Características da carcaça de novilhos 5/8 Nelore-3/8 Charolês abatidos em diferentes estádios de desenvolvimento

Abstract

RESUMO -Foram avaliadas as características quantitativas das carcaças de novilhos 5/8 Nelore-3/8 Charolês terminados em confinamento até estes atingirem o peso médio de abate (P) de 425, 467 e 510 kg. Os novilhos apresentaram ao início do confinamento idade média de 660 dias, peso de 361 kg e estado corporal de 2,9 pontos. A dieta oferecida, com relação volumoso:concentrado de 60:40 na base matéria seca (MS), continha 10,25% de proteína bruta e 72,18% de nutrientes digestíveis totais. O volumoso foi silagem de milho contendo 46,5% de grãos na MS. O rendimento de carcaça fria ( Ŷ = 37,618+0,011Pi+0,028P) aumentou linearmente com o P. No entanto, quando o rendimento de carcaça foi expresso em relação ao peso de corpo vazio (PCV) este não foi influenciado pelo P. A espessura de gordura subcutânea na carcaça fria ( Ŷ = -15,499-0,001Pi+0,047P), expressa por 100 kg de carcaça fria ( Ŷ = -1,724-0,006Pi+0,013P) e PCV ( Ŷ = -1,124-0,003Pi+0,008P) aumentou com o avanço do P. A área do músculo Longissimus dorsi aumentou linearmente com o P ( Ŷ = -33,471 + 0,120Pi + 0,121P), no entanto, quando expresso por 100 kg de carcaça fria decresceu ( Ŷ = 45,173-0,023Pi-0,028P) e quando expresso por 100 kg de corpo vazio não foi influenciada pelo peso de abate. A porcentagem do corte serrote decresceu ( Ŷ = 63,007-0,001Pi-0,026P), enquanto a do costilhar elevou-se ( Ŷ = -3,053+0,005Pi+0,030P) com o aumento do P. A espessura de coxão ( Ŷ = 6,223+0,014Pi+0,0310P), comprimento de carcaça ( Ŷ = 58,564+0,0916Pi+0,075P), perna (Y=28,326+0,061Pi+0,050P) e perímetro de braço ( Ŷ = 9,173+0,053Pi+0,017P) foram influenciados positivamente pelo aumento do peso de abate dos animais. A conformação da carcaça não foi alterada pelo peso de abate.Palavras-chave: cortes comerciais, gordura subcutânea, Longissimus dorsi, peso de corpo vazio Carcass Characteristics of 5/8 Nellore-3/8 Charolais Steers Slaughtered at Different Maturity StagesABSTRACT -The carcass quantitative characteristics of 5/8 Nellore-3/8 Charolais steers feedlot finished to reach slaughter weight (SW) of 425, 467 and 510 kg, were studied. At the beginning of the feedlot the average age, weight and body condition were, respectively, 660 days, 361 kg and 2.9 points. The diet offered, with 60:40 roughage:concentrate relation, dry matter basis (DM), contained 10.25% crude protein and 72.18% of total digestible nutrients. The roughage was corn silage with 46.5% of grain in the DM. Cold carcass dressing percentage showed linear relation with SW ( Ŷ = 37.618 + .011Pi (initial weight) + .028SW). However, when dressing percentage was expressed in relation to empty body weight (EB), it was not influenced by SW. Subcutaneous fat thickness expressed per cold carcass ( Ŷ = -15.499 -.001Pi + .047SW), per 100 kg of cold carcass weight ( Ŷ = -1.724 -.006Pi + .013SW) and per 100 kg of EB ( Ŷ = -1.124 -.003Pi + .008SW) increased as SW increased. Longissimus dorsi area increased linearly with SW ( Ŷ = -33.472 + .120Pi + .120SW), however, when expressed per 100 kg of cold carcass weight it declined ( Ŷ ...

Animal performance and carcass characteristics of Nellore young bulls fed coated or uncoated urea slaughtered at different weights

“…In general, carcasses with better fat cover degree present lower loss during cooling, resulting in negative correlation between the two variables, according to the results published by Restle et al (1997) and Arboitte et al (2004b) and the present study, presenting significant correlation (r= -0.45). According to Restle et al (1997), the variation in shrinkage loss is also associated with the oscillations that occur in the cold chamber (temperature, wind speed, number of carcasses).…”

“…Feed conversion (FC) worsened as the slaughter weight increased, corroborating the literature (Costa et al, 2002a;Arboitte et al, 2004a;Cruz et al, 2004a). Costa et al (2002a) reported that with increase in animal weight feed efficiency is lowered, and this is due to the differences in the composition of weight gain.…”

“…With this slaughter weight, the estimated FC was 6.5 kg DM ingested/kg of gain. Arboitte et al (2004a) verified that ADG decreased linearly as slaughter weight increased. This deceleration in weight gain in the final stage of confinement can be suggested mainly as being a result of the greater energy requirement for maintenance and composition of gain (NRC, 1996), wherein the proportion of fat tissue in gain increases along with the body weight and proportional reduction in DMI, and consequently, the higher the body weight, the lower the DMIBW.…”

“…The data found in the literature about DMI according to slaughter weight are contradictory. Bailey et al (1985), Galvão et al (1991), Jorge et al (1997) and Mello (2007) observed increases in DMI, expressed in kg/day, of diets as the slaughter weight increased, whereas Van Koevering et al (1995), Costa et al (2002a), Arboitte et al (2004a) and Cruz et al (2004a) did not observe any alteration. This demonstrates that there is variation in ingestion and that other factors, such as genetics, weight at maturity and type of diet, can interfere with this parameter.…”

“…According to Arboitte et al (2004b), this result reflects the intensification of the fat deposition process as the animals reach adult weight. However, Restle et al (1997) reported that in order to reach the desired fat cover degree, animals must be fed for a longer period, since fat cover is a tissue of late deposition and increases proportionally with the age and weight of cattle.…”