Abstract
1. The influence of feeding a high protein diet containing 400 g crude protein (CP)/kg on liver and breast muscle protein synthesis in chicks was investigated using a large dose injection of l‐[4 ‐3H]phenylalanine.
2. Liver weight of chicks fed on the high protein diet was significantly heavier than that of chicks fed on a control diet with 200 g CP/kg, and breast muscle weight was not affected by the treatment.
3. Fractional and absolute protein synthesis rates, RNA and protein contents, and RNA:protein ratio of breast muscle were not influenced by feeding the high protein diet.
4. Feeding the high protein diet decreased fractional synthesis rate of liver protein, an observation explained by reduced RNA:protein ratio. Liver protein content was elevated by feeding the high protein diet and this resulted in no change in the absolute synthesis rate of liver protein.