The Role of Bile and Pancreatic Juice in the Absorption of Fat in Ewes and Lambs.

The role of the lymphatic system in the absorption of fat in sheep and lambs was investigated by Heath & Morris (1962) and their experiments showed that a considerable proportion of the dietary fat is absorbed into the intestinal lymph and carried to the blood by way of the thoracic duct. In young lambs, the pattern of fat absorption resembles that in cats, rats and rabbits. When a fat meal is given into the rumen of an adult sheep, fat absorption is slow and occurs over a period of days; if, however, the fat meal is given into the abomasum or duodenum, the pattern of absorption is much more rapid. In sheep under normal conditions, the absorption of fat appears to be a continuous process, and there is evidence that long-chain fatty acids of the dietary lipids are being continuously modified by ruminal micro-organisms. In this regard, it has been shown that the ruminal micro-organisms are capable of hydrolysing long-chain triglycerides (Garton, Hobson & Lough, 1958), and hydrogenating unsaturated fatty acids (Reiser, 1951; Garton et al. 1958). These preliminary changes which take place in the rumen may be very important in determining the subsequent absorption of the dietary lipids and in modifying the part played by bile and pancreatic juice in the small intestine. The experiments described in this paper were carried out in vivo to study the effects of continued deprivation of bile and pancreatic juice on the content of lipids in the intestinal lymph and on the lymphatic absorption of 14C-labelled fatty acids from the gut of adult sheep and young lambs. Experiments were also done to measure in vitro the lipolytic activity of sheep pancreatic juice in the presence and absence of bile and of calcium ions. 7954).