Enlargement of the caecum in the rat in iron deficiency

It is known that the composition of a rat's diet may affect the size of its caecum.Wierda (1942) observed that the length of the caecum was increased in animals fed on a diet supplemented with 10-30% agar, compared to animals on similar but unsupplemented diets.The caecums were larger in rats fed on a diet supplemented with dextrinized maize starch than in animals fed on a similar diet supplemented with sucrose (Johansson & Sarles, 1949).Fischer (1957) found an increase in the absolute and relative caecal weights in rats fed on diets containing 25 % lactose, agar or raw potato starch or 10% arabinose, but not with 25 Yo wood cellulose, compared with control animals given maize starch as their only carbohydrate.Moinuddin & Lee (1959) made similar observations.In the course of work with a semi-synthetic diet used for the experimental production of iron deficiency in rats, caecal enlargement was observed (Taylor & Witts, 1958; Valberg, Taylor, Witts & Richards, 1961).We report here an investigation of the relationship of diet, and of Fe deficiency, with the size of the rat's caecum.