The response of early-weaned pigs to various protein levels in a high energy diet

Abstract

SUMMARYThirty-six male piglets weaned at 20 days of age were allocated to an initial slaughter group and to five dietary treatments with proteinlevels of 15·0, 17·2, 19·1, 21·4 and 23·2% crude protein at a common energy level of approximately 3·6 Meal digestible energy/kg. All diets were offered ad libitum and growth response was compared between 5 and 20 kg and 10 and 20 kg live weight. In both periods there were significant improvements in growth and the food conversion ratio from 15·0 to 17·2%, and 17·2 to 19·1% crude protein. Between 10 and 20 kg live weight dietary protein levels above 19·1% were associated with a depression in growth. Carcass protein increased and ether-extractable material decreased with increased dietary protein over the entire range studied. Retention of digestible nitrogen was maximized on the lower protein diets. Conversion of food into carcass lean was maximized on the two highest protein diets.