Correlation of protein content of feedstuffs with the magnitude of nitrogen correction in true metabolizable energy determinations [Single Comb White Leghorn roosters]

The relationship between the protein content of feedstuffs and the magnitude of difference between corresponding true metabolizable energy (TME) and nitrogen-corrected TME ( TMEn ) was investigated. Fifty-two samples of feed ingredients, mixtures of ingredients, and mixed feeds were assayed for TME and TMEn . A positive relationship was observed between the protein content of the feed samples and the magnitude of difference between determined TME and TMEn values. The regression equation describing this relationship is Y = . 122X + 3.724, where X equals percent protein and Y the percent difference between TME and TMEn . The corresponding r2 was .60.