European Journal of Zoological Research
Abstract
Author(s): Mohammad Reza Attar Nosrati, Vahab Babapour and Kambiz Nazeradl
The goal of this experiment was to clarify the effects of dietary tryptophan (Trp) on the growth hormone (GH), T3
and T4 in broiler chicks in 0-3 wk. In this study different levels of dietary Trp (0.12%, 0.16%, 0.20%, 0.24% and
0.28%) were used for first three weeks in male broiler chicks. Animal randomly divided into five treatments with
four replicates. Blood samples were collected in 11 and 21 days. Plasma concentrations of GH, T3, and T4 were
measured using ELISA kits. The results showed that reduction in dietary Trp significantly increase concentrations of
plasma GH and T3 in 11 day and 21day (P<0.05). Increase of dietary Trp compared with NRC recommended level
(0.20%Trp) decrease a little level of GH, T3 in two period (P>0.05). Dietary Trp had no significant effect on T4 in
11 day (P>0.05) but reduction of dietary Trp level significantly decrease of T4 level in broiler chicks. Therefore, we
conclude that dietary Trp levels in chicks inversely affected GH,T3 levels in 11, 21dayes and only significantly
affected T4 in 21day.
