Production performance, egg quality and some serum metabolites of older commercial laying hens fed different levels of turmeric rhizome (Curcuma longa) powder
This experiment was conducted to evaluate the effects of different levels of turmeric rhizome powder (TRP) on production performance traits, egg quality and some serum metabolites of laying hens. A total of 240 laying hens (Hy-Line W-36) were randomly assigned as a completely randomized design with 5 dietary treatments (0.0 as control group, 0.5, 1.0, 1.5, and 2.0 g kg-1 TRP) and 12 replicates of 4 birds each. The result showed that after addition of different levels of TRP, the feed conversion ratio (FCR) decreased significantly (P<0.05) as soon as expect, after two week of feeding. This reduction was mainly duo to the numerical decrease of feed intake and slight increase of egg mass. Although, TRP had no any significant effect on specific gravity, egg shell weight and egg shell weight:egg weight ratio, but after feeding of the highest level of TRP, the egg shell thickness improved slightly. Also, increasing levels of TRP significantly (P<0.05) increased the yolk colour fan value after 4 weeks experiment. The diets supplemented with TRP markedly (P<0.05) decreased serum triglyceride, total and LDL-cholesterol and increased LDL-cholesterol significantly. The present results suggest that TRP, at the level of 2.0 g kg-1 for two weeks, have strong potential for egg mass increasing, FCR improvement and correction of serum lipid profile.