Parámetros genéticos del crecimiento y la reproducción en ganado cebú

Abstract

In order to know the genetic correlations between the growth characteristics in bulls and the reproductive characteristics in Zebu cows of Cuba, 9.490 registries of bulls were used. They finished the test of behavior in pasturing, and to which the final weight (PF ) at 18 months of age, and 13.575 registries of their half-sisters was registered with the age to the first insemination (EPI), the age to the first childbirth (EPP) and the services by gestation (SXG). The data were collected in five Genetic Centers between 1988 and 2001. All the animals were children of 267 bulls. The values found averages were of 343,3 kg, 26,5 months, 37,7 months and 1,76 for PF, EPI, EPP and SXG, respectively. The indices of inheritance (h2) were of 245, 054, 091 and 021 for PF, EPI, EPP and SXG, respectively. The genetic correlations between the reproductive PF and characteristics oscillated between -216 and -0.340. Between the reproductive characters, the genetic correlations went from 544 to 0.982. One concluded that the values of h2 considered for Zebú cattle in Cuba are within the rank published in the international literature and that the selection continued for the increase of the corporal weight to the 18 months of age in the bulls would not negatively affect the reproductive efficiency in cows.