title: Efficacy of Ovsynch protocol in cyclic and acyclic Egyptian buffaloes in summer.
abstract: The aim of the present study was to evaluate the efficacy of an Ovsynch protocol in the cyclic and non-cyclic Egyptian buffaloes in the summer. The present study was carried out on 21 Egyptian pluriparous buffalo cows (11 cyclic and 10 acyclic) and 8 heifers (5 cyclic and 3 acyclic). All animals were administered 100 microg GnRH i.m. at Day 0, 500 microg of PGF2 proportional, variant i.m. at Day 7 and a second dose (100 microg) of GnRH i.m. at Day 9. Ovarian structures of the animals were recorded by means of transrectal ultrasonography (6-8 MHz linear-array transducer) daily from Day 0 (before treatment) to Day 9 (the second GnRH administration) and thereafter, at 12-h interval till ovulation or for a maximum of 48 h. After ultrasound examination, a blood sample was taken daily from each animal for progesterone analysis. The buffalo cows were inseminated at 16-20 h after 2nd GnRH administration. After the first administration of GnRH, 46% (5 of 11) of cyclic and 50% (5 of 10) of acyclic cows and 40% (2 of 5) of cyclic and 33% (1 of 3) of acyclic heifers responded by ovulation or luteinization of the follicles. The mean diameters (+/-S.E.M.) of the follicles in the responding cows and heifers were significantly higher than those in non-responding animals (9.7 +/- 0.4 mm vs. 6.7 +/- 0.6 mm, P < 0.0001; 11.1 +/- 1.5 mm vs. 7.3 +/- 0.7 mm, P < 0.05, respectively). After the second administration of GnRH, 81% (9 of 11) of cyclic and 60% (6 of 10) of acyclic cows and 80% (4 of 5) of cyclic and 33% (1 of 3) of acyclic heifers ovulated, respectively. Ovulations occurred earlier (P = 0.059) and over a wider range of time in the non-cyclic cows (26 +/- 4.8 h; range: 12-36 h) and in a heifer (12 h,) than in the cyclic cows (34.7 +/- 1.3 h; range 24-36 h) and heifers (33 +/- 3 h; range: 24-36 h). The conception rate was 18% (2 of 11) and 0% (0 of 10) in cyclic and non-cyclic cows, respectively. In conclusion, the Ovsynch protocol could be used effectively for synchronization of ovulation in cyclic cows and heifers in summer.
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Kafr El-Sheikh University, 13561 Kafr El-Sheikh, Egypt. alykaren@hotmail.com
authors.forename: Aly M
authors.initials: AM
authors.lastname: Karen
authors.forename: Samy A
authors.initials: SA
authors.lastname: Darwish
mesh_terms: D000780:Anestrus / Q000097:blood / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002020:Buffaloes / Q000097:blood / Q000502:physiology*; D002417:Cattle; D002985:Clinical Protocols; D003008:Cloprostenol / Q000008:administration & dosage; D004334:Drug Administration Schedule; D004534:Egypt; D030762:Estrous Cycle / Q000097:blood / Q000187:drug effects / Q000502:physiology*; D004973:Estrus Synchronization / Q000379:methods*; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage; D007315:Insemination, Artificial / Q000662:veterinary; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000097:blood; D012621:Seasons; D016896:Treatment Outcome
chemical_list: D005300:Fertility Agents, Female; D007987:Gonadotropin-Releasing Hormone; D003008:Cloprostenol; D011374:Progesterone