Rapeseed meal as a protein source for growing pigs

Three groups of 17 Yorkshire pigs, from 24 to 98 kg liveweight, were fed on three diets which differed only in the main protein sources. Diet 1 contained Span rapeseed meal (RSM) 17% and pea 5 %, diet 2 RSM 8 % and fish meal 4 %, and diet 3 (control) soybean meal (SBM) 5.5 % and fish meal 4 %. The daily rations were isoenergetic and isonitrogenous, and contained digestive crude protein (DCP), lysine and S-amino acids according to standards. The feeds were steam pelleted, and the pigs were fed using a one-diet system and restrictive feeding. The only clear difference between diets was the poorer palatability of those containing RSM, especially of diet 2. The feeding of groups 1 and 2 was therefore actually unrestrictive. The average daily intake of f.u./pig was significantly (P < 0.01) lower in group 2. Some tail biting occurred in group 2. The growth results were equal for diets 1 and 3, and nonsignificantly poorer for diet 2. The average daily gains of groups 1, 2 and 3 were 813, 788 and 820 g, and the f.u./kg gain 2.74, 2.78 and 2.74, respectively. In carcass characteristics there were no differences between diets: the side fat was 20.3, 21.3 and 20.9 mm, and the area of l. dorsi 36.7, 37.8 and 37.7cm2, respectively. No odd tastes in fat or meat were observed. The results indicate that quite a high level of Span ROM in steam pelleted diet can be fed and still produce high daily gain. The combination of RCM with other feed ingredients seems to have an extra influence on the palatability and nutritive value of the diet. Because RSM makes the diet more bulky and less palatable, the pigs can be fed ad libitum without negative effect on the carcass quality