Exogenous Hormonal Manipulation of Ovarian Activity in Dairy Cattle: Impact on reproduction and fertility.

Abstract

Event Abstract Back to Event Exogenous Hormonal Manipulation of Ovarian Activity in Dairy Cattle: Impact on reproduction and fertility. Mokhtar E. Benhanifia1* 1 Ibn-Khaldoun University, Institute of Veterinary Sciences, Algeria Introduction. Integrated reproductive management in cattle is considered essential to optimise reproductive performance. Oestrus synchronization can facilitate artificial insemination (AI) in cattle by reducing the time and cost of detection but in some AI programs, only 50% of cows are correctly identified when in oestrus. Although estrogens are important veterinary medicinal products used for therapeutic and zootechnical purposes, the use of oestradiol-17β and its related ester derivatives in food-producing cattle for the purposes of oestrous synchronisation is prohibited in the European Union, New Zealand and Australia. So, the aim of the study was to compare the efficiency of new hormonal treatments; Ovsynch (GnRH-PGF2α) with PRID (Progesterone Releasing Intravaginal Device) in lactating dairy cows (n= 154) in central and western Algeria. Methods. Cows were randomly assigned to two experimental groups. Cows in Group 1 (n = 65) were treated with progesterone releasing intravaginal device (PRID) and received AI 56 hours after withdrawal of the device. Cows in Group 2 (n = 89) were treated with GnRH i.m. (Gonadorelin 0.1 mg/ ml Fertagyl-Intervet) without regard to the stage of the estrous cycle (day of treatment, day 0), followed by 25 mg of PGF2α i.m. (Luprostiol–7mg Prosolvin-Intervet) 7 days later. A second-treatment of the same GnRH analogue (Gonadorelin 0.1 mg/ ml i.m.) was given 48 h after PGF2α and the cows received TAI 16-24 h after the second injection of GnRH. The efficacy of treatments was evalued at Day 25 (NRR: non return rate) and Day 90 (PR: Pregnancy rates) after TAI. Results. NRR ranged between 45.7 to 65.5% (mean 57.4%) in central Algeria, while in Western Algeria NRR ranged between 52.3 to 60% (55.7%). No significant difference was observed (P>0.05). Pregnancy rates (PR) were similar in the two groups treatments: PRID, Ovsynch (33.8% versus 33.7%, P>0, 05) Conclusion. As a conclusion, the use of Ovsynch for synchronization in lactating dairy cattle resulted in similar pregnancy rates following synchronized AI compared to a typical PRID device treatment. Further research is necessary to determine the costs and benefits associated with regimens utilising GnRH (reduce treatment length, dose of GnRH), and other alternative treatments protocols should be further investigated in our conditions (Prostaglandin-based regimens, gonadotropins; FSH, LH, PMSG, Gonadotrophin-releasing hormone and prostaglandin combinations). Finally, coordination of management strategies to maximize production and reproductive performance will optimize early return to cyclicity in post-partum cows, and oestrous response and pregnancy rates in heifers and cows, taking into consideration the suitable alternatives to the use of oestradiol 17ß in synchronisation regimens. Keywords: Reproduction, artificial insemination, Estrogens, progestagens, GnRH, PGF2α Conference: 8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010, Thessaloniki, Greece, 1 Oct - 5 Oct, 2010. Presentation Type: Oral Topic: Xenobiotics and reproduction Citation: Benhanifia ME (2010). Exogenous Hormonal Manipulation of Ovarian Activity in Dairy Cattle: Impact on reproduction and fertility.. Front. Pharmacol. Conference Abstract: 8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010. doi: 10.3389/conf.fphar.2010.60.00104 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 Mar 2011; Published Online: 04 Nov 2010. * Correspondence: Dr. Mokhtar E Benhanifia, Ibn-Khaldoun University, Institute of Veterinary Sciences, Tiaret, 14000, Algeria, mbenhanifia@yahoo.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Mokhtar E Benhanifia Google Mokhtar E Benhanifia Google Scholar Mokhtar E Benhanifia PubMed Mokhtar E Benhanifia Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.