Performance, carcass, and palatability traits for cull cows fed high-energy concentrate diets for 0, 14, 28, 42, or 56 days.

Abstract

Cull cows, thin to moderate in initial condition scores, were randomly assigned within breed to slaughter groups and fed a high-concentrate diet for 0, 14, 28, 42 or 56 d (n = 40). Carcass data were collected, and one side of each carcass was fabricated into boneless subprimals, lean trimmings, fat, and bone. Live and carcass weights, ADG, and dressing percentage increased through 28 d of feeding (P < .05), and lean firmness increased (P < .05) through 42 d of feeding. Adjusted preliminary yield grades and final yield grades increased (P < .05) with feeding, but not to levels requiring knife trimming of fat. Fat color became whiter (P < .05) but marbling was not affected (P > .05) by feeding. Weights of fat-free lean, fat, and bone and percentages of fat in soft tissues of cow carcasses increased (P < .05) by 28 d on feed. Overall steak tenderness was higher (P < .05) for cows fed 56 d than for cows fed 0 or 14 d. Warner-Bratzler shear force was not affected by feeding. Amounts of soluble collagen increased (P < .05) in the longissimus muscle between 0 and 28 d on feed, and total collagen decreased (P < .05) in the biceps femoris muscle between 0 and 42 d on feed. Continental European cow carcasses yielded more fat-free lean and less fat (P < .05) and dairy cows generally provided the most tender product across all slaughter periods. In general, sensory tenderness and yields of cow carcass components increased without requiring excessive trimming of fat by feeding cull beef and dairy cows for periods up to 56 d.

Características da carcaça de vacas de descarte de diferentes grupos genéticos terminadas em confinamento com distintos pesos

“…Estes resultados refletem a intensificação da deposição do tecido adiposo quando os animais atingem peso elevado. Aumentos na deposição de gordura subcutânea frente ao aumento do peso de abate de vacas de descarte são relatados na literatura, variando em intensidade, principalmente em função do nível energético da dieta e do grupo genético (Wooten et al, 1979;Matullis et al, 1987;Cranwell et al, 1996;Schnell et al, 1997).…”

“…Além disso, esta prática de terminação não proporciona o adequado grau de acabamento na carcaça (3 a 6 mm de gordura de cobertura) exigido pelos frigoríficos (Grassi, 1980;Perobelli et al, 1995), principalmente em raças mais tardias. Trabalhos conduzidos no exterior indicam maior deposição de gordura subcutânea frente ao aumento do peso de abate de vacas de descarte, variando em intensidade, sobretudo em função do nível energético da dieta e do grupo genético (Wooten et al, 1979;Matullis et al, 1987;Cranwell et al, 1996;Schnell et al, 1997).…”

Composição física da carcaça, qualidade da carne e conteúdo de colesterol no músculo Longissimus dorsi de novilhos 5/8 Nelore - 3/8 Charolês terminados em confinamento e abatidos em diferentes estádios de maturidade

“…3 Marbling: 1 to 3 -traces; 4 -light; 7 -small; 10 -mean; 13 -moderate; 16 to 18 -abundant. Tabela 3 -Médias para cor, textura, marmoreio e marmoreio por 100 kg de carcaça fria (Marm CF) da carne, de acordo com o peso de abate Schnell et al (1997) não verificaram (P>0,05) influência no tempo de alimentação na deposição de marmoreio nas carcaças, sendo estas classificadas como "traços" para as vacas alimentadas por 0 e 14 dias e "leve" nos animais alimentados por 28, 42 e 56 dias, provavelmente, em razão do pequeno número de dias entre os períodos. May et al (1992) constataram em animais Hereford x Angus que a deposição de marmoreio apresentou comportamento quadrático, à medida que aumentou o tempo de alimentação, sendo o maior índice observado aos 112 dias de alimentação.…”

Quality Traits of Longissimus thoracis and lumborum and Gluteus medium Muscles from Cull Dairy Holstein-Friesian Cows

“…Within the dried-off population, cows finished fed produced meat with higher mean tenderness than counterparts not finished .61 N) but differences were not significant. This last effect has not always been reported in other studies, with the results of Schnell, Belk, Tatum, Miller and Smith (1997) and Franco et al (2009) showing shear force mean values in meat from finished fed animals for about 1 month to not being significantly different from controls or even showing greater shear force values. Besides any possible difference existing in protein turnover capacity between finished and not finished dried-off groups used in our study, the increase of subcutaneous fat deposition in carcasses and the higher mean IMF content in Gm muscle within the finishing fed animals may also be the source of its lower shear force mean value, by protecting against cold-shortening and increasing muscle tissue softness, respectively.…”