Estimation of direct and maternal genetic parameters for preweaning traits in the Asturiana de los Valles beef cattle breed through animal and sire models

Abstract

‘Asturiana de los Valles’ is a local beef cattle breed mainly distributed in the central and western part of Asturias but it is also present in other parts of Spain (CANON et al. 1994). Asturias is a region located in the Cantabric branch in the north of Spain where animals are bred in very hard conditions on the steep slopes of the highlands. The importance of the breed has increased dramatically, mainly due to two reasons: the breed has one of the leanest carcasses in Europe (VALLEJO et al. 1993), and there is a growing demand for semen for crossbreeding with Holstein Friesian in Spain (about 300 000 per year). Most of the animals are kept on an extensive grazing pasture system for 200 days/year. There are even some farms close to the sea where the animals are managed under a regular confinement semi-intensive system to breed animals with the muscular hypertrophy syndrome. Performance recording is organized in 25 centres with an average of 22 herds in each, grouped by proximity and production system. The mean farm size is very small which makes the maintenance of sires difficult and consequently, leads to much artificial insemination (about 25 %, from 9 to 57 % depending on areas), generating close connections among animals. During the last three decades, the number of animals with muscular hypertrophy syndrome has increased, and almost all the sires for artificial insemination, and many of the dams, now have this trait. Records have been collected over the last eight years and there now is an acceptable data set which may provide the knowledge of the parameters required, for genetic evaluation of the animals.