Abstract

The myostatin mutation in Limousin cattle affects both dressing percent and meat yield, without a negative impact on calving difficulty. A trial was designed to introgress this mutation into Angus cattle, using double-copy Limousin bulls to produce F1 Limousin x Angus. Crossing the F1 individuals would produce F2 individuals with a quarter carrying two copies of the mutation. A pure-bred Angus herd was maintained as a Control, for breed and genotype comparisons. A total of 269 F1, 34 F2 and 129 Angus calves were born in the first four years of this trial, before a lack of funding led to early closure. A total of 112 surplus bulls were slaughtered, and measurements taken over three years, including a “butchers’ dissection” into saleable meat, fat and bone of one hind-quarter per animal. Limousin crosses were 9% heavier as yearlings, 7% heavier at slaughter and had 2.3% higher dressing percent (55.3% vs. 53.0%) than Angus. Hindquarters from Limousin crosses were 14% heavier than from Angus, and their meat yields were greater by 1.8% (77.0% vs.75.2%), due mainly to breed differences in bone weight. Overall, the Limousin-cross advantage was 6.5 kg (17%) of saleable meat per hind-quarter, with most of the extra meat in high-value cuts.

NG, Cullen, CA Morris, KR Taukiri, and SW Hill

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 189-193, 2010