title: Active immunization with a synthetic fragment of pig inhibin alpha-subunit increases ovulation rate and embryo production in superovulated ewes but season affects its efficiency.
abstract: Two experiments were designed to determine the effects of active immunization against one of two synthetic peptides from humans (inhibin-like peptide) or pigs (inhibin alpha-subunit) on antibody titres, ovulation rate and embryo production in ewes superovulated with 16 U ovine FSH. In Expt 1, during the breeding season, 30 ewes were subdivided into three groups: group I served as the non-immunized control; group II was immunized against inhibin-like peptide (100 micrograms inhibin-like peptide equivalent, followed by three booster injections); group III was immunized against pig inhibin alpha-subunit conjugated to human serum albumin (96 micrograms for the primary administration and 46 micrograms for the booster). In Expt 2, the efficiency of immunization against pig inhibin alpha-subunit on ovarian response and embryo production was evaluated during the non-breeding season in two groups of ewes (n = 12): group IV was a non-immunized control; Group V was immunized against pig inhibin alpha-subunit. During the breeding season, the ewes immunized against pig inhibin alpha-subunit showed higher antibody titres compared with the group immunized against inhibin-like peptide (P < 0.01) and a significant increase in ovulation rate (12.1) compared with both the control (5.0; P < 0.05) and the inhibin-like peptide-immunized group (3.1; P < 0.01). Immunization against pig inhibin alpha-subunit increased transferable embryo yield 4.5-fold (6.7 versus 1.5; P < 0.01) and improved embryo quality (94.6 versus 40.6%; P < 0.01). During the non-breeding season, immunization against pig inhibin alpha-subunit enhanced ovulation rate from 2.6 in the controls to 9.4 (P < 0.01) but did not affect transferable embryo production (3.9 versus 2.1; P > 0.05) and significantly lowered their quality (54.1 versus 100%; P < 0.01). In conclusion, active immunization against pig inhibin alpha-subunit can improve superovulatory response during the breeding season, while it appears to be unable to increase embryo yield during the seasonal anoestrus.
authors.affiliation: Department of Animal Production, University of Bari, Italy.
authors.forename: A
authors.initials: A
authors.lastname: D'Alessandro
authors.forename: G
authors.initials: G
authors.lastname: Martemucci
authors.forename: N
authors.initials: N
authors.lastname: Iaffaldano
mesh_terms: D000780:Anestrus; D000818:Animals; D001947:Breeding; D004624:Embryo Transfer; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006728:Hormones / Q000008:administration & dosage; D006801:Humans; D007265:Inhibins / Q000502:physiology*; D008098:Litter Size; D016015:Logistic Models; D010060:Ovulation / Q000276:immunology*; D010455:Peptides / Q000008:administration & dosage*; D012621:Seasons; D012756:Sheep / Q000502:physiology*; D013480:Superovulation; D013552:Swine; D014611:Vaccination
chemical_list: D006728:Hormones; D010455:Peptides; C094377:inhibin-alpha subunit; D007265:Inhibins; D005640:Follicle Stimulating Hormone