Postpartum follicular and luteal activity in Hoistein-Friesian cows genetically selected for high or low mature bodyweight: Relationships with follicle stimulating hormone, insulin, insulin-like growth factor-1 and growth hormone.

The article focuses on the study to investigate ovarian follicular and luteal activity during the postpartum period of cows that are genetically selected for low or high mature body weight, in relation to reproductive endocrine parameters to determine the occurrence of differences between strains that could affect fertility outcomes. The results indicate that the heavier cows had shorter intervals than light strain cows from calving to the emergence of the first and second dominant follicles. Also it was found that the concentrations of follicle stimulating hormone in heavy strain cows before the emergence of the second, third and fourth dominant follicles are comparatively higher. It is concluded that there is an earlier emergence of dominant follicle and ovulation in the heavier cows