Antral follicle count in cattle: advantages, challenges, and controversy
Morotti, FábioZangirolamo, Amanda FonsecaSilva, Nathalia Covre daSilva, Camila Bizarro daRosa, Camila OliveiraSeneda, Marcelo Marcondes
The antral follicle count (AFC) represents the number of follicles visualized by ultrasonography in the ovaries. Antral follicle count tends to be variable among cows but with high repeatability within the same individual. In the last decade, AFC has been considered a biological marker of fertility with many positive aspects of reproductive efficiency for those animals with high AFC. For instance, a larger number and better-quality embryos, better pregnancy rates, increased concentrations of circulating progesterone, in addition to other characteristics linked to fertility, are all responses observed in individuals with high compared with those with low AFC in Bos taurus cattle. However, the positive association between AFC and fertility did not follow the same pattern for Bosindicus. Recent articles showed no connection between fertility and number of antral follicles or better reproductive efficiency for high AFC group in Zebu cows. Thus, the aim of this review is to discuss the various data concerning AFC between indicus and taurus cattle. Additionally, we consider AFC to be a possible tool to improve cattle performance in reproductive biotechnology.(AU)
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