Estimation of genetic parameters for stillbirth of Japanese Black cattle in Kagoshima

Reproductive ability is receiving increased attention from beef cattle producers in Japan due to the high production cost and insufficient supply of feeder calves in Japanese Black. In this study, we estimated genetic parameters of stillbirth in Japanese Black cattle in Kagoshima, and defined stillbirth as calf mortality between 244 days after successful insemination and a day after parturition. We used 213,261 calving records excluding multiple births from Japanese Black cattle in Kagoshima during three Japanese fiscal years (2010 to 2012). The single-trait threshold sire maternal grandsire model was used for parameter estimation. The single-trait threshold sire-MGS model was used for parameter estimation. The annual incidence of stillbirth ranged from 1.8% to 2.2%. The estimated heritability both direct and maternal for stillbirth was 3.2% and 3.5%, respectively. This estimate was lower than that previously reported in Japanese Black cattle.