Influence of humic acid addition to drinking water on laying performance and egg quality in Japanese quails

The experiment was performed to investigate the effect of humic acid to drinking water on the laying performance and quality of eggs in Japanese quails. Hundred and forty, 9-weeks old female Japanese quails (Coturnix coturnix japanica) were randomly designated to four treatment groups forming 5 replicates each containing seven birds. Group I was the control group. Group II, III, IV were administered 250 ml/ton, 350 ml/ton, 450 ml/ton humic acid into drinking water, respectively. The egg characteristics were determined after 8th and 10th weeks of experiment. Addition of humic acid had a positive effect on the live weight change (p < 0.05) and yolk weight (p < 0.01). Egg shell thickness, albumen weight and yolk color were significantly (p < 0.01) lower in the experimental groups than that of control group. However humic acid had no effect on egg production, feed consumption, feed efficiency and other egg quality. In conclusion, data of our study demonstrated that liquid humate applied in drinking water has significantly improved live weight change and yolk weight. The positive effects of liquid humates, possibly related to improved nutrient utilization through various metabolic activities in the body are yet to be further investigated.