Effect of dietary lutein on semen quality, reproductive hormones, and oxidative injury products of aged roosters

The present study aimed to investigate the effect of dietary lutein on semen quality, reproductive hormone profiles, and oxidative injury products in aged roosters. A total of 120 Arbor Acres broiler breeder roosters at 60 weeks of age were randomly distributed into 4 different feeding groups with 6 replicates of 5 roosters each. The four diets contained lutein at 0 (CON), 25 (L1), 50 (L2) and 75 (L3) mg/kg of feed. The feeding trial lasted 4 weeks after one week of adaptation. Results showed that compared to CON, dietary lutein increased (P ≤ 0.001) semen volume, sperm density and viability, and decreased (P ≤ 0.019) sperm abnormality. Here L3 was more pronounced (P < 0.05) on viability and abnormality than other lutein groups. Lutein increased (P ≤ 0.001) serum reproductive hormones including testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), dehydroepiandrosterone sulfate (DHEA-S), dihydrotestosterone (DHT), and androstenedione, with L3 showing the best effect on LH, DHT, and DHEA-S. Dietary lutein also increased (P < 0.001) serum lutein contents and lowered (P < 0.001) oxidative injury products including malondialdehyde (MDA), protein carbonyl, and 8-hydroxy 2 deoxyguanosine. Furthermore, a linear (P < 0.05) relationship was found between dietary lutein doses on ejaculate volume, viability, LH, DHT and DHEA-S. In conclusion, dietary lutein can enhance semen quality, maintain reproductive hormone levels and reduce oxidative products. Therefore, it can be used as a dietary supplement to improve the fertility of aged roosters.