Effects of giving a fat-free diet for up to 10 weeks on the male weanling rat

When weanling rats are reared on a fat-free diet for about 10 weeks they develop, as originally shown by Burr & Burr (1929), certain signs of a nutritional deficiency.The signs can be cured or prevented by the inclusion of essential fatty acids (EFA), as linoleic acid, in the diet and the condition is therefore termed EFA deficiency.The weanling male rat has been used extensively in studies concerning EFA deficiency.In this animal the deficiency is characterized by a number of clinical signs such as lower weight gain, scaly skin, partial necrosis of the tail, increased water consumption.B.esides this, the fatty acid pattern in the tissues is different from that in the normal rat.Generally, the concentrations of di-, tetra-, penta-and hexaenoic acids are lower, whereas the concentrations of trienoic and monoenoic acids with 16-18 carbon atoms are higher in deficient than in normal animals (The early changes in the polyenoic fatty acid pattern in the weanling rat fed on an EFA-free diet have not been studied previously.Aaes-Jorgensen & Holman (1958) have demonstrated that the changes in testes polyenes are confined to the first 6 weeks of feeding after which the concentrations remain approximately constant.