Factores ambientales y parámetros genéticos para algunas características reproductivas en bovinos Chacuba.

The aim of the study was to analyze the impact of environmental factors as well as to estimate components of (co) variance of reproductive traits in Chacuba cattle. For that, 4,957 records of cows, daughters of 893 dams and 110 sires were used. Models that considered number of parity, calf sex, and contemporary group (herd-year-season of calving) as fixed effects were tested. The season of calving was included as every two, three, four and six months. The interval from calving to conception (ICC), calving interval (CI), and services per conception (SC) were the traits analyzed with uni and multitrait models using the software ASReml. The parity (P<0.01) and the contemporary groups (P<0.01) significantly affected the reproductive traits; however, the calf sex (P>0.05) was not. The heritability for the traits analyzed were low with values of 0.14±0.02, 0.15±0.02 and 0.04±0.01 for ICC, CI and SC, respectively. Genetic correlations were high between ICC and CI (0.99±0.43) but low between ICC and SC (0.10±0.14) and between CI and SC (0.09±0.11). Genetics parameters estimation models for the traits ICC, CI, and SC for Chacuba cows should consider parity and herd-year-quarter contemporary groups. Indirect selection for the calving interval using the interval calving-conception, can be implemented given the genetic correlation between these traits. [ABSTRACT FROM AUTHOR]