Genetic evaluation for growth traits, reproductive performance, and meat tenderness in beef cattle

A genetic evaluation of Bali cattle (Bos javanicus) using data from the Bali Cattle Improvement Project on the island of Bali was conducted. Results showed that contemporary group, sex of calf, age of calf and dam affected growth traits. Genetic improvement through selection for W-350d (h2d = 0.5) might be achieved more quickly than selection for W-190d (h2d = 0.4) and their positive direct genetic correlation (rd = 0.74). The estimates of maternal effects in Bali cattle were not different from 0; however, the genetic correlation between direct and maternal was moderately negative. The decline in W-350d might be caused by factors other than genetic due to the observed genetic values of W-190d and W-350d .; A second study of the response to divergent selection for meat tenderness using Warner-Bratzler Shear Force (WBSF) values of Angus bulls was conducted at the Santa Fe Beef Research Unit of the University of Florida. Results have shown that selection for meat tenderness decreased WBSF (0.32 kg/year) and its associated genetic values (0.03 kg per year) and the heritability of WBSF was found to be high (h2d = 0.40 +/- 0.18), indicating that WBSF can be effective as a selection tool to genetically improve beef tenderness.; A third study that evaluated the responses to estrous synchronization following timed-artificial insemination in heifers and cows of differing proportions of Angus and Brahman breeding was conducted at Beef Research Unit of the University of Florida. Results have shown that year of breeding, body condition, age and breed types of cows affected estrous, pregnancy and calving rate, and gestation length. The reproductive performance of cows subjected to estrous synchronization and timed-AI was not affected by the percentage of Brahman breeding. However, the tendency for high levels of Brahman breeding in cows to result in longer gestation lengths is of concern.