EVALUATION OF MEALS FROM LINOLA TM LOW-LINOLENIC ACID LINSEED AND CONVENTIONAL LINSEED AS PROTEIN-SOURCES FOR GROWING PIGS

Two experiments were conducted to determine the nutritional value of Linola(TM) low-linolenic acid linseed meal relative to conventional linseed or soya-bean meals for growing pigs. In the first, the digestible energy content of the meals was determined. In the second, the growth performance and carcass characteristics of pigs given either Linola meal, linseed meal or soya-bean meal as the major protein concentrate in wheat-based diets were evaluated between 20 and 45 kg live weight. The digestible energy concentration (mean +/- SEM, MJ kg-1, air-dry basis) in the three meals was: Linola meal, 9.8 +/- 0.52; linseed meal, 9.4 +/- 0.42; soya-bean meal, 13.0 +/- 0.85. Pigs given diets containing 300 g kg-1 Linola meal or linseed meal ad libitum over the 20-45 kg growth phase had lower feed intakes and grew more slowly (P < 0.05) than those given soya-bean meal. Killing-out proportions were lower (P < 0.001) for pigs given Linola and linseed meals than for those given soya-bean meal. As a consequence, feed conversion ratios on a carcass basis were significantly higher (P < 0.05) for pigs given Linola and linseed meals. The depth of backfat at the P2 position was similar for pigs on all meals (P < 0.05). Pigs given Linola or linseed meals had lighter kidneys, pancreas and spleen (P < 0.05). However, there were no differences (P > 0.05) in the weights of the livers from the pigs from the three treatments. The results indicate that Linola meal is similar in nutritional value to linseed meal for growing pigs. The lower performance of the pigs given these two meals relative to those given soya-bean meal may have been the result of the presence of an anti-nutritional factor(s) that depressed pig performance.