Longitudinal effects of muscular hypertrophy allele on milk production traits during the lactation using a novel equivalent model when molecular information is limited

Given that the mh allele causes the double muscling phenotype, this allele could also influence milk production traits of the dual purpose Belgian Blue cattle. However, all dual purpose Belgian Blue animals could not be genotyped. So, a new alternative strategy for the prediction of gene effects and especially their smooth integration into genetic evaluations based on an equivalent method was developed from existing theory. Developed equations were modified to allow that not all animals were genotyped. As expected, the mh allele had negative effects on milk production traits. For the first three lactations, the average estimated allelic substitution effects were -0.074 % fat content and -158.7 kg milk per lactation (305 days). Moreover, effects of mh allele were not constant during the lactation