Effects of incremental dietary turmeric rhizome meal on the production performance, egg quality, vitellus nutritional composition, and health biomarkers in Isa Brown hens

The global push toward antibiotic-free food animal production necessitates the evaluation of natural feed additives that can enhance bird health and egg nutritional composition. This study investigated the effect of turmeric rhizome meal (TRM) on production performance, egg quality, vitellus nutritional composition, and health biomarkers in Isa Brown hens. A total of 160 healthy 23-week-old Isa Brown hens (1888 ± 11.6 g body weight) were randomly allocated to 4 groups with 20 replicates of 2 hens each. The control group received a basal diet, whereas TRM3, TRM6, and TRM9 received basal diets supplemented with 3, 6, and 9 g TRM/kg diet, respectively, for 84 days. Results indicated significant quadratic effects for mean final body weight ( p = 0.032), mean daily feed intake ( p < 0.001), mean number of eggs laid per hen ( p = 0.002), and mean hen day egg production ( p < 0.001). Moreover, linear effects ( p < 0.001) were recorded for lysine, methionine, and linoleic acid contents of the vitellus in response to incremental dietary TRM. Neither linear nor quadratic effects ( p > 0.05) were observed for all evaluated health biomarkers. However, incremental dietary TRM linearly increased ( p = 0.004) the ratio of feed intake to egg weight. These results imply that TRM can be supplemented in layer diets at levels up to 7.6 g/kg without compromising production performance or health biomarkers, while also improving vitellus nutritional content.