Immunization of goats against recombinant human inhibin α-subunit: Effects on inhibin binding, mating behaviour, ovarian activity and embryo yield

Boer goats were superovulated by immunization against the recombinant human inhibin α-subunit. The immune response to the antigen during the oestrous season varied greatly between animals, as judged by serum inhibin binding determined by enzyme-linked immunosorbent assay (ELISA). A booster injection administered during the anoestrous season elicited a prompt and rather uniform response and serum inhibin binding activity remained elevated in all goats throughout the remainder of the experiment. Both during the oestrous and anoestrous season, immunization increased the number of corpora lutea and unovulated follicles. Immunization shortened cycle length in some animals. The embryo yield from immunized goats during the oestrous and anoestrous season was over three times the number of embryos recovered from control animals. The recovery rates were 61% and 50%, respectively. Plotting the number of follicles and corpora lutea observed during the oestrous season against inhibin binding activity gave a positive correlation. Transfer of embryos recovered from the immunized animals resulted in 41% live births. These results indicate that immunization against the recombinant human inhibin α-subunit may be a useful alternative to the conventional approach of superovulation.