RELATIONSHIP BETWEEN GROWTH OF ANIMALS AND POLYUNSATURATED FATTY ACID

Abstract

1) When groups of rats of various body weights were fed on a diet deficient in the polyunsaturated fatty acid, all the animals in Group I (average body weight of 52g), Group II (average body weight of 60g), Group III (average body weight of 65g), and Group IV (average body weight of 73g) died during 56, 72, 79, and 85 days, respectively. Whereas in Group V, the control (average body weight of 53g), all the animals were still alive after 86 days of feeding, this being ascribed to the supplementation to the diet with linseed oil containing the polyunsaturated fatty acid. The data also indicate that the younger the animals the less resistant they are to the polyunsaturated fatty acid deficiency.
2) There was a marked difference in the linoleic acid content of the unsaturated fatty acid in the fat of the lipid constituents of muscles between the mature (5.5%) and the immature rats (29.2%). The linoleic acid contents in the phosphatide was 33.1% in the mature and 42.3% in the immature rats. The amounts of linolenic and arachidonic acids were slightly more in the immature than in the mature rats.
3) The above results indicate that the younger animals die in the earlier period of feeding the polyunsaturated fatty acid deficient diet, because they require more of the polyunsaturated fatty acid to construct their cells.
4) According to Ara's data on the lipid constituents of animal cells(3), the iodine number of the fatty acid of fat is 100 and that of phosphatide is 115. When the iodine number of fatty acid is more than 100, it cannot be attained by oleic acid alone but the polyunsaturated fatty acid must be participated. The present study revealed that the younger the animals the more of the poly-unsaturated fatty acid they require.