Effect of Different Levels of Dietary Crude Protein and Lysine on Litter Composition and Carcass Yield in Female Broilers from Three to Six Weeks of Age

The objective of the present study was to evaluate carcass characteristics and litter quality in female broiler chickens fed variable levels of dietary crude protein and lysine during the grower period (21-42 d). The experimental design was completely randomized. on d 21 of experiment, 4 replicate pens of 12 chicks each were fed 1 combination of dietary lysine and CP (18% CP with 0.8, 0.9, 1.0 and 1.1% lysine and 20% CP with 0.8, 0.9, 1.0 and 1.1% lysine., and 22% CP with 0.8, 0.9, 1.0 and 1.1% lysine) until d 42. Data were evaluated with ANOVA for a complete randomized design, using the general linear models procedure of SAS software. Dietary crude protein and lysine levels had significant effects on body weight gain, carcass yield, breast and leg quarter weight and abdominal fat. In experiments, female broilers had a greater response to supplemental lysine when 18% CP was fed, but less response to supplemental lysine when 20 or 22% CP was fed for BWG, CY, BMW and leg quarter weight. The requirement for lysine at 18% CP (as a percentage of diet) were 1.1% for BWG, CY, BMW and leg quarter weight and at 20% CP were 1.0% for abdominal pod fat. As regards, reducing CP did case litter N, pH and humidity to decline both of these advantages will improve air quality within the poultry house.