2001 年 38 巻 4 号 p. 289-301
To investigate the effects of dietary charcoal powder including wood vinegar compounds (4:1, CWVC) on the intestinal villus morphology, 130-d-old male Single Comb White Leghorn chickens were randomly allotted into 0, 1, 3 and 5% dietary CWVC groups of each 8 bird. Four rations were formulated by addition of each level of CWVC (CP: 2.5%) to commercial layer finisher mash diet (CP: 14.5%, ME: 2,803kcal/kg), and fed ad libitum for 28d. During the feeding experimental period, feed intake and body weight gain were measured. After the end of feeding experiments, 4 birds were randomly selected per each group, and intestinal villus height, epithelial cell area and cell mitosis in each intestinal segment were compared using a light microscope. Besides, the morphological change of villus tip surface was observed using a scanning electron microscope.
Although the feed intake did not differ among each group, the body weight gain tended to be higher in 1 and 3% dietary CWVC groups than that of 0% group, resulting in the feed conversion ratio being insignificantly improved in these groups.
Values of the intestinal villus height, epithelial cell area and cell mitosis were higher in 1% dietary CWVC group but lower in 5% dietary CWVC group than those of another groups in each intestinal segment.
The comparatively smooth surface of the duodenal villus apex in the 0% dietary CWVC duodenum changed to the rough surface with a clear cell outline between each epithelial cell due to the conspicuous cell protuberances after feeding 1% dietary CWVC. However, such conspicuous cell protuberances disappeared and cells having no microvilli and deep cells at the sites of recently exfoliated cells were observed after feeding 3% dietary CWVC, and the latter was much increased after feeding 5% dietary CWVC. Fundamentally, the villus apex surface in the jejunum and ileum revealed an almost similar morphological alteration to that in the duodenum except that cells having no microvilli and deeper cells due to recently exfoliated cells were not seen even in 5% dietary CWVC and that the cell protuberances of 1% dietary CWVC became faint with moving caudally.
The present morphological changes of intestinal villi in chickens fed the dietary CWVC diets demonstrate that the villus function could be activated also in the ileum at 1% level, and that such an activated villus function in all small intestinal segment parts might improve the feed conversion ratio.