Rapeseed Meal as a Protein Supplement in the Diet of Growing and Fattening Pigs

SUMMARY Two experiments were carried out with growing pigs in which diets containing 10% rapeseed or mustardseed meal were compared with one containing soyabean meal. The diets were all similar in nutrient content and satisfied current requirement values. The rapeseed meals, from Brassica napus , had large potential oxazolidinethione contents, 8 · 4 mg/g in Expt. 1 and 8 · 7 in Expt. 2; none was detected in the mustardseed meal. There were no food refusals in any treatment groups and rates of live weight gain were equally good for rape and mustardseed meal diets as for the control soyabean diet. Carcass quality, assessed by ultrasonic measurements in Expt. 1 and by direct carcass measurements in Expt. 2, was not significantly affected by the presence of rape- or mustardseed meal in the diet. The goitrogenic activity of the rapeseed meal diet, assessed in Expt. 2, was large but this had no discernable ill-effect on production, health or behaviour of the animals.