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 compos ition of goat milk was examined. Inclusion of canola and soybean (80/2 0; w/w) oilseed supplement protected from ruminal hydrogenation, signi ficantly increased the proportion of C18:1 (oleic acid), C18,2 (linole ic 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 an d C18:0, but there was a reduction in C18:1 while the C16:0 was unchan ged. When combinations of protected cotton seed and protected-canola s oybean (80/20; w/w) were fed, a level of 20-25% incorporation of prote cted 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 level s of inertness in the rumen will enable significant manipulation of th e fatty acid composition of milk fat. (C) 1997 Elsevier Science B.V.