The Effects of DL-methionine and DL-methionine Hydroxy Analogue on Growth Performance, Contents of Serum Amino Acids and Activities of Digestive Proteases in Broilers

This study was conducted to determine the effect of DL-methionine (Met) and DL-methionine hydroxy analogue (MHA) supplementation on the growth performance, contents of serum amino acids and activities of digestive protease in broiler chicks from 0 to 3 weeks old . There were three treatments in this study: (1) control (basal diet), (2) 0.24% Met supplementation and (3) 0.368% MHA supplementation. The results showed that Met and MHA supplementation did not significantly (p>0.05) improve feed efficiency and body weight gain for broilers from 0-1, 0-2 and 0-3 weeks of age. The serum levels of homocystine, methionine and taurine were significantly (p<0.05) higher with supplementation of Met or MHA than with control. The pepsin activity of proventriculus was increased with (p<0.05) Met supplementation at 21 days of age and with MHA supplementation at 7 and 14 days of age. The trypsin activity was also increased (p<0.05) with MHA supplementation at 7 days of age. The chymotrypsin activity in pancreas and the dipeptidase activity in small intestinal mucosa and content were not affected (p>0.05) by Met or MHA supplementation. (