Effects of passive immunization using antibody against an α-inhibin peptide on follicle-stimulating hormone concentrations and litter size in sows

Abstract The objective of the experiment was to determine whether passive immunization against inhibin at weaning would increase FSH secretion and thereby influence postweaning reproductive performance in sows. Commercial Yorkshire sows (n = 173) were assigned within parity to 5 α-inhibin fragment antibody (α-IF-Ab) dosage groups: 0 (control), 3.25, 6.5, 13 and 26 RP-2 kU/kg α-IF-Ab. Antibody had been semipurified from ovine antisera raised against α-IF, a peptide that mimicked the N-terminal region of inhibin's α-subunit. A RP-2 U refers to a laboratory reference preparation. Sows were administered a single intramuscular injection of control solution or α-IF-Ab just before 21-d-old piglets were weaned. Blood samples were taken immediately before immunization and 24 h later. Sows were bred upon expression of estrus. Serum α-IF-Ab titers in sows 24 h following passive immunization increased (P