Environmental effects, population genetic parameters, breeding value, phenotypic and genetic trend for age at first calving of Limousin cows

Some environmental effects, population genetic parameters, breeding value of Limousin bulls, also phenotypic and trends in the age at first calving (AFC) cows between 1992 2013 were estimated. Data served by Blonde d’Aquitaine Breeders Association, Hungary. The study was extended to three herds 1157 cows. GLM method used for different BLUP animal model estimation parameters values (BV), one-way linear regression analysis trend calculations. overall mean AFC estimated be 34.7±0.4 months. contribution evaluated factors phenotype as follows: herd 73.51%, birth year cow 13.02%, sire 6.74%, season 1.62%. heritability proved low (h2 = 0.08±0.07 h2 0.01±0.04). There relatively small differences BV studied sires AFC. Based on calculation, decreased an average 0.33 months per year, however no significant change found during period.