Abstract
Background:
Rising concerns about antibiotic resistance and residues in meat have increased the need for viable alternatives in sustainable poultry production. Curcuminoids exhibit diverse biological activities and are considered potential natural growth promoters.

Aim:
We assessed the effects of the curcuminoids fraction derived from the Ryudai Gold variety of Curcuma longa on growth performance, serum biochemical profiles, and breast muscle composition and quality in broiler chickens.

Methods:
Ninety one-day-old broiler chicks were randomly assigned to three groups (n = 30). All birds received a starter diet for 13 days. From day 14, two groups were provided a grower diet enriched with curcuminoids at doses of 100 and 300 mg/kg of feed, while a third group served as the control. Feed consumption and body weight were measured weekly. At 35 days of age, birds were sacrificed and blood, caecal contents, breast meat, and duodenum were obtained for serum biochemical, gut microbial, and breast meat quality analysis and duodenal histopathology.

Results:
Curcuminoid supplementation at a dosage of 100 mg/kg, there was a significant increase in body weight compared to the control and 300 mg/kg groups. Feed conversion ratio improved in the 100 mg/kg group, whereas dressing percentage was higher in both supplemented groups. Breast meat proximate analysis revealed a significant increase in crude protein, while other components remained unchanged. Curcuminoid supplementation led to a decrease in serum total cholesterol, triglycerides, and LDL levels, while HDL levels increased, with no significant changes in ALT, AST, or creatinine. Meat quality improved, as indicated by increased redness and yellowness and reduced cooking loss. Gut microbial analysis showed dose-dependent reductions in total viable and Escherichia coli counts, while Lactobacillus increased at 100 mg/kg but decreased at 300 mg/kg. Duodenal histomorphology revealed an increase in villus length and breadth coupled with a reduction in crypt depth in the supplemented groups.

Conclusion:
Dietary curcuminoid supplementation at 100 mg/kg feed improved growth rates, feed conversion, carcass yield, meat characteristics, serum lipid profile, gut microbiota, and duodenal morphology in broiler chickens. Our findings suggested that curcuminoids at lower dose may serve as an effective natural feed additive for broilers.

Key words: Broilers; Curcuminoids; Gut health; Lipid profile; Meat quality.