Características de carcaças de bovinos Nelore inteiros vs castrados em duas idades, terminados em confinamento

Abstract

RESUMO -Objetivou-se avaliar os rendimentos em carcaça e cortes primários de bovinos da raça Nelore, submetidos aos tratamentos: C13 = castrados aos 13 meses de idade (n=26); C18 = novilhos castrados aos 18 meses de idade antes do confinamento (n=26) e INT = novilhos inteiros (n=25). Os animais foram confinados por 100 dias, recebendo dieta com 12% de proteína bruta, 2, Carcass characteristics of Nellore cattle kept intact or castrated at two ages, feedlot finishedABSTRACT -Carcass dressing and primary cuts of Nellore cattle, submitted to the treatments: C13 = steers castrated at 13 months of age (n=26); C18 = steers castrated at 18 months of age before feedlot (n=26) and INT = intact males (n=25) was evaluated in this researach. The animals were confined per 100 days, fed diet with 12,0 % crude protein, 2.9Mcal of DE/kg DM and forage to concentrate ratio of 60:40 (% DM), and slaughtered at 22 months of age. A completely randomized experimental design was used. The INT animals showed higher slaughter weight 395.0 kg, hot (214.89 kg) and cold -CCW (212.21 kg) carcass weights then castrated, without differences between castrated at different ages. The INT animals showed higher cold dressing percentage (53.71%) and Longissimus dorsi muscle area (LDA) (61.23 cm²) in relation to C13 (51.99% and 56.59 cm², respectively), without differences between C13 vs C18 and C18 vs INT. The sexual condition did not influence hot dressing percentage, chilling loss, LDA/100 kg CCW, carcass length, arm length and perimeter, and side cut. The INT animals showed lower values for fat thickness in relation to castrated, that did not differ between them. The INT animals showed higher percentage for forequarter (40.13) and lower for side cut (10.22) and saw cut (50.24) than C13 (38.33; 11.09 and 51.77, respectively) and C18 (38.82; 10.73 and 51.46, respectively), without difference between them. In absolute values, INT animals showed higher forequarter weight than castrated, which did not differ between them, and higher saw cut weight than C13.

Carcass characteristics and meat evaluation of Nelore cattle subjected to different antioxidant treatments

“…Therefore, carcass must provide maximum amount of muscle, minimum of bone, and an amount of fat that varies depending on consumer preference. The proximate composition of the beef was similar between treatments and with values similar to those obtained by Lawler et al (2004), Freitas et al (2008), Razook et al (2002), Rubiano et al (2009), Souza et al (2009), and Sestari et al (2012, when working with Nelore cattle. The exception is ether extract content, which was lower, possibly due to the lower energy density of the diets used in this study compared with the aforementioned authors, who aimed at higher weight gain.…”

“…These tissue proportions can be explained by the grazing system and were similar to those reported by several authors working with Nelore and their crossbreds fed Brachiaria sp., with or without supplementation of corn and wheat bran (Razook et al, 2002;Vaz et al, 2002;Ribeiro et al, 2004;Freitas et al, 2008;Souza et al, 2009). …”

Desempenho e exigências de energia e proteína de bovinos de corte em pasto suplementados

“…4). Freitas et al (2008), trabalhando com bovinos Nelore não castrados e castrados, em confinamento, recebendo dietas com 12% de PB e 2,9Mcal de ED/kg de MS, observaram pesos médios de carcaça quente de 214,89kg para os animais inteiros, com rendimentos de carcaça de 53,71%. O peso de carcaça quente observado pelos autores foi superior aos pesos encontrados neste estudo, uma vez que os animais foram terminados em confinamento.…”

Fontes de amido no concentrado de bovinos superprecoces de diferentes classes sexuais

“…Pádua et al (2004) observaram que machos não castrados apresentam taxa de crescimento em torno de 10 a 20% superior aos machos castrados, desde que mantidos em condições que lhes permitam expressar seu potencial de crescimento. Tal superioridade também foi citada por , Freitas et al (2008) 12,24a 11,09ab 0,44 0,01 0,20 18,83 CMS = consumo de matéria seca; CMO = consumo de matéria orgânica; CPB = consumo de proteína bruta; CEE = consumo de extrato etéreo; CFDN = consumo de fibra em detergente neutro; CFDA = consumo de fibra em detergente ácido; CCNF = consumo de carboidratos não fibrosos; CCa = consumo de cálcio; CP = consumo de fósforo; PCI= peso corporal inicial; PCF = peso corporal final (ao abate); GPT = ganho de peso total no período (17-32 semanas de confinamento); GMD = ganho médio diário; EA = (GMD/CMS*100) = eficiência alimentar.…”