Effects of Methionine-Supplemented Low-Protein Diets on Production Efficiency, Heat Resilience, and Welfare of Broilers in Tropical Climates.

BACKGROUND

The feeding strategy is one of the alternatives for countering the harmful effects of heat stress in broilers. This study was carried out to evaluate the effect of low-protein diets supplemented with different levels of dietary methionine on the growth performance and welfare of Cobb500 broilers raised in a tropical climate.

MATERIALS AND METHODS

A total of 500 15-day-old Cobb500 broilers were randomly divided into five treatments with five replicates of 20 chickens each: chickens fed a standard methionine-free diet (ME: 3100.97 kcal/kg) with high crude protein (P) content (18.25%) (T) and low P content (15%) (T) and chickens fed a low P diet (15%) supplemented with methionine at rates of 0.05% (M), 0.08% (M), and 0.1% (M). The trial lasted for 28 days, during which water and feed were provided ad libitum. Growth performance and carcass composition were evaluated. Gait abnormalities and litter quality were assessed at 38 and 42 days of age, respectively. At 45 days of age, blood samples were collected, and the serum was used for biochemical and physiological parameter analysis.

RESULTS

Chickens in the M treatment showed higher growth performance (p < 0.05) than those in the other treatments. The thyroid hormone concentrations were higher (p < 0.05) in the M treatment, and litter quality is good in all birds fed a low-protein diet supplemented with methionine.

CONCLUSION

Methionine supplementation at the level of 0.1% to a 15% protein diet improved the growth performance and welfare of Cobb500 broilers under a tropical climate.