Effect of feeding different fat supplements on the fatty acid composition of goat milk

The effect of feeding dietary fat supplements on the fatty acid composition of goat milk was examined. Inclusion of canola and soybean (80/20; w/w) oilseed supplement protected from ruminal hydrogenation, significantly increased the proportion of C18:1 (oleic acid), C18,2 (linoleic acid) and decreased the proportion of C16:0 (palmitic acid) and C14:0 (myristic acid), while there was a small increase in C18:0 (stearic acid). Feeding protected cotton seed significantly increased C18:2 and C18:0, but there was a reduction in C18:1 while the C16:0 was unchanged. When combinations of protected cotton seed and protected-canola soybean (80/20; w/w) were fed, a level of 20-25% incorporation of protected cotton seed was sufficient to inhibit the desaturase enzyme, with an increase in the proportion of C18:0. In contrast, feeding calcium salts of fatty acids, a predominantly saturated fatty acid supplement, increased C16:0 and reduced C10:0 (decanoic acid) and C14:0. Feeding fat supplements of different fatty acid compositions and varying levels of inertness in the rumen will enable significant manipulation of the fatty acid composition of milk fat. (C) 1997 Elsevier Science B.V.