Abstract
Eighteen growing Awassi lambs were used in this study to determine the effect of supplementing two levels of yeast and methionine (cyc-methionine) on the trace elements bioavailability, growth rate, and general performance. The lambs were divided to three groups. The dietary treatments were the control diet (C), control diet plus 2 g cyc-methionine/lamb/day (T(1)) and control diet plus 4 g cyc-methionine/lamb/day (T(2)).
Lambs fed 2 g/day of cyc-methionine (T(1)) showed a significantly higher (P<0.05) copper, zinc, and cobalt concentrations in liver and meat tissues, but not the same trend in kidney. No significant (P>0.05) effect of time and time x treatment interaction on copper, zinc, cobalt, and manganese concentrations in blood serum, but cobalt and manganese concentration showed significant (P<0.05) change by time. Moreover, a significantly (P<0.05) higher total body gain, average daily gain, dressing percentage, and lower feed conversion were detected in lambs from T(1) compared with the control and T(2) groups.
Feeding 2 g of cyc-methionine to growing lambs increased the net profit by $6.017/lamb and only $3.52/lamb fed 4 g cyc-methionine/day when compared with the control group.
In conclusion, feeding growing Awassi lambs yeast and methionine in a form of cyc-methionine, with a low level of 2 g/day, improve the bioavailability, of copper, zinc, and cobalt by growing lambs and their growth performance. (C) 2007 Elsevier B.V. All rights reserved.