Strategy to Increase Summer Fertility?13 January 2015
A hormonal protocol giving treatments before and after insemination could improve summer and autumn fertility, according to a study in the Journal of Dairy Science.
Combined hormonal treatments before artificial insemination - to increase follicular turnover - and progesterone supplementation after insemination were tested in research published in December's edition.
The Dairy Cattle Reproduction Council reports that cows were hormonally treated to induce two consecutive nine-day cycles, with GnRH administration followed by PGF2α seven days later followed by an intravaginal insert containing progesterone on day five post-A.I. for 14 days.
Results indicate that first-A.I. conception rate (CR) data revealed a positive interaction between treatment and cows previously diagnosed with postpartum uterine disease.
Interaction between treatment and low body condition score tended to increase the probability of first-A.I. CR and increased pregnancy rate at 90 DIM and at 120 DIM.
The scientists suggest that when administered with efficient cooling, combined hormonal treatment in specific subgroups of cows, like those previously diagnosed with postpartum uterine disease or those with low body condition score or low milk yield, might improve fertility during the summer and autumn.