Abstract
Effects of restricted feeding and refeeding on the growth of chick muscles were investigated by measuring fiber diameter, DNA per muscle, total N per DNA and protein composition. The amount of feed intake by chicks was extremely restricted so as to maintain their day-old body weight, and recovery growth was induced by refeeding after restriction for 12 days. Recovery of muscle weight, muscle fiber diameter and total DNA per muscle after refeeding was rapid for the first 6 days of the recovery period and thereafter the recovery rate decreased. On the other hand, total N per DNA was recovered approximately at a constant rate through the experi-mental period. It was consequently assumed that the rapid increase in muscle weight for the early period after refeeding was mainly due to the accumulation of the nucleo cytoplasmic unit with the slight increase in the value of cytoplasm per nucleus. The concentration of sarcoplasmic-protein N was recovered immediately after refeeding, followed by fibrillar-protein N. Extracellular-protein N seems to be hardly affected by the nutrition level.
