Effect of Feeding a Low Crude Protein Diet on Growth Performance of Finishing Pigs at a High Ambient Temperature

Abstract

The effects of reducing dietary crude protein (CP) in a high temperature environment (32ºC) on growth performance and back fat deposition were investigated in finishing pigs. Twelve barrows (80.9 ± 7.6 kg) were allotted randomly to two dietary regimens (13.9% CP vs 11.8% CP) and were fed the diets for 4 weeks. The low-CP diet (11.8% CP) was supplemented with amino acids to meet the nutritional requirements. At the end of the experiment, back fat thickness, plasma urea nitrogen, and amino acid concentration were measured for all the barrows. The dietary CP level did not have any effect on growth performance, back fat thickness, or the plasma urea nitrogen concentration of the finishing pigs. Plasma free lysine, threonine, and methionine concentrations were higher in pigs that were fed the lowCP diet. These results indicate that reducing dietary CP by two percentage points does not alleviate the negative effect of heat stress and may not affect fat deposition.