Abstract: An in vivo experiment was conducted to determine the effect of dietary betaine supplementation as a replacement for methionine on broiler performance and carcass characteristics. Three hundred day old Ross 308 broilers were used in a randomized completely design with 4 treatment and 5 replicates in each treatment and 15 birds/replicates and reared on the floor pens for 42 days. A basal diet was formulated as control according to NRC, recommendations for starter (1-21 days) and grower (22-42 days) periods. In experimental diets, methionine levels were as formulated (control (T1)) and at 90 (T2), 80 (T3) and 70% (T4) of the control. The incompleted levels of the methionine in T2, T3 and T4 supplemented by adding Betafin to the diets. The result of present study indicated that feed intake was no affected by treatments (p>0.05). The birds under T2 and T4 had lower body weight gain during 1-42 days as compared with control group. Also, the using of T4 in both of 22-42 and 1-42 days and T2 in 1-42 days significantly resulted to undesirable feed conversion ratio (p<0.05). Supplementation levels of betafin in diets no significantly (p<0.05) affected the amount of carcass and its cuts (p>0.05), except the percent of thigh was significantly higher than control group (p<0.05).
M. Baghaei, A. Ashayerizadeh, M. Eslami, M. Bojarpour, H. Roshanfekr and K.H. Mirzadeh, 2009. Betaine (Betafin®) Replacement for Methionine in Diet on Growth Performance and Carcass Characteristics of Broiler Chickens. Research Journal of Biological Sciences, 4: 1037-1040.