Effects of different five-day progesterone-based synchronization protocols on the estrous response and follicular/luteal dynamics in dairy cows

DOI Web Site Web Site PubMed 参考文献41件
  • LÓPEZ-GATIUS Fernando
    Agrotecnio Centre, University of Lleida, Lleida 25198, Spain Department of Animal Production, University of Lleida, Lleida 25198, Spain
  • LÓPEZ-HELGUERA Irene
    Agrotecnio Centre, University of Lleida, Lleida 25198, Spain
  • DE RENSIS Fabio
    Department of Food Science, University of Parma, Parma 43121, Italy
  • GARCIA-ISPIERTO Irina
    Agrotecnio Centre, University of Lleida, Lleida 25198, Spain Department of Animal Production, University of Lleida, Lleida 25198, Spain

この論文をさがす

抄録

This study compared the responses shown by lactating dairy cows to four different P4-based protocols for AI at estrus. Cows with no estrous signs 96 h after progesterone intravaginal device (PRID) removal were subjected to fixed-time AI (FTAI), and their data were also included in the study. In Experiment I, follicular/luteal and endometrial dynamics were assessed every 12 h from the beginning of treatment until AI. The estrous response was examined in Experiment II, and fertility was assessed in both experiments. The protocols consisted of a PRID fitted for five days, along with the administration of different combinations of gonadotropin releasing hormone (GnRH), equine chorionic gonadotropin and a single or double dose (24 h apart) of prostaglandin F2α. In Experiment I (40 cows), animals receiving GnRH at the start of treatment showed a significantly higher ovulation rate during the PRID insertion period while estrus was delayed. In Experiment II (351 cows), according to the odds ratios, cows showing luteal activity at the time of treatment were less likely to show estrus than cows with no signs of luteal activity. Treatment affected the estrous response and the interval from PRID removal to estrus but did not affect conception rates 28–34 days post AI. Primiparous cows displayed a better estrous response than multiparous cows. Our findings reveal acceptable results of 5-day P4-based protocols for AI at estrus in high-producing dairy cows. Time from treatment to estrus emerged as a good guide for FTAI after a 5-day P4-based synchronization protocol.

収録刊行物

参考文献 (41)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ