Divides 52 Holstein cattle of 13~15 months years old into group A and B stochastically, then carrying duplicative superovulation treatment with FSH + Estrumate and CIDR + FSH + PGF2a separately.

• 以荷斯坦奶牛及其胚胎为实验材料,采用FSH+Estrumate法和CIDR+FSH+PGF2a法进行重复超排处理;