Effect of exogenous FSH on ovulation rate in homozygous carriers or noncarriers of the booroola FECB gene after hypothalamic-pituitary disconnection or after treatment with a GNRH agonist

Abstract

We have tested the hypothesis 'that the ovulation rate in homozygous carriers (BB) and noncarriers (++) of the Booroola FecB gene would not be different if the plasma concentrations of follicle-stimulating hormone (FSH) in the two genotypes were similar'. For this purpose we used two experimental animal models: 1) the hypothalamic-pituitary disconnected (HPD) ovary-intact ewe; and 2) the GnRH agonist (i.e., Deslorelin)-treated ewe. Following HPD or Deslorelin treatment, the animals had low plasma concentrations of gonadotropins and were anovulatory. In both animals models, BB and ++ ewes were treated with exogenous pregnant mares serum gonadotropin (PMSG) and varying doses of FSH to induce p..