The Effects of Various Fat Supplements on the Nutritional and Pathogenic Characteristics of Diets Containing Erucic acid in Ducklings

Abstract

Diets containing rapeseed oil (RSO), or RSO supplemented with olive oil (OLO, rich in oleic acid), safflower oil (SAF, rich in linoleic acid) or tallow (TAL, comparatively rich in palmitic acid) were compared for their nutritional and pathogenic characteristics in ducklings. Unsupplemented RSO and the mixtures RSO-OLO and RSO-SAF caused growth retardation, mortality, lipidosis of the spleen cirrhotic changes of the liver and vacuolar changes of the heart and the skeletal muscles. The mixture RSO-TAL caused no mortality and a better growth. It also improved the liver and spleen morphology and decreased the hydropericardium incidence but did not markedly alter the incidence or severity of the vacuolar changes of the myocardium and skeletal muscles. In another experiment the effects of supplementing diets isocaloric in fats and in erucic acid with increasing levels of hardened palm oil (HPO) or glyceryl trilaurate (GTL) were investigated. Increasing levels of HPO increased growth and decreased the incidence and severity of liver cirrhosis, hydropericardium and splenic lipidosis. The vacuolar changes of the skeletal muscles were not improved, but those of the myocardium became severer. The supplement of GTL augmented all lesions, decreased growth and increased mortality. It is concluded that the nutritional and pathological properties of RSO in ducklings are determined both by the excess of erucic acid and the deficit of palmitic acid in the oil.