Angus beef cattles and Hereford beef cattles imported from Canada were superovulated by using CIDR and injecting FSH-PG in May to June and Augest to September 2004, which were grouped in random.

• 采用放置CIDR和FSH-PG注射法,于2004年5至6月和8至9月间对进口的安格斯和海福特肉牛进行超数排卵研究,并对安格斯和海福特肉牛随机分组。