Reliability of U.S.D.A. beef carcass yield grades in reflecting differences in retail yields

Retail cut-out and U.S.D.A. yield grade data were obtained on 1,121 carcasses of steers from Hereford and Angus dams mated artificially to Hereford, Angus, Jersey, Limousin, South Devon, Simmental and Charolais bulls. Calves were weaned when approximately 215 days old, conditioned 28 days, fed an average of 218 days after weaning before being slaughtered in a commercial slaughter plant. Carcass cooler data were obtained and the right side of each carcass was cut into closely trimmed, essentially boneless retail cuts at the KSU food service building. Beef yield grades do reflect definite differences in retail yields. Statistical tests indicated less than one chance in 1,000 that such differences occurred by chance and that the yield grade differences were real. The average difference in retail product percentage between yield grades was 4.6 percent. The average difference in fat trim percentage was 5.6 percent. For 700-pound carcasses, that\u27s a difference of 39.2 pounds of waste fat, or 32.2 pounds of retail product. The difference in bone percentage would account for the other 7 pounds

White sorghum grain (Funk\u27s G766W) and elevator-run red sorghum grain compared for fattening cattle

An new white variety of sorghum grain (Funk\u27s G766W) has been reported to be higher in digestible dry matter and protein than elevator-run, rod sorghum grain. A 120-day field trial was conducted on the George and Vernon Miller farm near Great Bend to compare the two sorghum grain types under feed-lot conditions

Effect of adding fat to feedlot rations

Fat is added to commercial feedlot rations as a concentrated energy source and to reduce dustiness and wear of feed processing machinery. We added fat at varying levels ( 0 to 6% of the ration) to study effects from fat and the influence of a surface-active additive. Two hundred 700-pound steers were allotted to 40 pens of 5 each all fed 135 days on the rations show in Table 12, according to the schedule shown in Table 13

Equações para previsão aproximada de rendimento de carcaça em gado Nelore e Nelore mestiço

Carcass data were used to develop equations for predicting weights of several cut-out yields for bulls from two experiments conducted at the Instituto de Zootecnia in São Paulo, Brazil. These data of 72 young bulls were obtained from 32 Nellore, 18 1/2 blood Marchigiana-Nellore, 12 1/2 blood Chianina-Nellore and 10 1/4 blood Marchigiana-Nellore. Equation 1, used to predict weight of trimmed total carcass cuts (Y = -6.8074 + 0.8021 (chilled carcass weight in kilograms - 3.1021 (kidney and pelvic fat percentage)+ 0.2743 (fat thickness in millimiters)), would seem to be the most useful, since it utilizes three easily obtainable variables and is highly accurate (R2 = 0.96). Chilled carcass weight was the independent variable with the greatest contribution in all prediction equations. All the models included chilled carcass weight and kidney and pelvic fat percentage as independent variables.Foram utilizados os resultados obtidos com dois trabalhos experimentais conduzidos no Instituto de Zootecnia, em São Paulo, no desenvolvimento de equações para estimar várias características de carcaça. Dados de carcaça de 72 tourinhos jovens, sendo 32 Nelore, 18 1/2 sangue Marchigiana-Nelore, 12 1/2 sangue Chianina-Nelore e 10 1/4 Marchigiana-Nelore foram usados no desenvolvimento das equações. A equação 1, usada para estimar o peso da porção comestível da carcaça (Y = -6,8974 + 0,8021 (peso da carcaça resfriada em quilogramas) -3,1021 (percentagem de gordura renal e pélvica + 0,2743 (espessura de gordura em milímetros), parece ser a mais útil, pois utiliza somente três variáveis, que são facilmente obtidas, além de ser de grande precisão (R2 = 0,96). O peso de carcaça resfriada foi a variável que apresentou a maior contribuição no desenvolvimento das equações. Todos os modelos estudados incluíam o peso de carcaça resfriada e a percentagem de gordura renal e pélvica como variáveis independentes

Carcass characteristics and yields of Nellore bulls compared with 1/2 and 1/4 blood Marchigiana-Nellore bulls

Trinta e seis tourinhos Jovens terminados em confinamento, dez nelore (grupo I), com média de idade de 689 dias e dez nelore, dez 1/4 marchigiana-nelore e seis 1/2 marchigiana-nelore (nelore II, cruzado I e cruzado II, respectivamente), com média de 613 dias de idade ao início do confinamento, foram divididos em três grupos e alimentados por 119,152 ou 175 dias antes do abate. O grupo de cruzados II apresentou maior (P< .05) peso vivo (513.5 kg) ao abate do que o nelore I, nobre II e cruzado I (476.0, 464.5 e 479.0 kg, respectivamente). Como consequência, o grupo de cruzados II apresentou maiores pesos de carcaça quente e resfriada do que os outros grupos. Também o grupo de cruzados II apresentou a mais fina (P< .05) espessura de gordura (3.5 mm), enquanto o grupo nelore II apresentou a camada mais espessa de gordura (6.1 mm), ficando intermediários o nelore I e cruzado I (4.7 e 4.6 mm respectivamente). A área do olho-de-lombo foi significativamente maior para o grupo cruzado II (79.65 cm2) do que para nelore I. nelore II e cruzado I (7039,68.57 e 65.93 cm2, respectivamente). O grupo de cruzado II também apresentou vantagem do ponto de vista de produção de maiores quantidades de carne magra, sem a produção excessiva e desnecessária de gordura, além de maior percentagem da porção comestível do traseiro especial (33.65%), maior porcentagem da porção comestível total (76.30%) e menor quantidade de gordura aparada (6.96%).Four groups totaling 36 young bulls were placed in a dry lot and individually fed a ration of 66% TDN. There were two groups of ten Nellore bulls (Nellore I and Nellore II) and two groups, one of ten one-quarter Marchigiana-Nellore and one of six one-half Marchigiana-Nellore bulls (crossbred I and crossbred II, respectively). Nellore I bulls averaged 689 days of age and the other three groups averaged 613 days of age at the start of the trial. All animals were randomly assigned to three slaughter time groups (1, 2 and 3) and were fed for 119, 152 or 175 days. The crossbred II bulls had heavier (P< .05) live weights (513.5 kg) at slaughter than the Nellore I, Nellore II and crossbred I groups (476.0, 464.5 and 479.0 kg respectively). Consequently, crossbred II bulls showed heavier (P< .05) hot and chilled carcass weights than the other groups. Also the crossbred II bulls had less (P< .05) 12th rib fat cover (3.5 mm) with Nellore II bulls having lhe thicker 12th rib fat cover (6.1 mm) and Nellore I and crossbred I groups being intermediate (4.7 and 4.6 mm respectively). Loin eye area was larger (P < .05) for crossbred II (79.65 cm2) than for Nellore I, Nellore II and crossbred I groups (70.39, 68.57 and 65.93 cm2respectively). A marked advantage was shown for the crossbred II group from the standpoint of producing greater quantities of lean meat without excess waste fat. This group had higher (P< .05) proportion of edible portion from the special hindquarter (33.65%), higher (P< .05) proportion of total edible portion (76.30%) and lesser amounts of trimmable fat (6.96%)

Nutritional effects of beef connective tissue characteristics and eating qualities

We compared taste panel and connective tissue characteristics of beef fed a high energy diet with beef fed grass. The high energy diet produced higher USDA quality and yield grades, more rapid weight gain, and increased connective tissue collagen synthesis arid breakdown. But, it did not consistently improve taste panel and shear characteristics over grass-feeding

Supplementing feedlot steers and heifers with Zilmax increases proportions of strip loin, chuck clod, and top sirloin steaks exceeding Warner-Bratzler shear force thresholds, whereas aging moderates this effect

Ractopamine hydrochloride (Elanco, Greenfield, IN) and Zilmax (zilpaterol hydrochloride; Intervet/Schering-Plough, Millsboro, DE) are β-adrenergic agonists approved in the United States and several other countries to increase growth rate, improve efficiency of feed utilization, and increase carcass meat yield. Zilmax has been shown to improve feed efficiency by 26% and increase hot carcass weight, longissimus muscle area, and meat yield. However, a few studies have shown that Zilmax significantly increased Warner-Bratzler shear force values (decreased tenderness). The objectives of our research were to determine the effects of supplementing feedlot diets of steers and heifers with Zilmax for 0, 20, 30, or 40 days before harvest and the subsequent effects of 7, 14, and 21 days of aging on tenderness of steer and heifer Longissimus lumborum (from strip loins) and heifer Triceps brachii (from chuck clods) and Gluteus medius (from top sirloin butts) muscles