Effects of turmeric (Curcuma longa) powder supplementation in laying hens' diet on production performance, blood biochemical parameters and egg quality traits.

This study aimed to evaluate the effect of turmeric powder (TP) supplementation on laying hens' performance, blood biochemical parameters and egg quality parameters. In total, 144 laying hens (Hy-line W36) ageing 53 weeks were used in this study. Birds were randomly assigned to three treatments (6 replicates, 8 birds in each). The diets contained 0 (control), 0.25, and 0.5% TP based on the maize-soybean meal. It was found that the TP supplementation significantly reduced egg production, weight and mass throughout the experiment (p < 0.05). However, the feed conversion ratio increased (p < 0.05), whereas feed intake remained unaffected. Yolk percentage, height and index reduced, and the yolk colour, accompanied by the egg-shell percentage, increased (p< 0.05) during the first 4 weeks of the experiment. Interestingly, only the albumen pH was affected by TP supplementation during the second 4 weeks (p < 0.05). The serum malondialdehyde level reduced significantly, and the total antioxidant capacity increased in the groups fed on the diets supplemented with TP (p < 0.05). Serum lipids levels, including triglyceride, cholesterol and very-low-density lipoprotein (VLDL), and the yolk triglyceride level reduced due to TP supplementation (p < 0.05). The interactive effect of all three independent factors on the internal quality traits of the stored eggs was significant only for yolk pH (p < 0.05). Thus, TP could be a potential lipid reducing factor, especially triglycerides, and a natural antioxidant in laying hens' diet. However, it may significantly impair the productive performance of laying hens under normal environmental conditions.