Abstract
1. Emulsions of C18unsaturated fatty acids (FA) were infused for 2 h into the intestine of conscious sheep while motility of the reticulum and rumen was recorded.2. Statistically-significant depression of motility was found when 3 or 5 g FA/h were infused. At 1 g/h there were minor disruptions of motility.3. The inhibitory potency was not related to the extent of unsaturation of the FA.4. Receptors mediating the inhibitory effect were postulated to be distal to the iliac flexure of the duodenum, but the possible role of bile and pancreatic juice is discussed in relation to this problem.5. The probability that the effect was hormonally mediated is discussed.