Document Type : (original research)
Authors
1
Department of Animal Science, Faculty of Agriculture, University of Jiroft, Jiroft, Iran.
2
Animal Science Department, Faculty of Agriculture, University of Jiroft, Jiroft, Iran
3
Plant Production Department, Higher Education Complex of Shirvan, Shirvan, Iran
4
Department of Animal Science, Faculty of Agriculture, University of Jiroft, Jiroft, Iran
10.22034/AEJ.2021.288597.2544
Abstract
Lysine is the main essential amino acid required for muscle building in poultry and preparation of accurate Lys requirements can greatly affect broiler performance and meat yields. This study was carried out in a completely randomized design with 200 Ross broilers. Experimental treatments consisted of a Control diet with lysine requirement based on Ross Aviagen Recommendation, a diet with 10% lower than lysine requirement, a diet with 20% lower than lysine requirement, a diet with 10% more than lysine requirement and a diet with 20% more than lysine requirement. The effect of treatments on feed intake was not significant. In the grower, finisher and overall phase, increasing lysine level led to improved weight gain and feed conversion ratio (P<0.05) and decreasing lysine level had a negative effect on growth performance. The relative weight of carcass and breast increased by increasing lysine level (P<0.05), while the relative weight of femur and other internal organs was unaffected. The effect of lysine level on blood albumin, total protein and triglyceride was significant (P<0.05), but Uric acid was not affected. Most muscle protein percent and area were observed in broilers fed by high levels of lysine. These results imply that increasing lysine levels of diet 10 or 20% more than Ross recommendation can improve growth performance, carcass and breast relative weight, muscle protein percentage and histopathology of broilers.
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