Chemical composition of whole body and carcass of Bos indicus and tropically-adapted Bos taurus breeds

• Grant number: 11/06799-5
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: May 01, 2011
• End date: October 31, 2011
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Sarah Figueiredo Martins Bonilha
• Grantee: Sarah Figueiredo Martins Bonilha
• Host Institution: Instituto de Zootecnia. Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Nova Odessa , SP, Brazil

Abstract

Relationships between the chemical composition of the 9-11th rib section and the chemical composition of the carcass and empty body were evaluated for Bos indicus (108 Nellore and 36 Guzerah, GuS) and tropically-adapted Bos taurus (56 Caracu, CaS) bulls, averaging 20 to 24 mo of age at slaughter. Nellore cattle were represented by 56 animals from the selected herd (NeS) and 52 animals from the control herd (NeC). The CaS and GuS bulls were from selected herds. Selected herds were based on 20 years of selection for post-weaning BW. Carcass composition was obtained after grinding, homogenizing, sampling, and analyzing soft tissue and bones. Similarly, empty body composition was obtained after grinding, homogenizing, sampling, analyzing, and combining blood, hide, head + feet, viscera, and carcass. Bulls were separated into two groups. Group 1 was comprised of 36 NeS; 36 NeC; 36 CaS; and 36 GuS bulls and had water, ether extract (EE), protein, and ash chemically determined in the 9-11th rib section and in the carcass. Group 2 was comprised of 20 NeS; 16 NeC; and 20 CaS bulls and water, EE, protein, and ash were determined in the 9-11th rib section, carcass, and empty body. Linear regressions were developed between the carcass and the 9-11th rib section compositions for group 1 and between carcass and empty body compositions for group 2. The 9-11th rib section percentages of water (RWt) and EE (RF) predicted the percentages of carcass water (CWt) and carcass fat (CF) with high precision: CWt, % = 29.0806 + 0.4873 × RWt, % (r2 = 0.813, SE = 1.06) and CF, % = 10.4037 + 0.5179 × RF, % (r2 = 0.863, SE = 1.26), respectively. Linear regressions between % of CWt and CF and empty body water (EBWt) and empty body fat (EBF) were also predicted with high precision: EBWt, % = -9.6821 + 1.1626 × CWt, % (r2 = 0.878, SE = 1.43) and EBF, % = 0.3739 + 1.0386 × CF, % (r2 = 0.982, SE = 0.65), respectively. Chemical composition of the 9-11th rib section precisely estimated carcass percentages of water and EE. These regressions can accurately predict carcass and empty body compositions for Nellore, Guzerah, and Caracu breeds. (AU)