Sklan, D., Fac. Agric., Hebrew Univ. Jerusalem, Rehovot, Israel
Budowski, P., Fac. Agric., Hebrew Univ. Jerusalem, Rehovot, Israel
Ascarelli, I., Fac. Agric., Hebrew Univ. Jerusalem, Rehovot, Israel
Hurwitz, S., Fac. Agric., Hebrew Univ. Jerusalem, Rehovot, Israel

Lipid absorption was measured in 19 day old chicks after feeding diets containing raw or heated soybean meals for 4 days. 91Y served as an unabsorbed reference substance. There was considerable secretion of total fatty acids, lipid phosphorus, cholesterol and bile acids into the duodenum, accompanied by rapid absorption of all components between the duodenum and upper jejunum. Absorption of residual lipids and bile acids decreased steadily in the lower jejunum and ileum. Raw soybean meal caused greatly enhanced secretion of total fatty acids, lipid phosphorus, cholesterol and bile acids into the duodenum as compared to chicks fed heated soybean meal. There was also a markedly increased absorption of lipids and bile acids between the duodenum and upper jejunum, but a reduced rate of disappearance of the residual amounts of these compounds in the ileum and colon. The overall net absorption of fatty acids was slightly reduced by raw soybean meal, but quantitatively this effect was very small compared to the increased secretion and absorption.