The effects of dietary folic acid and methionine administration on yolk and serum 5-methyltetrahydrofolate and zinc content and quantity of homocysteine on the laying hens serum

This study was performed to evaluate   the effects of folic acid (FA) and methionine (Mt) administration on egg 5-methyltetrahydrofolate (5-MTHF) content, levels of zinc in yolk and serum and concentration of homocysteine on Hy-line W36 hens from 20 to 26 weeks of age. The experiment was conducted as a 4×4 factorial arrangement of treatments in randomized complete design with four levels of Mt (0.25, 0.32, 042, 0.48 mg/kg of diet) and four levels of FA (0, 5, 10, 15 mg/kg of diet). Fortification of laying hens diets with FA 0, 5, 10 and15 mg/kg of diet increased 5-MTHF into yolk significantly (p<0.05). 5-MTHF content of egg was also significantly affected by FA×Mt interaction (p<0.05). FA significantly reduced Zn level of egg and serum (p<0.05), but Mt did not have any effect on Zn content in egg. Levels of serum homocysteine were significantly reduced by fortification of diet by FA (p<0.05).Supplementation of laying poultry diet with FA and Mt could improve the content of yolk 5-MTHF.