RESPONSE OF EARLY WEANED PIGS TO DIETS OF DIFFERENT DIGESTIBLE ENERGY CONCENTRATIONS AND THE EFFECTS OF CEREAL SOURCE AND ADDED MOLASSES ON PERFORMANCE

Abstract

One hundred and sixty pigs weaned at 2 weeks were allotted at an average initial weight of 3.8 kg to two experiments to examine the effects of diets based on barley or wheat as the cereal component and having digestible energy (DE) concentrations ranging from 2.8 to 3.6 Mcal/kg. Protein was in constant ratio to DE (15.2 kcal DE/g protein). Very high mortality was experienced on the lower energy levels, although the inclusion of 5% molasses in the formulation reduced mortality. Among surviving pigs, growth rate was significantly reduced at lower energy concentrations. The optimum DE level for maximum gain was 3.2 Mcal in the first experiment and 3.4 Mcal/kg in the second. The efficiency of utilization of DE for growth was best at a DE concentration of 3.2 Mcal/kg in the first experiment but did not vary in the second. Digestibility of dietary protein increased with increasing dietary DE but nitrogen (N) retention as percentage of N intake or of digestible N was not significantly influenced by DE in the diet.