5Bari F,Khalid M,Wolf B,etal. The repeatability of su- perovu-larory response and embryo recovery in sheep [J]. Theriogenology,2001,56(1) :147-55.
6Hunter R H F. Physiology and technology of repro- duction in female domestic animals[M].London:Aca- demic Press, 1980.
7Remy B,Baril G,Vallet J C,et al. Are antibodies re- sponsible for a decreased superovulatory responsein- goats which have been treated repeatedly with porcine follicle-stimulating hormone [ J ]. Theriogenology, 1991,36(3) :389-399.
8A1-Kamali A A,Boland M P,Crosby T F,et al. Re- duced superovulatory response in the ewe lolling re- peated gonadotrophin treatment [J]. Vet Rec, 1985, 116(7) : 180-181.