Digestible and Metabolizable Energy Values for Rapeseed Meals and for Soybean Meal Fed to Growing Pigs

Twelve samples of rapeseed meal (RM) and one sample of soybean meal (50% protein) (SM) were evaluated for digestible energy (DE), metabolizable energy (ME), nitrogen-corrected ME (ME n ) and digestible nitrogen (DN). RM samples were of Brassica campestris and B. napus origin and contained meals processed by solvent, prepress-solvent or expeller processes. Two of the meals were from rapeseeds not in commercial production, one a Bronowski (low glucosinolate) napus meal and one a meal from zero-erucic acid rapeseed of napus type. Energy studies were conducted with 64 pigs at 16, 33 and 65 kg liveweight, adding 25% by weight of the test ingredient to the total diet. The overall means and standard errors for all weight groups for gross energy (GE), DE, ME and ME n , in kcal/g of dry matter, for 10 RM (excluding Bronowski and zero-erucic acid RM) were 4.74 ± 0.12, 3.21 ± 0.18, 2.89 ± 0.19 and 2.64 ± 0.19, respectively, while the values obtained for SM were 4.81 ± 0.08, 4.21 ± 0.16, 3.92 ± 0.17 and 3.64 ± 0.16. There were no significant differences in DE, ME or ME n among the 12 RM samples, or between weight periods. The values for the basal diet were uniform throughout. The overall mean coefficient for DN was 75.9% for RM and 89.2% for SM. The DE, ME and ME n values for RM should be considered as being species specific.