No abstract

Seventy two cockerels of the 24-week-old Gimmizah strain were used to evaluate performance of Gimmizah cockerels fed two levels of methionine and lysine and two levels of protein. The work in this study was divided into two experiments. 1 st experiment aimed to test two levels of methionine at 0.24 and 0.34% with two levels 12 and 13% CP while 2 nd experiment was designed to test levels of lysine at 0.60 and 0.70% at the same protein levels in factorial design 2×2 in each experiment. Body weight and feed intake were recorded while, the change in body weight, daily protein intake and methionine and lysine intake were calculated. Semen characteristics and some blood plasma characteristics were determined. The experimental period terminated at 40 weeks of age. The obtained results showed that: From results of the first experiment it will be noticed that protein levels had no significant effects on final body weight (FBW), BW change, daily feed intake, daily methionine intake, semen characteristics and fertility percentage but increasing protein level to 13% CP exhibited significant increase in daily protein intake, globulin and AST in blood plasma. Increasing methionine level from 0.24% to 0.34% significantly improved FBW, BW change, daily feed intake, daily methionine intake, fertility percentage, globulin, glucose and semen quality characteristics except for volume which numerically improved. On the other hand daily protein intake, total protein, albumen, AST and ALT in blood plasma were not affected by methionine levels. Interaction effect between protein and methionine levels had significant effects. Cockerels fed diet 0.34% methionine with any protein level resulted in significant improvements in FBW, BW change, daily feed intake, methionine intake, motility%, live sperm, dead sperm, abnormality, fertility percentage and glucose in blood plasma compared with methionine 0.24% level. Interaction between protein and methionine levels was not significant on semen volume, total protein, albumin and ALT in blood plasma. In the 2 nd experiment results revealed that daily lysine intake had insignificant effect on cockerels fed on different protein levels. In contrast cockerels fed diet contains 0.70% lysine displayed significant increases in daily lysine intake compared with those fed diet contains 0.60% lysine. Interaction between studied factors had insignificant affect FBW, BW change, all semen characteristics, fertility percentage, total protein, albumen and glucose in blood plasma but cockerels fed diet contains 0.60% lysine and 13% CP content resulted in significant reduction (P≤0.05) in daily feed intake and lysine intake compared with other treatments. On the other hand cockerels fed diet containing 12% CP with any lysine level recorded significant decrease in daily protein intake than those fed on 13% CP. While there were no significant variations in daily feed intake, daily lysine intake, AST and ALT in response to feeding on diets containing0.70% lysine and 12 or 13% protein levels compared with other treatm...