Culling of ejaculates from crossbred bulls during deep freezing

摘要

The fertility of bovine semen can be enhanced by the culling of sub-standard ejaculates. Bratton et al., (1956) reported that as the per cent of culled ejaculates increased form 10 to 40 per cent, fertility enhanced from +1.4 to +4.6 per cent. The present study was aimed to investigate the various reasons for the culling of ejaculates of crossbred bulls at different stages of deep freezing during different seasons of the year and to explore the possibility of managing the semen freezing activity during the best favourable season.