Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 1998
Publication Date: N/A
Technical Abstract: Double-muscled Piedmontese animals have a mutation in the myostatin gene (MSTN), that appears to be responsible for muscle hypertrophy. The objective of this study was to establish the effect of the mutation in the myostatin gene on early life weights and calving ease in a population segregating the Piedmontese allele. Calves of Piedmontese inheritance, born in 1995 (n=66 surviving to weaning; no DNA was obtained on calves tha died before weaning) and 1996 (n=72; 13 not surviving to weaning), were evaluated for birth weight (BWT; kg), adjusted weaning (W200; kg), and yearling (W365; kg) weight, calving ease (CE), and survival (SUR). The number of copies of the Piedmontese allele was assessed by sequencing MSTN from each calf. Data were analyzed with a model that included the effects of year, sex, interaction between line of dam and sire, number of Piedmontese allele copies at MSTN nested within the interaction, and age of fdam as covariate. The number of copies of the Piedmontese allele was a significant source of variation for BWT. The means for individuals with zero, one, and two copies of the Piedmontese allele were 37.5 +/- .7 kg, 41.1 +/- .6 kg, and 42.8 +/- 1.3 kg, respectively. A significant difference (P=.005) was observed between individuals inheriting zero and one copies of the Piedmontese allele (3.13 +/- 1.1 kg), while the difference between one and two copies approached significance (P=.1). From 1996 calves not surviving to weaning, nine were homozygous for double muscling, three were heterozygous, and one had zero Piedmontese allele copies. There was no evidence of an effect of MSTN on CE. Mating schemes that maximize production of animals with one copy of the Piedmontese MSTN allele would be expected to increase BWT without effecting CE.