2012 Volume 49 Issue 3 Pages 219-223
Sexual dimorphism of growth and development of organs and tissues in poultry species results from differentiated endocrine system and metabolic processes rate, and leads to difference of skeletal muscles mass and final body weight. Our knowledge on physiological variation in free amino acid status of skeletal muscles in meat-type turkeys is strongly limited. The aim of the study was to determine sex-related differences of free amino acid concentration in breast muscles obtained from turkeys at the age of 20 weeks. The experiment was performed with 34 birds divided into two equal groups consisting of females and males. During whole period of the breeding cycle all birds were kept under identical environmental conditions and had free access to fresh water and feed supplied in accordance to their growth stage. At the age of 20 weeks of life, final body weights of birds were measured and breast muscle samples were obtained. To evaluate free amino acid concentrations in breast muscles, the samples were analyzed with the use of ion-exchange chromatography. Statistical comparison of amino acid concentration in breast muscles of females and males was performed using non-paired Student’s t-test. Final body weight was 27.6% higher in male than in female turkeys. Skeletal muscle concentration of glutamine, tryptophan, serine and asparagine was found to be significantly higher in males than in females, while opposite results were obtained analyzing cysteic acid, taurine and valine. In conclusion this study revealed sex-differentiated final body weight and skeletal muscle amino acid concentrations in turkeys. Improved skeletal muscle metabolism of functional amino acids glutamine and tryptophan in males may be postulated as crucial factors responsible for their higher growth rate and final body weight when compared to females. The obtained results may serve to optimizing feed for turkeys and their systemic development.
