Percentages of milk fat, lactose, solids-not-fat
and SCC were not affected by treatments except for an increase in milk protein content in oil supplemented
groups. The fatty acid (FA) profile of milk was altered by fat supplementation. Feeding plant oils reduced the
proportion of both short-chain (C4:0 to C12:0) and medium-chain (C14:0 to C16:1) fatty acids, and increased
the proportion of long-chain (≥ C18:0) fatty acids in milk fat. The inclusion of vegetable oils increased the concentration
of cis-9, trans-11 CLA. The cis-9, trans-11 CLA content in milk fat was higher from RSO to PNO and
SFO was higher than the control. The TVA concentration was higher in the SFO diet, followed by PNO, RSO,
and control diets. The results of this study indicated that linoleic acid was more effective in enhancing contents
of TVA and CLA in milk fat than oleic acid. No significant effects of week and treatment by week interaction
were found out in this study. Overall, feeding plant oils increased monounsaturated and polyunsaturated fatty
acids and decreased saturated fatty acids in milk fat. In conclusion, dietary supplementation of RSO increases
milk yield the most, while SFO enhances the cis-9, trans-11 CLA content in milk fat more effectively.