The effects of different levels of Whole Cottonseed (WCS) on feedlot performance and on the
morphology of small intestine, in 20 Chaal male lambs were studied for a duration of 90 days. A
completely randomized design of four diets containing 0, 4, 8 and 16 percent WCS was employed.
Number and dimensions of different types of villi and depths of crypt gland were evaluated. The
metabolisable energy and protein contents of rations were chosen as equal. Different levels of WCS in
diet exerted no significant effect on body weight gain and feed conversion ratio, but the sheep
consumed diets containing 4 % WCS more than they did the other diets (p<0.01).. The effect of diet
was significant only on the number of leaf shape villi (p<0.01). The difference among the numbers of
all types of villi in different parts of intestine samplings (duodenum, jejunum, ileum), was also
significant. Villus dimensions and depth of crypt gland were affected by diet and sampling sites. It was
finally shown that, WCS can increase villus heigh: crypt depth ratio and can be included in the
fattening ration of a male lamb’s diet to an extent of 16 percent.