Document Type : (original research)
Department of Animal Science, Faculty of Agriculture, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran
Department of Animal Science, Faculty of Agriculture, Razi University, Kermanshah, Iran
The present experiment was performed to investigate the effects of two sources of DL-methionine and L-methionine on the performance, characteristics of internal organs and blood factors of broilers. A total of 400 one-day-old male broilers of Ross 308 strain were divided into 8 treatments and 5 replications (10 birds per replication) in a completely randomized design. Experimental treatments included 1, 2, 3, 4) basic diet + 25, 50, 75, 100% DL-methionine and 5, 6, 7, 8) basic diet + 25, 50, 75, 100% L-methionine. The results showed that in the L-methionine groups, the improvement in performance was related to 75 and 100%, but in the DL-methionine groups, the improvement was seen only in the amount of 100% (P<0.05). The percentage of internal organs in none of the treatments was significantly different (P<0.05). Differences in different sources and levels of methionine had no significant effect on blood factors in broilers (P<0.05). The results of this experiment showed that 75% of the recommended L-methionine of Ross 308 can have a similar result in terms of performance with 100% of the recommended DL-methionine.