ptimization of Estrus Synchronization Protocol for Target Breeding to Decrease Voluntary Waiting Period in Lactating Cows
2017
Md. Parvez Kabir, Bangladesh Agricultural University, Mymensingh, Bangladesh | Md. Rashedul Islam, Bangladesh Agricultural University, Mymensingh, Bangladesh | Abdulla Al Maruf, Bangladesh Agricultural University, Mymensingh, Bangladesh | Mohammed Shamsuddin, Bangladesh Agricultural University, Mymensingh, Bangladesh | Farida Yeasmin Bari, Bangladesh Agricultural University, Mymensingh, Bangladesh | Nasrin Sultana Juyena, Bangladesh Agricultural University, Mymensingh, Bangladesh | Md Saidur Rahman, Bangladesh Agricultural University, Mymensingh, Bangladesh
Effective estrus detection and artificial insemination (AI) are necessary for profitable management of dairy herd. In current study, 45 crossbred lactating cows have been selected with the complaint of unobserved oestrus for more than sixty days postpartum. All cows had functional corpus luteum as examined by transrectal ultrasonography. Cows were treated with PGF2α analogue and AI was performed with observed oestrus and then single dose of GnRH was administered. Similar synchronization protocol has been repeated after 14 days in cows that did not repose to first treatment. Remaining cows received additional PGF2α after 14 days of second treatment and timed AI was performed following GnRH administration. Among 45 cows, 28.89% showed estrus after first treatment and 78.79% responded to second hormonal intervention. A higher conception rate (88.89% vs 26.66 and 72.72%) was observed in cows after triple administration of PGF2α and timed AI. We noticed a significant differences in body condition score (BCS, 1~5 scale), postpartum period, and daily milk production between cows that either responded of non-responded following first and second hormonal treatment. In addition, there was a significant positive correlation between daily milk production and BCS, age and postpartum days, milk production and estrus/BCS, and milk production/BCS/estrus and conception rate. Depending upon the findings we conclude that hormonal intervention with PGF2α and GnRH enhances postpartum ovarian cyclicity and help decreasing the days open of dairy herd. Therefore, this finding might provide an excellent guideline for target breeding system for profitable dairy herd management.
显示更多 [+] 显示较少 [-]