Evaluation of the response to buserelin administered 24 hours prior to artificial insemination in Sarda ewe: follicular dynamics after ovulation

Failure of fertilization and embryo loss during early gestation are major determinants of reproductive efficiency in Sarda ewe. A number of studies have demonstrated that treatment with the GnRH analogue buserelin on day 12 post insemination reduces embryo mortality in cattle and sheep. In response to this treatment, large ovarian follicles (LF) and circulating oestrogens are supposed to decrease; the resulting elevation in progesterone secretion, due to the increased number of active corpora lutea (CL), should facilitate embryo implantation. The aim of this research was to investigate the ovarian effect of buserelin adminstered 24 h prior to A.I. in Sarda ewe.