SUPEROVULATORY RESPONSE AND EMBRYO PRODUCTION IN NON-PROLIFIC MALPURA SHEEP ACTIVELY IMMUNIZED AGAINST SYNTHETIC INHIBIN PEPTIDES

摘要

The aim of this study was to determine the superovulatory response and embryo production of a non-prolific tropical breed of sheep by active immunization against inhibin-based peptide immunogens. A total of 9 Malpura ewes were randomly selected from three groups (n=3 from each group) of animals that were immunized one and half years ago against the synthetic peptides fromithe alpha_C [bIalpha(1-29)-Tyr ] 30-mer peptide (Group I) or alpha_N [bI- -Tyr (153-167)Cys ] 17-mer peptide (Group II) area of the bovine inhibin a-subunit conjugated to ovalbumin or against ovalbumin as control (Group III). Estrus was synchronized using indigenous progesterone sponges and PMSG (200 IU) during spring (minor breeding season) and the ewes exhibiting estrus were hand-mated. Ovaries were examined with the aid of laparoscope followed by midventral laparotomy for collection of embryos. The ewes belonging to Group I exhibited estrus early lasting for a longer duration and had higher ovulation rate, compared to ewes belonging to Group II and Group III. A total of 14 good quality embryos from 4 ewes, representing 3 from Group I and 1 from Group II, were collected after flushing. The results showed that active immunization against synthetic a-subunit bovine inhibin peptides could be used as an alternate technique to the use of exogenous gonadotrophins for superovulation in sheep and the immunized ewes can also be used as donor for production of quality embryos.