW), kg  373.0  393.0  9.6  0.22  Lean trimmings, kg  195.5  204.4  5.9  0.35   % CSW  52.39  51.99  0.44  0.55  Mechanical knife trimmings, kg  5.02  4.54  0.17  0.12   % CSW  1.35  1.15  0.03  <0.01  SPB,2 kg  5.81  6.56  0.39  0.25   % CSW  1.56  1.67  0.06  0.28  Chuck (mock) tender, kg  2.28  2.63  0.06  0.02   % CSW  0.61  0.67  0.02  0.14  Chuck short rib, kg  4.44  4.47  0.08  0.78   % CSW  1.19  1.14  0.02  0.08  Rib eye roll, lip on (2 × 2), kg  12.56  13.54  0.08  <0.01   % CSW  3.37  3.45  0.07  0.49  Peeled tender, side muscle on, kg  5.70  6.17  0.21  0.20   % CSW  1.53  1.57  0.08  0.73  Strip loin (0 × 1), kg  12.81  14.06  0.40  0.10   % CSW  3.44  3.58  0.05  0.11  Top sirloin butt, kg  11.82  12.74  0.16  0.03   % CSW  3.17  3.24  0.05  0.31  Bottom sirloin tri-tip, kg  2.33  2.47  0.22  0.68   % CSW  0.62  0.63  0.05  0.92  Bottom sirloin flap, kg  2.70  2.47  0.17  0.39   % CSW  0.72  0.63  0.03  0.08  Bottom round (flat) and eye of round, kg  10.85  12.23  0.37  0.06   % CSW  2.92  3.12  0.15  0.39  Top (inside) round, kg  12.89  14.58  0.26  0.01   % CSW  3.46  3.71  0.05  0.02  Knuckle (peeled), kg  11.51  12.87  0.34  0.04   % CSW  3.09  3.28  0.09  0.24  Hind shank meat, kg  3.31  3.40  0.08  0.45   % CSW  0.89  0.87  0.01  0.37  Bone-in hind shank, kg  8.03  8.02  0.25  0.97   % CSW  2.15  2.04  0.04  0.14  Femurs, kg  2.94  2.86  0.06  0.43   % CSW  7.89  7.29  0.02  0.09  Inside skirt, kg  3.17  3.48  0.21  0.40   % CSW  0.85  0.89  0.04  0.55  Outside skirt, kg  1.81  1.89  0.05  0.35   % CSW  0.49  0.48  0.004  0.28  Flank steak, kg  1.72  1.87  0.06  0.17   % CSW  0.46  0.48  0.02  0.70  Ligamentum nuchae, kg  0.79  0.78  0.13  0.97   % CSW  0.21  0.20  0.03  0.76  Bones, kg  52.59  54.74  2.08  0.51   % CSW  14.09  13.92  0.03  0.71  Inedible yield, kg  2.45  2.32  0.17  0.65   % CSW  6.58  5.91  0.05  0.44  Salable yield, kg  318.0  336.0  7.98  0.19   % CSW  85.25  85.49  2.43  0.53  Item  Days fed zilpaterol  SEM  P-value  0  20  Cold carcass side weight (CSW), kg  373.0  393.0  9.6  0.22  Lean trimmings, kg  195.5  204.4  5.9  0.35   % CSW  52.39  51.99  0.44  0.55  Mechanical knife trimmings, kg  5.02  4.54  0.17  0.12   % CSW  1.35  1.15  0.03  <0.01  SPB,2 kg  5.81  6.56  0.39  0.25   % CSW  1.56  1.67  0.06  0.28  Chuck (mock) tender, kg  2.28  2.63  0.06  0.02   % CSW  0.61  0.67  0.02  0.14  Chuck short rib, kg  4.44  4.47  0.08  0.78   % CSW  1.19  1.14  0.02  0.08  Rib eye roll, lip on (2 × 2), kg  12.56  13.54  0.08  <0.01   % CSW  3.37  3.45  0.07  0.49  Peeled tender, side muscle on, kg  5.70  6.17  0.21  0.20   % CSW  1.53  1.57  0.08  0.73  Strip loin (0 × 1), kg  12.81  14.06  0.40  0.10   % CSW  3.44  3.58  0.05  0.11  Top sirloin butt, kg  11.82  12.74  0.16  0.03   % CSW  3.17  3.24  0.05  0.31  Bottom sirloin tri-tip, kg  2.33  2.47  0.22  0.68   % CSW  0.62  0.63  0.05  0.92  Bottom sirloin flap, kg  2.70  2.47  0.17  0.39   % CSW  0.72  0.63  0.03  0.08  Bottom round (flat) and eye of round, kg  10.85  12.23  0.37  0.06   % CSW  2.92  3.12  0.15  0.39  Top (inside) round, kg  12.89  14.58  0.26  0.01   % CSW  3.46  3.71  0.05  0.02  Knuckle (peeled), kg  11.51  12.87  0.34  0.04   % CSW  3.09  3.28  0.09  0.24  Hind shank meat, kg  3.31  3.40  0.08  0.45   % CSW  0.89  0.87  0.01  0.37  Bone-in hind shank, kg  8.03  8.02  0.25  0.97   % CSW  2.15  2.04  0.04  0.14  Femurs, kg  2.94  2.86  0.06  0.43   % CSW  7.89  7.29  0.02  0.09  Inside skirt, kg  3.17  3.48  0.21  0.40   % CSW  0.85  0.89  0.04  0.55  Outside skirt, kg  1.81  1.89  0.05  0.35   % CSW  0.49  0.48  0.004  0.28  Flank steak, kg  1.72  1.87  0.06  0.17   % CSW  0.46  0.48  0.02  0.70  Ligamentum nuchae, kg  0.79  0.78  0.13  0.97   % CSW  0.21  0.20  0.03  0.76  Bones, kg  52.59  54.74  2.08  0.51   % CSW  14.09  13.92  0.03  0.71  Inedible yield, kg  2.45  2.32  0.17  0.65   % CSW  6.58  5.91  0.05  0.44  Salable yield, kg  318.0  336.0  7.98  0.19   % CSW  85.25  85.49  2.43  0.53  1Intervet/Schering-Plough Animal Health, Millsboro, DE. 2Small pieces and bits (100% visual lean denuded product). View Large Table 4. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on fabrication yield of concentrate-finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  Cold carcass side weight (CSW), kg  373.0  393.0  9.6  0.22  Lean trimmings, kg  195.5  204.4  5.9  0.35   % CSW  52.39  51.99  0.44  0.55  Mechanical knife trimmings, kg  5.02  4.54  0.17  0.12   % CSW  1.35  1.15  0.03  <0.01  SPB,2 kg  5.81  6.56  0.39  0.25   % CSW  1.56  1.67  0.06  0.28  Chuck (mock) tender, kg  2.28  2.63  0.06  0.02   % CSW  0.61  0.67  0.02  0.14  Chuck short rib, kg  4.44  4.47  0.08  0.78   % CSW  1.19  1.14  0.02  0.08  Rib eye roll, lip on (2 × 2), kg  12.56  13.54  0.08  <0.01   % CSW  3.37  3.45  0.07  0.49  Peeled tender, side muscle on, kg  5.70  6.17  0.21  0.20   % CSW  1.53  1.57  0.08  0.73  Strip loin (0 × 1), kg  12.81  14.06  0.40  0.10   % CSW  3.44  3.58  0.05  0.11  Top sirloin butt, kg  11.82  12.74  0.16  0.03   % CSW  3.17  3.24  0.05  0.31  Bottom sirloin tri-tip, kg  2.33  2.47  0.22  0.68   % CSW  0.62  0.63  0.05  0.92  Bottom sirloin flap, kg  2.70  2.47  0.17  0.39   % CSW  0.72  0.63  0.03  0.08  Bottom round (flat) and eye of round, kg  10.85  12.23  0.37  0.06   % CSW  2.92  3.12  0.15  0.39  Top (inside) round, kg  12.89  14.58  0.26  0.01   % CSW  3.46  3.71  0.05  0.02  Knuckle (peeled), kg  11.51  12.87  0.34  0.04   % CSW  3.09  3.28  0.09  0.24  Hind shank meat, kg  3.31  3.40  0.08  0.45   % CSW  0.89  0.87  0.01  0.37  Bone-in hind shank, kg  8.03  8.02  0.25  0.97   % CSW  2.15  2.04  0.04  0.14  Femurs, kg  2.94  2.86  0.06  0.43   % CSW  7.89  7.29  0.02  0.09  Inside skirt, kg  3.17  3.48  0.21  0.40   % CSW  0.85  0.89  0.04  0.55  Outside skirt, kg  1.81  1.89  0.05  0.35   % CSW  0.49  0.48  0.004  0.28  Flank steak, kg  1.72  1.87  0.06  0.17   % CSW  0.46  0.48  0.02  0.70  Ligamentum nuchae, kg  0.79  0.78  0.13  0.97   % CSW  0.21  0.20  0.03  0.76  Bones, kg  52.59  54.74  2.08  0.51   % CSW  14.09  13.92  0.03  0.71  Inedible yield, kg  2.45  2.32  0.17  0.65   % CSW  6.58  5.91  0.05  0.44  Salable yield, kg  318.0  336.0  7.98  0.19   % CSW  85.25  85.49  2.43  0.53  Item  Days fed zilpaterol  SEM  P-value  0  20  Cold carcass side weight (CSW), kg  373.0  393.0  9.6  0.22  Lean trimmings, kg  195.5  204.4  5.9  0.35   % CSW  52.39  51.99  0.44  0.55  Mechanical knife trimmings, kg  5.02  4.54  0.17  0.12   % CSW  1.35  1.15  0.03  <0.01  SPB,2 kg  5.81  6.56  0.39  0.25   % CSW  1.56  1.67  0.06  0.28  Chuck (mock) tender, kg  2.28  2.63  0.06  0.02   % CSW  0.61  0.67  0.02  0.14  Chuck short rib, kg  4.44  4.47  0.08  0.78   % CSW  1.19  1.14  0.02  0.08  Rib eye roll, lip on (2 × 2), kg  12.56  13.54  0.08  <0.01   % CSW  3.37  3.45  0.07  0.49  Peeled tender, side muscle on, kg  5.70  6.17  0.21  0.20   % CSW  1.53  1.57  0.08  0.73  Strip loin (0 × 1), kg  12.81  14.06  0.40  0.10   % CSW  3.44  3.58  0.05  0.11  Top sirloin butt, kg  11.82  12.74  0.16  0.03   % CSW  3.17  3.24  0.05  0.31  Bottom sirloin tri-tip, kg  2.33  2.47  0.22  0.68   % CSW  0.62  0.63  0.05  0.92  Bottom sirloin flap, kg  2.70  2.47  0.17  0.39   % CSW  0.72  0.63  0.03  0.08  Bottom round (flat) and eye of round, kg  10.85  12.23  0.37  0.06   % CSW  2.92  3.12  0.15  0.39  Top (inside) round, kg  12.89  14.58  0.26  0.01   % CSW  3.46  3.71  0.05  0.02  Knuckle (peeled), kg  11.51  12.87  0.34  0.04   % CSW  3.09  3.28  0.09  0.24  Hind shank meat, kg  3.31  3.40  0.08  0.45   % CSW  0.89  0.87  0.01  0.37  Bone-in hind shank, kg  8.03  8.02  0.25  0.97   % CSW  2.15  2.04  0.04  0.14  Femurs, kg  2.94  2.86  0.06  0.43   % CSW  7.89  7.29  0.02  0.09  Inside skirt, kg  3.17  3.48  0.21  0.40   % CSW  0.85  0.89  0.04  0.55  Outside skirt, kg  1.81  1.89  0.05  0.35   % CSW  0.49  0.48  0.004  0.28  Flank steak, kg  1.72  1.87  0.06  0.17   % CSW  0.46  0.48  0.02  0.70  Ligamentum nuchae, kg  0.79  0.78  0.13  0.97   % CSW  0.21  0.20  0.03  0.76  Bones, kg  52.59  54.74  2.08  0.51   % CSW  14.09  13.92  0.03  0.71  Inedible yield, kg  2.45  2.32  0.17  0.65   % CSW  6.58  5.91  0.05  0.44  Salable yield, kg  318.0  336.0  7.98  0.19   % CSW  85.25  85.49  2.43  0.53  1Intervet/Schering-Plough Animal Health, Millsboro, DE. 2Small pieces and bits (100% visual lean denuded product). View Large Cows fed ZH for 20 d had a decreased (P < 0.01) percentage of mechanical knife trimmings (1.15 vs. 1.35%) and a greater (P = 0.02) percentage of top (inside) round (3.71 vs. 3.46%) compared with cows not fed ZH. The increase in top (inside) round mirrors the findings reported by Boler et al. (2009) and Hilton et al. (2010) where steers fed ZH for at least 20 d had 0.23 to 0.24% more top (inside) round compared with steers that were not fed ZH. When feeding ZH, a numerically smaller percentage of chuck short rib (1.14 vs. 1.19%; P = 0.08), percentage of bottom sirloin flap (0.63 vs. 0.72%; P = 0.08), and percentage of femurs (7.29 vs. 7.89%; P = 0.09) was found (Table 4). Additionally, trimmings from cows fed ZH were numerically leaner (27.56 vs. 30.01% fat; P = 0.23) than control cows. No differences were detected for the remaining fabrication attributes. Because of a small sample size of only 3 fabrication sessions per treatment while conducting a mass fabrication, it was difficult to find differences between the treatments. The power (1 − β) of detecting a difference in total red meat yield was calculated to determine the probability of detecting a false statistical null hypothesis. This calculation indicated a power of 0.231 to detect a 0.5% difference in fabrication yield. Having a greater number of fabrication sessions or collection of individual fabrication data would increase sample size per treatment, thereby decreasing error and improving the ability to find more significant differences in red meat yield between the 2 treatment groups. Fabrication Value Cows fed ZH for 20 d had a greater (P ≤ 0.04) dollar value for chuck (mock) tender ($8.82 vs. $7.66), rib eye roll, lip on ($64.20 vs. $59.56), top sirloin butt ($35.60 vs. $33.01), top (inside) round ($60.30 vs. $53.33), knuckle (peeled; $44.26 vs. $39.57), and salable yield ($879.50 vs. $803.70) compared with cows not fed ZH (Table 5). Cows fed ZH for 20 d had numerically greater dollar values for lean trimmings ($401.90 vs. $362.90; P = 0.07), strip loin ($49.13 vs. $44.75; P = 0.10), bottom round (flat), and eye of round ($44.23 vs. $39.23; P = 0.06) compared with cows not fed ZH. No value differences were found for the remaining fabrication attributes. Fabrication dollar value of cows fed ZH does not appear in previous literature and appears to be a novel addition. Feeding ZH to concentrate-finished cull cows 20 d before slaughter improves feeding performance, carcass yield characteristics, and boxed fabrication value. This technology can be used to add new value to cull cows. Table 5. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on fabrication value of concentrate-finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  Lean trimmings, $/carcass  362.90  401.90  11.23  0.07  Mechanical knife trimmings, $/carcass  10.35  9.36  0.36  0.12  SPB,2 $/carcass  20.98  23.67  1.42  0.25  Chuck (mock) tender, $/carcass  7.66  8.82  0.21  0.02  Chuck short rib, $/carcass  12.22  12.31  0.22  0.79  Rib eye roll, lip on (2 × 2), $/carcass  59.56  64.20  0.35  <0.01  Peeled tender, side muscle on, $/carcass  37.67  40.78  1.42  0.20  Strip loin (0 × 1), $/carcass  44.75  49.13  1.41  0.10  Top sirloin butt, $/carcass  33.01  35.60  0.45  0.03  Bottom sirloin tri-tip, $/carcass  8.35  8.87  0.79  0.67  Bottom sirloin flap, $/carcass  9.99  9.15  0.62  0.39  Bottom round (flat) and eye of round, $/carcass  39.23  44.23  1.37  0.06  Top (inside) round, $/carcass  53.33  60.30  1.07  0.01  Knuckle (peeled), $/carcass  39.57  44.26  1.15  0.04  Hind shank meat, $/carcass  10.59  10.88  0.24  0.44  Bone-in hind shank, $/carcass  13.99  13.97  0.44  0.97  Femurs, $/carcass  0.97  0.95  0.02  0.43  Inside skirt, $/carcass  11.97  13.12  0.80  0.40  Outside skirt, $/carcass  7.40  7.69  0.20  0.36  Flank steak, $/carcass  6.83  7.42  0.22  0.17  Ligamentum nuchae, $/carcass  0.87  0.86  0.14  0.95  Bones, $/carcass  11.02  11.47  0.44  0.51  Inedible yield, $/carcass  0.51  0.49  0.04  0.65  Salable yield, $/carcass  803.70  879.50  18.90  0.04  Item  Days fed zilpaterol  SEM  P-value  0  20  Lean trimmings, $/carcass  362.90  401.90  11.23  0.07  Mechanical knife trimmings, $/carcass  10.35  9.36  0.36  0.12  SPB,2 $/carcass  20.98  23.67  1.42  0.25  Chuck (mock) tender, $/carcass  7.66  8.82  0.21  0.02  Chuck short rib, $/carcass  12.22  12.31  0.22  0.79  Rib eye roll, lip on (2 × 2), $/carcass  59.56  64.20  0.35  <0.01  Peeled tender, side muscle on, $/carcass  37.67  40.78  1.42  0.20  Strip loin (0 × 1), $/carcass  44.75  49.13  1.41  0.10  Top sirloin butt, $/carcass  33.01  35.60  0.45  0.03  Bottom sirloin tri-tip, $/carcass  8.35  8.87  0.79  0.67  Bottom sirloin flap, $/carcass  9.99  9.15  0.62  0.39  Bottom round (flat) and eye of round, $/carcass  39.23  44.23  1.37  0.06  Top (inside) round, $/carcass  53.33  60.30  1.07  0.01  Knuckle (peeled), $/carcass  39.57  44.26  1.15  0.04  Hind shank meat, $/carcass  10.59  10.88  0.24  0.44  Bone-in hind shank, $/carcass  13.99  13.97  0.44  0.97  Femurs, $/carcass  0.97  0.95  0.02  0.43  Inside skirt, $/carcass  11.97  13.12  0.80  0.40  Outside skirt, $/carcass  7.40  7.69  0.20  0.36  Flank steak, $/carcass  6.83  7.42  0.22  0.17  Ligamentum nuchae, $/carcass  0.87  0.86  0.14  0.95  Bones, $/carcass  11.02  11.47  0.44  0.51  Inedible yield, $/carcass  0.51  0.49  0.04  0.65  Salable yield, $/carcass  803.70  879.50  18.90  0.04  1Intervet/Schering-Plough Animal Health, Millsboro, DE. 2Small pieces and bits (100% visual lean denuded product). View Large Table 5. Effects of feeding zilpaterol hydrochloride1 for 0 or 20 d on fabrication value of concentrate-finished cull cows Item  Days fed zilpaterol  SEM  P-value  0  20  Lean trimmings, $/carcass  362.90  401.90  11.23  0.07  Mechanical knife trimmings, $/carcass  10.35  9.36  0.36  0.12  SPB,2 $/carcass  20.98  23.67  1.42  0.25  Chuck (mock) tender, $/carcass  7.66  8.82  0.21  0.02  Chuck short rib, $/carcass  12.22  12.31  0.22  0.79  Rib eye roll, lip on (2 × 2), $/carcass  59.56  64.20  0.35  <0.01  Peeled tender, side muscle on, $/carcass  37.67  40.78  1.42  0.20  Strip loin (0 × 1), $/carcass  44.75  49.13  1.41  0.10  Top sirloin butt, $/carcass  33.01  35.60  0.45  0.03  Bottom sirloin tri-tip, $/carcass  8.35  8.87  0.79  0.67  Bottom sirloin flap, $/carcass  9.99  9.15  0.62  0.39  Bottom round (flat) and eye of round, $/carcass  39.23  44.23  1.37  0.06  Top (inside) round, $/carcass  53.33  60.30  1.07  0.01  Knuckle (peeled), $/carcass  39.57  44.26  1.15  0.04  Hind shank meat, $/carcass  10.59  10.88  0.24  0.44  Bone-in hind shank, $/carcass  13.99  13.97  0.44  0.97  Femurs, $/carcass  0.97  0.95  0.02  0.43  Inside skirt, $/carcass  11.97  13.12  0.80  0.40  Outside skirt, $/carcass  7.40  7.69  0.20  0.36  Flank steak, $/carcass  6.83  7.42  0.22  0.17  Ligamentum nuchae, $/carcass  0.87  0.86  0.14  0.95  Bones, $/carcass  11.02  11.47  0.44  0.51  Inedible yield, $/carcass  0.51  0.49  0.04  0.65  Salable yield, $/carcass  803.70  879.50  18.90  0.04  Item  Days fed zilpaterol  SEM  P-value  0  20  Lean trimmings, $/carcass  362.90  401.90  11.23  0.07  Mechanical knife trimmings, $/carcass  10.35  9.36  0.36  0.12  SPB,2 $/carcass  20.98  23.67  1.42  0.25  Chuck (mock) tender, $/carcass  7.66  8.82  0.21  0.02  Chuck short rib, $/carcass  12.22  12.31  0.22  0.79  Rib eye roll, lip on (2 × 2), $/carcass  59.56  64.20  0.35  <0.01  Peeled tender, side muscle on, $/carcass  37.67  40.78  1.42  0.20  Strip loin (0 × 1), $/carcass  44.75  49.13  1.41  0.10  Top sirloin butt, $/carcass  33.01  35.60  0.45  0.03  Bottom sirloin tri-tip, $/carcass  8.35  8.87  0.79  0.67  Bottom sirloin flap, $/carcass  9.99  9.15  0.62  0.39  Bottom round (flat) and eye of round, $/carcass  39.23  44.23  1.37  0.06  Top (inside) round, $/carcass  53.33  60.30  1.07  0.01  Knuckle (peeled), $/carcass  39.57  44.26  1.15  0.04  Hind shank meat, $/carcass  10.59  10.88  0.24  0.44  Bone-in hind shank, $/carcass  13.99  13.97  0.44  0.97  Femurs, $/carcass  0.97  0.95  0.02  0.43  Inside skirt, $/carcass  11.97  13.12  0.80  0.40  Outside skirt, $/carcass  7.40  7.69  0.20  0.36  Flank steak, $/carcass  6.83  7.42  0.22  0.17  Ligamentum nuchae, $/carcass  0.87  0.86  0.14  0.95  Bones, $/carcass  11.02  11.47  0.44  0.51  Inedible yield, $/carcass  0.51  0.49  0.04  0.65  Salable yield, $/carcass  803.70  879.50  18.90  0.04  1Intervet/Schering-Plough Animal Health, Millsboro, DE. 2Small pieces and bits (100% visual lean denuded product). 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TI - Zilpaterol improves feeding performance and fabrication yield of concentrate-finished cull cows
JO - Journal of Animal Science
DO - 10.2527/jas.2010-3422
DA - 2011-07-01
UR - https://www.deepdyve.com/lp/oxford-university-press/zilpaterol-improves-feeding-performance-and-fabrication-yield-of-2lsdeTX1Cs
SP - 2170
EP - 2175
VL - 89
IS - 7
DP - DeepDyve
ER -