Effects of Betaine Supplementation to Methionine Deficient Diet on Growth Performance and Carcass Characteristics of Broilers

Abstract

Problem Statement: The efficacy of Methionine (Met) sparing effect of Betaine (BET) has been shown to be associated with dietary compositions, animal physiological stage and living conditions. This study was to determine the extent to which dietary Met could be replaced by BET in broiler chickens under the feeding conditions specific to Chinese poultry industry.Approach: A total of 900 day-old Arbor Acres broiler chicks were fed three corn-soybean meal-based starter rations (d 1-21) and grower rations (d 22-42) for a total of 42 days. Met levels in the diets were: Diet 1, Met content at the recommended level (Control); diet 2, Met level at 85% of the Control supplemented with BET at the level of 400 (starter) or 300 (grower) mg kg^-1 DM; Diet 3, Met level at 75% of the Control supplemented with BET at the level of 600 (starter) or 500 (grower) mg khg^-1 DM. The broilers were raised in a temperature controlled house with 3 pens (replicates) per dietary treatment. Results: In general, treatment had no effect on body weight, feed intake or feed efficiency. Concentrations of growth hormone and insulin-like growth factor-1 in the serum of broilers fed Diet 3 were higher (p<0.05) than that of broilers of other treatments. Supplementation of BET at the level of replacing 25% of total Met increased (p<0.05) breast meat yield and protein content of breast meat and liver, but decreased (p<0.05) abdominal fat yield and ether extract content of liver. Conclusions/Recommendations: Supplementation of BET to replace up to 25% of total dietary Met did not affect the growth performance but improved the carcass quality of the broilers. BET could be used to spare 25% of the total Met in broiler diet that was formulated based on the Feeding Standard of China.