METABOLIZABLE ENERGY CONTENT OF TOWER AND CANDLE RAPESEEDS AND RAPESEED MEALS DETERMINED IN TWO LABORATORIES

Abstract

True metabolizable energy (TME) of soybean meal and rapeseed products was determined in two laboratories by feeding the ingredients singly or mixed with a basal diet. Apparent metabolizable energy (AME) was also determined on the same samples and the values compared with TME. TME results between the two laboratories agreed well for the soybean meal and rapeseed meals obtained either by feeding the ingredients alone or with the assay diet, but with whole rapeseeds there was wide disagreement. This was due to poor and variable utilization of the whole seeds by birds in the two laboratories. AME values for the whole rapeseeds were considerably lower than expected, but the values for the rapeseed meals were as anticipated. Grinding significantly (P < 0.01) increased the AME of Tower and Candle rapeseed and the TME of Candle rapeseed. Tower and Candle rapeseed meals did not differ significantly in TME or AME; nor were there differences in the ground seed of the two cultivars.