Validation of the 9-11th rib cut to estimate the chemical composition of the dressed carcass and of the whole empty body of Zebu cattle

This study was conducted to validate the 9-11th rib cut to estimate the chemical composition of the carcass and of the empty body weight (EBW) of Zebu cattle. Nineteen Zebu steers with initial body weight of 266.5±32.2 kg were used. Four steers were slaughtered at the beginning to compose the reference group; three were fed at maintenance level, and the remaining were allotted to different planes of nutrition (5.0%, 35.0% and 65.0% concentrate levels in the diets, DM basis). The 9-11th rib cuts and half of the carcasses were dissected and the weights of fat, muscle and bone tissue were recorded. The components fat, muscle and bone tissue from the 9-11th rib cut and from the half carcass were sampled and chemical analysis of fat, protein, water, ash and minerals determined. The 9-11th rib cut satisfactorily estimated the physical composition of the carcass, but not the chemical composition. The 9-11th rib cut appropriately estimated the chemical composition of the carcass in terms of protein, water, ash and macro mineral content. For the percentage of fat and Ca, an over- and underestimation of 7.84% and 13.34%, respectively, were detected. Regression equations were fitted to estimate the percentage of fat and Ca in the carcass, and that of protein, water and ash in the whole empty body.