Reproductive performance, semen quality, and fatty acid profile of spermatozoa in senescent broiler breeder roosters as enhanced by the long-term feeding of dried apple pomace

Avian spermatozoa are characteristically high in polyunsaturated fatty acids which predispose them to lipoperoxidation, thereby diminishing their fertility. As a by-product, well-known for antioxidative properties, dried apple pomace (AP) was fed to aging Ross 308 breeder roosters (n=80) at the dietary inclusion levels of 0 (AP0), 10 (AP10), 20 (AP20), or 25 (AP25) percent for 14 consecutive weeks. Seminal traits were studied every other week. At the end of the trial, sperm fatty acids profile, seminal plasma total antioxidant capacity (TAC), fertility, hatchability, and hatchling quality were evaluated, using 240 artificially-inseminated young hens. Dietary AP increased sperm motility and livability and decreased the seminal content of thiobarbituric acid reactive species. Dietary treatment and age interacted to positively affect sperm concentration and sperm membrane integrity. Feeding AP was associated with an increase in C20:4(n-6), C22:4(n-6), and total unsaturated fatty acids percentages. Birds in the AP25 and AP20 treatment groups respectively showed 6 and 7% increases in fertility rate. Interestingly, a higher hatchability rate was found for AP20 group, associated with a higher number of sperm penetration holes in the perivitelline membrane and a lower rate of early embryonic mortality. However, hatchling quality was not affected by dietary AP. Overall, these data suggest that AP could remarkably improve several sperm characteristics, seminal TAC, fertility, and hatchability rate in aging breeder roosters. These improvements were also associated with a higher content of total unsaturated FA in the sperm plasma membrane. Future studies are needed to disclose the causal mechanisms involved.