Dietary betaine supplementation improves growth performance, digestive function, intestinal integrity, immunity, and antioxidant capacity of yellow-feathered broilers

To investigate the effects of dietary betaine supplementation on the growth performance, digestive function, intestinal integrity, immunity, and antioxidant capacity of yellow-feathered broilers, a total of 400 one-day-old female yellow-feathered broilers were randomly allocated into 5 dietary treatments with 8 replicates of 10 chicks each, and fed a basal diet supplemented with 0 (control group), 125, 250, 500 and 1000 mg/kg betaine for 74 days, respectively. During the 1–37 days and 1–74 days, betaine linearly increased (p