Effect of Method of Determination on Digestible Energy and Nitrogen and on Metabolizable Energy Values of Rapeseed Meal and Soybean Meals Fed to Growing Pigs

Commercial samples of solvent-extracted rapeseed meal (RM), 44% crude protein soybean meal (SM) and 50% crude protein SM were evaluated for digestible energy (DE), metabolizable energy (ME), nitrogen-corrected ME (ME n ) and digestible nitrogen (DN), using two methods of evaluation. A comparison of results from feeding the test meals for two different lengths of time prior to conducting the determinations was also made. Sixteen castrate male pigs were allotted to each of the two evaluation methods, with four pigs assigned to each of three treatment groups, and four pigs assigned to the basal control group for each method. The two SM samples had higher DE, ME, ME n and DN than the RM sample. The DE, ME and ME n values in kcal/g dry matter for RM were 3.37, 3.13 and 2.76, and for SM they we’re 4.42, 4.21 and 3.71, respectively. The overall mean coefficient for DN was 79.2% for RM and 92.8% for SM. There were no significant differences observed between methods or between the two time periods. The values for the basal diets were uniform throughout the trial, as indicated by low standard errors.