Heritability of reproductive traits in Asturiana de los Valles beef cattlebreed

Heritability was estimated for four reproductive traits in the Asturiana de los Valles breed in order to evaluate the possibility of include this info rmation in the breed's current improvement program. The estimations were do ne using an animal model except for calving ease score. For this last trait , a threshold model under a sire model-was fitted, with the sire effect as the only random effect in the model besides the residual. Estimated heritab ilities for calving interval age at first calving, gestation length, as dam traits, and calving ease were 0.12, 0.27, 0.15 and 0.42, respectively. The estimated heritability for calving interval and age at first calving could justify a sire selection program in the Asturiana de los Valles breed taki ng account their female offsprings' reproductive characteristics. Heritabil ity estimates for gestation length and calving ease suggested a close genet ic relationship of these two traits and birth weight. Further research is n eeded to estimate the genetic (co)variances between these three traits to a llow the use of this information in a breed improvement program to reduce d ystocia without affecting preweaning growth traits.