Evaluation of carcass characteristics of Bos indicus and tropically adapted Bos taurus breeds selected for post-weaning weight

¹ Department of Animal Science, Texas A&M University, College Station, TX 77843; Instituto de Zootecnia, Agência Paulista de Tecnologia dos Agronegócios, Sertãozinho, SP 14.160-900, Brazil; Departamento de Zootecnia, Universidade de São Paulo/ESALQ, Piracicaba, SP 13.418-900, Brazil. Bolsista CNPq
² Department of Animal Science, Texas A&M University, College Station, TX 77843
³ Departamento de Zootecnia, Universidade de São Paulo/ESALQ, Piracicaba, SP 13.418-900, Brazil. Bolsista CNPq
⁴ Instituto de Zootecnia, Agência Paulista de Tecnologia dos Agronegócios, Sertãozinho, SP 14.160-900, Brazil. Bolsista CNPql
⁵ Instituto de Zootecnia, Agência Paulista de Tecnologia dos Agronegócios, Nova Odessa, SP 13.460-000, Brazil
⁶ PRDTA Alta Mogiana, Agência Paulista de Tecnologia dos Agronegócios, Colina, SP 14.770-000, Brazil

^* To whom correspondence should be addressed. E-mail: luis.tedeschi{at}tamu.edu.

	Abstract

Data from 9 studies were compiled to evaluate the effects of 20 yr of selection for post-weaning weight (PWW) on carcass characteristics and meat quality in experimental herds of control Nellore (NeC) and selected Nellore (NeS), Caracu (CaS), Guzerah (GuS), and Gir (GiS) breeds. These studies were conducted with animals from a genetic selection program at the Experimental Station of Sertãozinho, São Paulo State, Brazil. After the performance test (168 d postweaning), bulls (n = 490) from the calf crops born between 1992 and 2000 were finished and slaughtered to evaluate carcass traits and meat quality. Treatments were different across studies. A meta-analysis was conducted with a random coefficients model in which herd was considered a fixed effect and treatments within year and year as random effects. Either calculated maturity degree or initial body weight were interchangeably used as covariates and least-squares means were used in the multiple comparison analysis. The CaS and NeS had heavier (P = 0.002) carcasses than NeC and GiS; GuS were intermediate. The CaS had the longest carcass (P < 0.001) and heaviest spare ribs (P < 0.001), striploin (P < 0.001), and beef plate (P = 0.013). Although the body, carcass, and quarter weights of NeS were similar to CaS, NeS had more edible meat in the leg region than CaS bulls. Selection for PWW increased rib-eye area in Nellore bulls. CaS had the lowest (most favorable) shear force values compared to NeS (P = 0.003), NeC (P = 0.005), GuS (P = 0.003), and GiS (P = 0.008). Selection for PWW increased body, carcass, and meat retail weights in Nellore without altering dressing percentage and body fat percentage.

Key Words: Caracu, Gir, growth, Guzerah, Nellore, selection