ABSTRACT
Superovulation protocols using single injection of pregnant mare serum gonadotropin [PMSG] or minipumps with follicle - stimulating hormone [FSH] were compared in cattle for determine the ovarian responsibility and producing a large number of good quality embryos suitable for transfer. Superovulation protocols were done using a single injection 3500 IU of PMSG or 36 mg of FSH with a decreasing doses for 4 consecutive days commencing on day 10 of normal estrus cycle, cows [n=20], ovarian responsibility was followed by ultrasonography per rectum starting 2 days before superovulation treatments and continuing until flushing. All follicles >/= 4mm were measured and recorded, considered largest follicles >/= 10mm and ovarian structures were mapped each day. The obtained results showed that, cows treated with FSH produced a greater number of CLs [8.20 vs 6.20 / cow] and a lower number of unovulated follicles [1.4 vs 1.5/cow] than the cows treated with PMSG. Recovery rate total embryos was insignificantly higher in the cows treated with FSH [81.7 vs 70.9] than the cows treated with PMSG, the transferable embryos recorded highly significant difference for the cows treated with FSH [77.6 vs 52.3] than the cows treated with PMSG [P,0.01]. On the other hand, number of follicles, average different follicles diameter and average diameter of largest follicles were significantly higher [P<0.01] in the cows treated with FSH than the cows treated with PMSG either the right or left ovary at the day of artificial insemination [AI]. While, at the day of flushing, the average diameter of largest unovulated follicles were insignificantly higher in the cows treated with FSH than the cows treated with PMSG. In conclusion, the present study suggest that the cows treated with FSH for superovulation results in an increase in the number of large follicles and reduce the number of unovulated follicles than that the cows treated PMSG. The best good quality embryos was recorded with the cows treated with FSH for superovulation in embryo transfer programes