Effects of DL-methionine and L-methionine sources on performance, internal organ characteristics and blood factors of chicken broilers

Document Type : (original research)


1 Department of Animal Science, Faculty of Agriculture, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran

2 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.