Nutritional Studies with the Guinea Pig

Young male guinea pigs were reared for 6 to 14 weeks with purified diets containing varying levels of linoleic acid as corn oil, safflower oil, or methyl linoleate. A dietary level of about 1% of calories as linoleic acid was necessary for normal growth and skin condition. The fatty acid composition of erythrocytes from animals fed safflower oil was determined and the ratios of 5,8,11-eicosatrienoic-to-arachidonic (20:3/20:4) or oleic-to-linoleic (18:1/18:2) acids compared with the performance of the animals with respect to growth and dermal symptoms. One per cent of calories as linoleic acid gave a 20:3/20:4 ratio of 0.13 to 0.17, and a 18:1/18:2 ratio of 1.41 to 1.14. Homogenates of liver from linoleic acid-deficient guinea pigs had an elevated rate of oxidation of citrate and α-ketoglutarate.