Effect of Tannins on Poultry Nutrition


Tannins are widely known plant ingredients that are found in some animal and plant foods. (LIENER, 1980; BRESSANI, 1983; GUPTA, 1987) 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 (MARZO et al., 2002).

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. 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.

The morphological and immunological changes, which can be caused by tannins on the epithelial cells in the small intestine, has not been studied enough. 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.