Several unfavourable food-related effects are attributed to tannins in adolescent animals e. g. Growth depression, reduction of absorption of trace elements and vitamins, Increase in fecal excretion and nitrogen of endogenous origin, inhibition of digestive enzymes, Reduction of Intestinal Absorption of Sugar and Amino Acids, reduction of Immune response increase in catabolism of liver proteins, reduction of pancreatic weight and the activity of cathepsin A and D in the liver
Various methods have been developed to mitigate these negative effects: Addition of binders (tannin binder, polyvinylpyrolidone (PVP)), which have a strong affinity to bind tannins, resulted in significant positive effects. Treatment of Tannin Rich Sorghum (TRS) in wood ash extract improved the growth of poultry by reducing the tannin content. (KYARISIMA et al., 2004). In the ensiling of tannin rich Sorguhm it came to the reduction of tannin content and to increase the feasibility of the crude proteins. (YUNIOR, 2004)
Currently, the use of proline-rich protein has a particular importance as an essential measure against the unfavorable effects of tannin (SKOPEC et al., 2004).
The morphological and immunological changes, which can be caused by tannins on the epithelial cells in the small intestine, has not been studied enough. Several peculiarities of the intestinal epithelial cells make them unique: the Function of the epithelial cells of the small intestine exists not only in digestion and absorption of the Nutrients, but they also serve as antigen-precursor cells (APC): both cells MHC class I (WIMAN et al., 1978; GERD-RÜDIGER et al., 1998; WARREN, 1986; KAISERLIAN et al., 1989; MAYER and SHLIEN, 1987) as well as the MHC class II are expressed (SCOTT et al., 1980, BLAND, 1988) and they serve as antigen-precursor cells for T cells (DANIEL, 2004, KAISERLIAN, 1995). Further, the epithelial cells of the small intestine produced immunoregulatory cytokines that enhance the activity of professional antigen presenting cells (PAPC) (macrophages, dendritic cells and B lymphocytes) (DEEM et al., 1990; CIACCI et al., 1993; HIROSHI et al., 1996). In addition,
The intestinal epithelial cells can increase the activity of CD8 + T cells (BLAND and WARREN, 1986, MAYER and SHLIEN, 1987). The Transport of immunoglobulins IgA and IgG into the lumen of the intestine occurs exclusively by these cells (BRANDTZAEG, 1985): The transmembrane poly-Fc receptor (SC, secretory component) is located on the laminaproprial Surface of these cells, which act as receptors for IgA. (BRANDTZAEG, 1984; BRANDTZAEG and PRYDZ, 1974). Damage to the epithelial cells could therefore be the greatly alter local and systemic immunological parameters; (Activation or inhibition of immune cells). The relationships between villi atrophy and Crypten hyperplasia with increased activity of lamina propria T lymphocytes were experimental proved. (MacDONALD and SPENCER, 1988; LIONETTI et al., 1993; LIONETTI et al., 1995).
The main objective of this work is to study the effects of tannin on the histological Structure of the intestinal wall, as well as on the mucosal immune system in the intestine in poultry