Trends and Genetic Parameters of Growth Trait of Charolais Herd Raised in the Rio Grande do Sul State

The objective of this work was to determine, through the genetic trend, the genetic progress of Charolais herds raised in the Rio Grande do Sul State, and the results utilized in programs of genetic improvement for this breed. The data were collected by PROMEBO (Beef Breeding Program) and the analyses were performed at the Animal Breeding Laboratory of the Animal Science Department of the Universidade Federal de Santa Maria. It was estimated the heritabilities (h²) and the breeding values (BV) by means of the DFREML program (Boldman et al., 1995) to determine the annual direct and maternal genetic tendency for birth weight (BW) and weight gain from birth to weaning (WGBW) with the PROC REG (Sas, 1996). The results showed direct and maternal heritabilities of .54 and .12 for BW and .12 and .05 for WGBW, respectively. There were no significant direct trend of -10.46 and 40.85 g/year and a maternal genetic trend of 2.38 and -10.34 g/year, for BW and WGBW, respectively. These results indicate that there was no genetic progress in this population, although significant phenotypic progresses for both characteristics were verified. This results leads to conclusion that there is a necessity of adoption of a genetic improvement program in this breed, considering that the population is improving phenotipically and the results would show in a short period of time.

birth weight; genetic progress; weight gain from birth to weaning