New dimensions on maternal and prepubertal nutritional disruption on bull fertility: A review.

Earlier, it was said that a bull is half of the herd because of its half contribution towards the genetic makeup in each subsequent generation. Nowadays, bulls are considered more than half of the herd because of the extensive use of frozen semen samples in artificial insemination. Bull's low fertility accounts for a major economic loss to livestock farmers. It is well known that fertility is a low-heritable trait governed by many factors such as genetics, epigenetics, climate, stress, and physical soundness. Apart from all these factors, the nutritional status of the bull also affects the semen quality. It has been seen that a bull given undernutrition at an early age is affected by androgen synthesis and semen quality. The nutrition given to the pregnant dam also affects the male progeny's postnatal semen quality. However, more studies are needed to elucidate the effect of periconception nutrition on the fertility of progeny as far as bulls are considered. This review focused on the effect of maternal undernutrition during the periconception period and undernutrition during the early growth phase of bull calves on the postnatal fertility of bulls.