Genetic trend of stillbirths in Japanese Black cattle

Abstract Text: The objective of our study was to investigate the genetic trend for stillbirths in Japanese Black cattle. Calving records of Japanese Black cattle were collected from breeding stations of the National Livestock Breeding Center between January 2005 and November 2012 (n = 3255). To investigate the genetic trend of stillbirth, the average estimated breeding value (EBV) for each birth year for sire-maternal grand sire (MGS) were used. For the prediction of EBV, threshold sire-MGS model was assumed. The model included herd-year, sex, the inbreeding coefficient of calves, gestation length, twin birth, month, and parity as fixed effects. The average phenotypic stillbirth ratio was 2.64%. Average EBVs were relatively constant from 1988 to 2010. However, there were high EBV sire relative groups. This suggests that stillbirths may be decreased by the selection of sires that have a low genetic risk.

Keywords:

Beef cattle
Stillbirth
Genetic trend