Estimation the genetic parameters for age at first calving in Charolais and Limousine breeds

The objective of this study was to estimate the genetic parameters for age at first calving in Charolais and Limousine cattle breeds using animal model. The reproduction traits are influenced by genetic factors and environmental factors. The genetic factors are breed, individual and environmental factors are: climate condition and nutrition. The data consisted on 239 records for Charolais breed and 309 records for age at the first calving for Limousine breed. The data were from Romanian Breeding Association for Beef cattle. The age at the first calving was 792.92±6.77 days for Charolais breed and 813.83±6.09 days for Limousine breed. The heritability value for age at the first calving was 0.273 for Charolais and for Limousine breed was 0.275. The breeding values of cows with records for age at first calving were between −30.697 and 40.929 for Limousine breed were between −46.64 and 42.65. For improvement the reproduction traits it is necessary to improve the environmental conditions and supervision of reproduction activity in the farms and the selection of the best cows. The selection based on the breeding values of the cows determined the improvement of age at first calving. Improvement the reproduction traits increase the profitability of farms.