Effects of Semi-purified Pellet Diet on the Chicken Intestinal Villus Histology

Abstract

To establish the basic histological data on intestinal villi in chickens fed a semi-purified pellet diet, birds were divided into the following groups : intact control (IC), 3-d fasting (F), ad libitum refeeding of a formula mash diet (AFM), or force-feeding of a formula pellet diet (FFP) or a semi-purified pellet diet (FSP) for one day after 3-d fasting. The intestinal histological recovery in these groups was compared with light (LM) and scanning electron microscopy (SEM). The body weight recovery was similar in AFM and FFP, but they tended to be faster than that of FSP. In LM observations, the decreased values of villus height, cell area, cell mitosis, and villus area in F tended to recover to the IC level in AFM and FFP and but did not recover in FSP. All parameters of AFM and FFP were almost the same. In SEM observations, the dome-shaped cells, cell outlines, and cell protuberances seen in IC became faint in F, and the luminal surface area of the cells became small (P<0.05). After refeeding, the dome-shaped cells and the clear cell outline reappeared in AFM and FFP, and such a morphological recovery was clearer in FFP than AFM. The luminal surface area of the cells tended to increase in AFM and increased in FFP (P<0.05). In addition, cell clusters were frequently observed in FSP. The present histological observations after refeeding suggest that the formula diet can induce hypertrophic intestinal histological alterations at the villus and cell levels. However, although the semi-purified diet does not bring about the histological activation of the villi, it is quicker than the formula diet to activate the cell function. Therefore, it seems that the formula diet produces intestinal histological alterations related to intestinal function at LM and SEM levels, but such a relationship is limited to the SEM level in the semi-purified diet. This demonstrates that nutritional and physiological data from the semi-purified diet cannot always be applied to feeding with a formula diet.

Keywords

• semi-purified diet
• pellet
• intestinal villi
• absorptive epithelial cells
• histological change