Composition of Long-chain Fatty Acids in The Rumen of Cows

The composition of long-chain fatty acids in the rumen was investigated in cows reared on different types of feed in open fields. Feed consumption caused a decrease in stearic acid (C18), a saturated fatty acid, and an increase in oleic acid (C18=1) and linoleic acid (C18=2), unsaturated fatty acids. The saturated fatty acid concentration was predominantly increased at three hours after feeding, and continued until the next feeding. Durig the fasting period, there were a marked decrease in C18 and an increase in C18=1 and C18=2. An increase in C18=2 was observed in the cattle groups with frequent onsets of digestive tract disorders reared on high and lowenergy feeds. C18=2 was not increased in the group fed a balanced feed or in the group grazed on green grass alone. A marked increase in C18=2 was found in some of the cattle with displacement of the abomasum.