Portal de Periódicos da CAPES

Diferenças observadas em progênies de touros nelore, testados em prova de ganho de peso e com diferenciais de seleção nulo ou positivo para peso pós-desmama, em um rebanho P.O.

1994; INSTITUTO DE ZOOTECNIA IZ/APTA-SAA/SP; Volume: 51; Issue: 1 Linguagem: Inglês

1981-4100

Alexander George Razook, Leopoldo Andrade de Figueiredo, Luiz Martins Bonilha Neto,

Genetic and phenotypic traits in livestock

In the 1988/89 breeding season at the Estacao Experimental de Zootecnia de Sertaozinho, State of Sao Paulo, Brazil, 5 nelore purebred bulls with known selection differentials (SD) for 378 day post-weaning weight (P378), selected in a performance test (PGP) were utilized in a different nelore purebred herd. Two of these bulls (LC) were selected in a nelore control herd where they had an average of -2.6 kg of SE) for P378. The three other bulls (LS) were selected in a selection line where they presented an average SD of +45.8 kg Each bull was mated to 28 cows during 90 days of breeding season (lst December 88/27 February 89). The observed differences in the LS bull’s progeny compared to those of LC were +3.2, +9.1 and +12.0kg respectively for weights at birth (PN), four months (P120) and weaning (P210), for both males and females. The LS bulis also produced heavier progenies (+ 14.2 kg) for P378 in PGP. Observed differences in favor of LS bulls were +20.0 kg for heifer’s yearling weight (P550). The LS bulls also produced progenies with higher feedlot daily gain (G1l2) and also higher external measures like hip height (ALT) and chest girth (TORAX). These results showed that Nelore performance tested bulls, having high selection differeials for P378 (within herds), as an indication of good breeding value for that character, produced progenies with higher performance in a herd different from those where they were originally selected.