PERFORMANCE OF MYOCARDIAL AND BLOOD SERAL CHANGES IN PIGS FED DIETS CONTAINING HIGH OR LOW ERUCIC ACID RAPESEED OILS

Crossbred pigs (80 barrows and gilts), 4-5 wk old and averaging 7.9 kg were fed diets containing 15% rapeseed oil of either high (34.2%) or low (1.2%) erucic acid content, or a control diet to which no oil was added. Tissue samples were taken from the left ventricle of pigs slaughtered after 4, 16 and 23 wk on experiment, at which time they averaged 19, 87 and 130 kg liveweight. Differences in growth rate were not significant for any of the 5 treatments. Feed conversion efficiency was poorest (P < 0.01) for pigs fed the control diet. Significant differences between treatments were detected at 1 or more slaughter weights for serum cholesterol, albumin, alkaline phosphatase, blood urea nitrogen, glucose, protein-bound iodine and serum glutamic oxaloacetic transaminase. Total backfat and area of loin were not significantly affected by either source or level of rapeseed oil. Most of the carcass measurements recorded were significantly (P < 0.01) influenced by sex and slaughter weight. Histological examination of heart tissue from the left ventricle showed no significant effect of rapeseed oil on the incidence of cardiac lipidosis and myopathy.