An Increase in Quail’s Egg Lysozyme via Dietary Amino Acids Supplementation

Document Type : Research Paper


1 Former Graduate Student, Poultry Science Department, Tarbiat Modares University

2 Assistant Professor, Poultry Science Department, Tarbiat Modares University

3 Assistant Professor, Nanobiotechnology Department, Tarbiat Modarres University


Lysozyme is one of the bioactive components of eggs with well known antibacterial potential, widely used in food industry, medicine and pharmaceutics. In this study, the possibility of quail’s egg lysozyme concentration and activity (modified via amino acids dietary supplementation) was investigated. In accordance with lysozyme amino acids profile, four amino acids of: asparagine, arginine, glycine, and methionine were added to layer quails’ feed. For supplementation of amino acids, provision of the same level of protein content in all the groups was considered, so that amino acids were supplemented in such a way as to add 0.235% protein to the basal diet. A total of 72 Japanese quails were employed in a completely randomized design experiment of six experimental groups, three replicates and four birds in each of the 18 cages. Amino acids supplementation was proved to have significant increasing effect on egg number and on total egg,s mass production (P<0.05). Feed conversion ratio did not significantly differ among the experimental groups, but the most desirable ratio was observed in the control group. Egg shell weight, percentage of albumen, percentage of yolk, albumen height, Haugh unit and yolk height showed significant differences among the experimental groups (P<0.05).  Supplementation of amino acids to the diet improved these parameters of eggs. Lysozyme activity was assessed via lysoplate and turbidity methods. Supplementation of arginine and asparagine alone and in their combinations increased the lysozyme activity as evaluated by lysoplate (P<0.05) and by turbidity (P<0.05) methods. Lysozyme concentration was also influenced by a supplementation of the mentioned amino acids (P<0.05).