Skeleton growth and musculoskeletal ratio in Cornish chicken
The paper presents the results of studying the growth of skeleton as a whole and its separate parts in the Cornish chicken (from hatching to 420 days of age). The comparative mass of skeleton and its parts in the process of ageing for the most part decreases. The authors show changes in the skeletal structures mass in different periods of postnatalontogenesis. The growth of skeleton and its parts features, as a rule, negative allometry, sometimes close to isometry, and a high coefficient of determination in all indices.The body axial skeleton bones grow in fact with the same rate (b = 0,94-0,96). The shoulder-girlde skeleton, in compliance with the previous data, grows faster than the body weight, that has positive allometry (P<0,01). This concerns two bones: clavicle (b = 1,10; P<0,01) and coracoid (b = 1,05; P<0,01). The shoulder blade (scapula), according according to the obtained data, grows isometrically. The findings provide grounds for deterrmining thesignificance of bones in connection with chicken dimensions and mass. The high growth of body axial part muscles, which are mainly located in the breastbone and shoulder area,require more spacious area for thier attachment.For the most part, they are attached to the clavicle and the caracoid, which proves the necessity of the intensive growth and development of these two bones. Although a sufficiently large number of muscles are attached to the shoulder blade, the area of their attachment is not large. This may be the reason for the isometric growth of the shoulder blade. The study has revealed the correlation of muscles and bones in different parts of chicken bodies at the end of their growth (up to the chicken mass of 4990 g). The thoracic part is the most carneous (the muscles occupy up to 95-96%). The second place belongs to the haunch (muscles - 90%, bones - 10%). The shoulder and crus have lower commercial value: only 2/3 of their mass are muscles. The outermost part of the body - the manus - has very low commercial value: it contains 3,3-3,5 times less muscles than the thoracic part. The wings are 24% less fleshy than the legs. The authors make a conclusion that it is necessary to strengthen the chicken skeleton not by mass increasing but as a result of its structural changes.