RESUMO
The reproductive performance of broiler breeder chickens noticeably decreases toward the end of their commercial lives. Herein, we determined the effects of vitamin E and selenium dietary supplementation on semen traits, egg fertility (defined as fertilization and hatching rates) of adult (49-week-old) and older (63-week-old) Red Cornish breeders. We found that both vitamin E and selenium were concentrated in the liver and adipose tissue of adult and older Red Cornish breeders, and were transferred to the semen and egg yolk, respectively, in proportion to the level of supplementation. Vitamin E supplementation, in particular, improved ejaculate volume, total sperm count, sperm motility, and viability in both adult and older roosters, whereas selenium improved sperm motility and viability in the adult roosters. Egg fertility increased following supplementation with either vitamin E or selenium. The hatching rate also improved by both supplements in proportion to the level of supplementation. No significant synergistic effects of vitamin E and selenium were found. The levels of egg fertility and sperm trait improvements diminished with the age of the birds and depended on vitamin E and/or selenium doses. Thus, as dietary vitamin E and selenium supplements improved semen quality and egg fertility in these older Red Cornish broiler breeders, such birds could be maintained in flocks to prolong their reproductive output.
