Improving the net present value by estrus synchronization in non-pregnant dairy cows detected by ultrasound 25 days after artificial insemination

Abstract

Pregnancy rates in Holstein cow showed a substantial decline in the past years, which caused intensive estrus synchronization programs for non-pregnant cows to shorten the period between an unsuccessful artificial insemination (AI) and the next attempt on the same cow. The program implied estrus synchronization of non-pregnant cows with either prostaglandin or GnRH followed by prostaglandin after 7 days, then GnRH 2 days later and AI during the following day. Cows included in the estrus synchronization program recorded an improvement of the pregnancy rate at 130 days in milk compared to those in which this strategy was not applied (56.7% vs. 37.5%; P<0.05). The economic analysis revealed a difference in the net present value (NPV; $/cow/year) of $10.1/cow/year between the two programs (rebreeding the non-pregnant cows following estrus synchronization program and AI at detected estrus vs. AI at detected estrus). In summary, rebreeding the non-pregnant dairy cows after early negative pregnancy diagnosis (25 days after AI) using estrus synchronization program can improve the pregnancy rate and economic value of dairy farms.