The effect of growth on the composition of avian muscle

Abstract

Pectoral muscle from Rhode-Island Red cockerels at 0, 2 1/2, 4 and 27 weeks of age were analysed for water, chloride, Na, K, P, and Mg, and the total N was divided into non-protein, sarcoplasmic-, fibrillar- and extracellular-protein N. The amounts of water, chloride, Na, and extracellular-protein N/kg decreased and those of K, P, and Mg increased during the first 2 1/2 weeks. K and P fell from this age to a lower level in the adult. The fibrillar proteins was between 2 1/2 and 4 weeks. At 4 weeks the muscle had an almost adult composition. Calculations showed that the increase in the proportion of the cellular phase was accompanied by an increase in the amount of protein N/l of cell water, whereas the amount of Na plus K/l of cell water decreased. The possible influence on cell composition of the uneven distribution of cellular constituents is briefly discussed.