Potential and challenges of tannins as an alternative to in-feed antibiotics for farm animal production

Huang, Qianqian; Liu, Xiuli; Zhao, Guoqi; Hu, Tianming; Wang, Yuxi

Grape pomace, which includes skins, pulp and contain significant amount of CT and other simple phenolic compounds, is the byproduct of grape processing. Several studies evaluating the effects of grape pomace on swine and poultry performance indicated that addition of such tannin-rich product up to 10% of the diet had no effect on growth performance of broiler chicken, but enhanced anti-oxidant status and increased intestinal populations of beneficial bacteria (Brenes et al., 2008; Viveros et al., 2011; Chamorro et al., 2015) . Yan and Kim (2011) showed that supplementation of a Saccharomyces boulardii fermented grape pomace to pig diets at the level of 0.3% improved growth performance, nutrients digestibility and altered the fatty acid pattern in the subcutaneous fat as well as some attributes of pork meat. The grape pomace was also found to improve antioxidant activity of pork and reduced the gastrointestinal absorption of mycotoxins in swine. These effects of grape pomace, however, may not be exclusively attributed to the CT because other phenolic compounds also are present in the product.