USE OF SINGLE OR MULTIPLE INJECTIONS OF FSH IN EMBRYO COLLECTION PROGRAMS IN GOATS

The yield of embryos from goats treated with single injections of FSH combined with low doses of PMSG was compared with that from goats trea ted with conventional superovulatory regimens based on multiple doses of FSH. In one experiment, 101 female goats were assigned to 10 groups . One group received six injections of FSH-P (FSH-P control); a second group received eight injections of Ovagen (Ovagen control). The remai ning eight groups conformed to a 2 x 2 x 2 factorial design in which g oats received a single injection of a low or high dose of either FSH-P or Ovagen in combination with a low or high dose of PMSG. All goats w ere run with harnessed, entire bucks. Ovaries were examined by laparos copy and embryos were recovered from goats that had ovulated and been mated. The mean number of normal embryos collected per goat was signif icantly greater in the FSH-P control group in all except those groups treated with either low or high doses of PMSG combined with a low dose of Ovagen or a low dose of PMSG combined with a high dose of Ovagen. Most goats ovulated and ovulation rates were not significantly differe nt from the mean of the FSH-P control, except for those treated with a low dose of FSH-P combined with either low or high doses of PMSG. Emb ryo recovery rates were significantly lower in groups treated with a h igh dose of PMSG combined with a high dose of either Ovagen or FSH-P, or with low doses of PMSG and FSH-P, than in the FSH-P control. Fertil ization rates and the proportion of normal embryos did not differ sign ificantly among groups. In a second experiment, in which 10 goats were given the FSH-P control treatment, or an injection of low or high dos e Ovagen combined with low dose PMSG, the mean number of normal embryo s per goat was not significant. It is concluded that superovulatory pr otocols based on single injections of FSH combined with PMSG may give similar results in conventional regimens based on multiple doses of FS H.