Estrous synchronization efficiency of Buserelin of different doses in combination with mifepristone and timed artificial insemination in holstein cattle

Abstract

The reproductive performance of lactating dairy cattle remains a major factor affecting herd's profitability; estrous synchronization and timed artificial insemination (TAI) enable producers to maximize the reproductive efficiency of their herd. A total of 88 cows were used to measure the effect of mifepristone 0.4 mg/kg with different doses of Buserelin (10 μg, 20 μg and 40 μg/head) on estrous synchronization efficiency for the same period in cattle. Buserelin was injected at day 0-followed by PG (day=7)-Buserelin + mifepristone (0.4 mg/kg) (day=9) (BPBMH synchronization protocol), results revealed that Buserelin in 20 μg dose has significantly (P < 0.05) increased estrus rate (86.96%) ovulation rate (82.61%) and conception rate (65.22%) among other doses when combined with mifepristone (0.4 mg/kg dose) in cattle. A second experiment was designed to select the best time for FTAI, 95 cows were selected and treated with BPBMH in 0.4 mg/kg mifepristone dose estrus synchronization protocol and timed artificial insemination was performed h 16, 20, 24, 28 and 32 after second Buserelin. The results showed that artificial insemination at 16 h of mifepristone injection was the best insemination time in cattle.