Effect of folic acid supplemented feed on metabolic and redox balance, and sperm movement in silver catfish (Rhamdia quelen) males.

Broodstock nutrition influences gamete and offspring quality. Folic acid plays a role in metabolism, redox balance, growth and reproduction potential of males that can affect serpm quality. We fed male silver catfish (Rhamdia quelen) with diets supplemented with folic acid and evaluated its effects on growth, blood parameters, redox balance, proximate composition, fatty acid deposition, testis and liver histology, and seminal characteristics of both fresh and cryopreserved semen. A total of 720 juveniles were housed into 24 net cages. Fish were fed over 300 days with rations containing 347.5 g crude protein kg-1, 12.98 MJ digestible energy kg-1 and supplemented with 0.00, 0.75, 1.50, 2.25, 3.00, and 3.75 mg folic acid kg-1. During the reproductive season, fresh and cryopreserved semen quality and redox balance were assessed. Thirty days after semen collection, the male's growth, blood parameters, blood and testis acid folic contend, and the testis and liver fatty acids profile, redox balance and histology parameters were assessed. The centesimal composition from several tissues were assessed as well. The redox balance parameters were improved at greater folic acid levels. Fatty acid profile and blood parameters were also affected by rations. Males fed 3.00 mg folic acid kg-1 produced the most motile fresh or cryopreserved spermatozoa, as well as the faster cryopreserved spermatozoa. In conclusion, the 3.00 mg folic acid kg-1 ration supplementation is advantageous because enhance the male metabolic status and improve the fresh or cryopreserved spermatozoa quality.