Factors Affecting Estimates of Metabolizable Energy Values of Rapeseed Meal for Poultry

Estimates of the metabolizable energy values of rapeseed meal are more variable than of other feedstuffs. Supplementation of diets containing rapeseed meal with the antibiotics oleandomycin and bacitracin sometimes increased, and sometimes decreased, the estimates of metabolizable energy. The feeding of rapeseed meal resulted in increased intestinal weights except when the diet was supplemented with antibiotic. It was concluded that the effect of rapeseed meal in limiting utilization of dietary nutrients is mediated through modification of the intestinal microflora. Variations in response to rapeseed meal may accordingly be due to differences in the dominant microflora present in the digestive tract of the birds.