Effect of Dietary Betaine and Folic Acid Supplementation on Performance, Egg Folate Content and Egg Production of Japanese Quail

A study was conducted to investigate the effects of different betaine (BET) (0.0, 0.5 or 1.0 g/kg) and folic acid (FA) (0.0, 4.0 or 8.0 mg/kg) levels on performance, egg FA concentration and egg production of laying quails using 288 forty-two day-old Japanese quail in a 3 × 3 factorial arrangement of treatment based on randomized complete design. The results showed that none of the performance traits, except feed intake, was affected by dietary treatments. No effect of FA and BET supplementation was observed for egg spe-cific gravity but egg shape index was affected throughout the experiment. No significant differences were observed for egg white, pH, weight and ratio, but Haugh unit (HU) was affected significantly by FA sup-plementation (P<0.01). High levels of FA supplementation (8 mg/kg) decreased the HU (P<0.01). More-over there was a significant interaction between the FA and BET for HU (P<0.05) and increasing the BET level did not changed the HU at the low and medium levels of betaine, while decreased the HU at the high-est level of FA (8 mg/kg). No effects of FA or BET were observed for egg yolk pH, egg yolk index and egg yolk percentage, but egg yolk FA content (EYFC) and egg yolk color was affected significantly by FA sup-plementation (P<0.01). EYFC increased from a low of 843.87 μg/kg for birds consuming the basal diet with no added FA, up to a high of 1456.25 μg/kg for birds consuming diets with 8 mg/kg of FA.