GENETIC ANALYSIS OF REPRODUCTIVE TRAITS IN BALI CATTLE MAINTAINED ON RANGE UNDER ARTIFICIALLY AND NATURALLY BRED

The aim of this study was to evaluate genetic analysis including heritability and further phenotypic and genetic trends of reproductive traits in Bali cattle. Reproductive traits studied were age at first calving (AFC), calving interval (CI) and pregnancy rate (PR). Data of reproductive traits were collected from Breeding Centre of Bali Cattle, Denpasar-Bali at the year period of 2000-2007. To evaluate the genetic analysis, heritability were estimated using the Mixed Model Least Squares and Maximum Likelihood procedure. The phenotypic and genetic trends were calculated using regression equation. Estimation of heritability for AFC, CI and PR were 0.22, 0.41 and 0.40, respectively. The phenotypic trend of AFC, CI and PR decreased at an average rate of 1.70 month, 10.4 days and 0.75% per year, respectively. The same pattern was showed for genetic trends for AFC, CI and PR decreased at 0.38 month, 4.25 days and 0.30% per year respectively in the same period. The heritability of reproduction traits in Bali cattle were considered as moderate to high (0.22-0.41) which means that the selection program will be more effective and efficient in improving the genetic merits in Bali cattle.