Metabolisable energy studies with Turkeys: Nitrogen correction factor in metabolisable energy determinations

Metabolisable energy (ME) values, uncorrected for nitrogen retention, for a Canadian rapeseed meal and an American wheat, determined by a regression method with turkey poults, were influenced by the protein content of the basal diet used. 2. Increased nitrogen retention offsets the effect of substituting rape‐seed meal into a low‐protein basal diet, providing a high estimate of ME. 3. The expected offsetting due to nitrogen retention of the effect of substituting wheat into a high‐protein basal diet was not observed but this was due to some unexpected trends in nitrogen retention. 4. Correction of ME values for nitrogen retention decreased differences due to disparities between the protein contents of the ingredients evaluated and the basal diet.