Chrysin-induced sperm parameters and fatty acid profile changes improve reproductive performance of roosters

Having antioxidant and androgenic effects, Chrysin was orally administrated to roosters and reproductive performance including sperm quality and fatty acid composition, testis index, fertility and hatchability rates as well as blood testosterone concentration were assessed. Twenty eight 40-week-old Ross 308 roosters were individually housed, equally divided into four groups and received different levels of capsulated Chrysin including 0 (Ch0), 25 (Ch25), 50 (Ch50) or 75 (Ch75) mg/bird/day for 12 consecutive weeks. Body weighting as well as semen and blood sampling were weekly done from 1^st-10th weeks. A total of three artificial inseminations were carried out on the last two weeks of trial and collected eggs following second insemination were allotted to evaluate fertility and hatchability rates. Sperm fatty acid composition was determined using samples from 12th week. At the end of experiment (12th week) all roosters sacrificed, testis were carefully removed and testis index was calculated. Except for body weight, testis index, sperm abnormality percentage and ejaculated volume, other traits were significantly affected by Chrysin treatment. Sperm total and forward motility, plasma membrane integrity and functionality, semen concentration as well as fertility and hatchability rates were significantly higher in both Ch50 and Ch75 groups compared to control group. In spite of an increasing trend in most of n-3 and n-6 fatty acids, the n-6/n-3 ratio was significantly decreased in both Ch50 and Ch75 compared to other groups. Malondialdehyde concentration was also significantly decreased in Chrysin treated groups compared to control group. Blood testosterone level was only significantly higher in Ch75 group than that other groups. In conclusion, Chrysin administration particularly at higher levels alleviates post-peak fertility reduction in roosters; however, further research are needed to disclose involved mechanism(s).