Use of single or multiple injections of FSH in embryo collection programmes 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 treated 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 remaining eight groups conformed to a 2x2x2 factorial design in which goats 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 were run with harnessed, entire bucks. Ovaries were examined by laparoscopy and embryos were recovered from goats that had ovulated and been mated. The mean number of normal embryos collected per goat was significantly 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 different 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. Embryo recovery rates were significantly lower in groups treated with a high 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.(ABSTRACT TRUNCATED AT 250 WORDS)