Biological value of lamb meat in relation to amino acid composition and genotype differences
2025
Mykolaichuk, L. P. | Lesnovskay, O. V. | Sanzhara, R. A. | Kozyr, V. S. | Gutyj, B. V. | Dochkin, D. O. | Mylostyvyi, R. V.
Lamb meat is widely recognised as a highly digestible source of high-quality protein, rich in essential amino acids vital for human nutrition. Its biological value is largely determined by the amino acid profile, which is influenced by breed, feeding, and management systems. This study aimed to compare the amino acid composition of muscle tissue in purebred Romanov and crossbred Romanov × Hisar ram lambs to assess the effect of genotype on the nutritional quality of meat. The experiment involved ten animals (n = 5 per group), reared under identical conditions and slaughtered at 8 months of age. Amino acid concentrations were determined by ion-exchange chromatography, with tryptophan and hydroxyproline analysed using spectrophotometric methods. The results showed that the crossbred lambs had significantly higher contents of isoleucine (12.7 %, P ≤ 0.001), leucine (8.0 %, P ≤ 0.001), threonine (10.3 %, P ≤ 0.05), lysine (7.5 %, P ≤ 0.05), and aspartic acid (8.4 %, P ≤ 0.01). A reduction in hydroxyproline content by 17.5 % was also observed, suggesting lower connective tissue density and improved meat tenderness. The protein quality index, calculated as the tryptophan-to-hydroxyproline ratio, was 2.98 in the crossbreds versus 2.21 in the purebreds, representing a 35 % increase. These findings indicate a clear improvement in the biological value of muscle protein in crossbred lambs, confirming the positive impact of introducing Hisar genetics into Romanov sheep. Further research is warranted to evaluate how these compositional improvements translate into consumer sensory perception and functional meat properties under different production systems.
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