Evaluation of different protocols for synchronization of estrus and ovulation in postpartum subestrus lactating dairy cows
Abstract: Thirty three Friesian cows in postpartum subestrus were used in this study to compare two protocols for synchronization of estrus and ovulation with that of standard. 1 or 2 injections of PGF2aa . Cows were divided randomly into three treatment groups as follows: Group 1 (OvSynch): GnRH (Day 0. 50 μμg im). PGF2aa (Day 7. 500 μμg im). G n RH (Day 9, 50μμg im). TAl 8 - 20 h later: Group 2 (GnRH – PGF2aa): Cows were synchronized using the same manner however. the second injection of GnRH was eliminated, AI 12 h after exhibiting estrus or at 80 - 96 h for cows which not displayed estrus; Group 3 (PGF 2aa): (Day 0. 500 μμg im). AI 12 h after detection of estrus or. if estrus not observed, cows received a second PGF2aa injection on Day 14, and AI 12 h after observed estrus or. at 80 - 96 h when estrus was absent. The results showed that conception rates at d 35 post AI was significantly (P<0.05) higher for cows in Group 2 (77.8%) than in Group 1 (63.6%) and Group 3 (50%). Similarly. Group 2 had a higher pregnancy rate (66.7; P<0.05) at d 65 post AI THAN Group 1(54.6%) and Group 3 (40%). Howeverوpregnancy losses did not differ among treated groups. Estimated saving in hormone costs required for synchronizing estrus and ovulation was LE 4.17 and LE 15.75 per pregnancy for Group 1 and 2, respectively. It could be concluded that GnRH-PGF2aa or GnRHPGF2aa-GnRH treatment was effective method for synchronizing a fertile estrus in postpartum subestrus lactating dairy cows. But, the better reproductive performance was observed in cows treated with GnRH-PGF2aa protocol.
Publication year 2004
Pages 797-811
Availability location معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى - الجيزة
Availability number
Organization Name
City طنطا
serial title Journal Agricultural Research Tanta University
Author(s) from ARC
External authors (outside ARC)
    ابراهيم محمود عبد الرازق جامعة طنطا
    ابراهيم سعد الشماع جامعة طنطا
Agris Categories Animal physiology - Reproduction
AGROVOC
TERMS		 Dairy cows. Gnrh. Ovulation. Perinatal period. Synchronization.
Proposed Agrovoc estrus;
Publication Type Journal
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