Factors Affecting the Metabolizable Energy Value of Rapeseed Meal

INFORMATION on the absorbability of nitrogen from rapeseed meal is limited. Drouliscos and Bowland (1969) reported that the average true digestibility of nitrogen from two samples of rapeseed meal by rats was 78.4%. Using colostomized hens, Kubota and Morimoto (1965) found that the absorption of nitrogen from one sample of rapeseed meal was 72.6%. Determination of the absorbability of nitrogen by avian species is difficult because urine and feces are voided together. In the present studies two techniques were used to overcome this difficulty. These were (1) use of colostomized hens to permit separation of feces and urine so that unabsorbed nitrogen in the feces could be measured and (2) use of the nitrogen remaining in the terminal fifth of the small intestine as a measure of unabsorbed nitrogen. The latter was based on the observation of Imondi and Bird (1965), and Bird (1968) that by the time feed passed…