Tannins in poultry production

Tannins are a complex group of polyphenolic compounds found in a wide range of plant species that can precipitate proteins. These molecules are secondary metabolites of plants, which are found seeds, bark, wood leaves, and fruit skins and play important role in many natural ecological processes, such as herbivore defense, litter decomposition, nutrient cycling, nitrogen sequestration, and microbial modulation. The physical and chemical properties of tannins are particular of each plant species, the harvest region, and the extraction process. From chemical classification, plant tannins are grouped in hydrolyzable tannins and condensed tannins. Harmful nutritional consequences have been attributed to tannins because they can precipitate proteins, inhibit digestive enzymes, and decrease the utilization of vitamins and minerals. However, it highly depends on tannin concentration. The use of tannins in poultry production sector show favorable results, but the mechanism by which tannins promote growth and health in the monogastric animals are not clear. In general, tannins show variable antimicrobial, antiparasitic, antiviral, antioxidant, anti-inflammatory activities, and intestinal and environmental microbiota modulation. The data produced in the last few years about tannins and animal production provide an arena for discussion of each one of these actions potentially providing positive, negative, or neutral effects on productive efficiency, nutrition, gut health, and disease challenge. The ultimate improvement in performance arises because the sum of differences between these complex effects of tannins on nutrient digestion, microbial communities, and host response.

Key Words: tannins, poultry, health, production.

Presented at the 10th Symposium on Gut Health in Production of Food Animals 2022, St. Louis, USA.