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Amino Acid Profile of Protein from Pelvic Limb Long Bones of Broiler Chickens

The objective of the study was to determine the amino acid profile in protein from long bones of the pelvic limb (femur, tibiotarsus) in ROSS 308 hybrid broiler chickens, and to examine whether it is sex-dependent. The study material was obtained from 120 Ross 308 broiler chickens (60 males and 60 females) at the end of the fattening (40 days of age). The average weight of birds was 2 694 ± 32.6 g for cockerels and 2 345 ± 23.9 g for pullets. The study birds did not show any clinical signs of leg diseases. The long bones of the right pelvic limbs (femur and tibiotarsus) were collected after bird slaughter and after removal of soft tissues, they were used for laboratory analyses. The crude protein content and the amino acid (AA) composition were determined and the obtained values were recalculated to 100% dry matter. The chemical score (CS) and the essential amino acid index (EAAI) were calculated for each AA. As a standard, the hen egg ovalbumin was used. The crude protein content in 100% dry matter shows that the content of crude protein was significantly higher (P ≤ 0.01) in the femur (405.3 ± 17.21 g/kg) compared to the tibiotarsus (393.5 ± 12.68 g/kg). The same trends were found with regard to sex. Both males and females had significantly (P ≤ 0.01) higher crude protein content in the femur (406.6 ± 19.34 g/kg and 404.1 ± 15.09 g/kg, respectively) than in the tibiotarsus (395.0 ± 12.16 g/kg and 392.1 ± 13.21 g/kg, respectively). Both bones showed the highest contents of Gly, Glu and Pro, and the lowest contents of Met, Tyr and His. The same trends were found with regard to chicken sex. Collagenous protein has lower contents of most AA in comparison to the standard protein – ovalbumin ; especially contents of Ser, Val, Met, Ileu and Phe are substantially lower. On the other hand, collagenous protein had higher contents of Gly, Pro, His and Arg. The collagenous protein EAAI for the femur and the tibiotarsus was 59.0% and 57.4%, respectively. The knowledge of amino acid composition in protein from long bones of the pelvic limb in broiler chickens is important because it can help us understand the origin of bone disorders.

Femur; tibiotarsus; crude protein; chemical score; essentials amino acid index

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