The experimental knowledge on efficacy,possible modes of action and aspects of application of Chinese herbs as feed additives for animal production are reviewed in this article.Chinese herbs commonly contain protein,carbohydrate,fat,vitamins,andmineral which are necessary nutrients to the growth of animal.Polysaccharide,organic acid,alkaloids,and essential oils involved in Chinese herbs can improve the immune function of livestock.Currently,numerous studies have demonstrated anti-oxidative and anti-microbial efficacy and the assumption that Chinese herbs may improve the flavor of meat,which has been confirmed by some observations,but the mode of this action is still unclear.Moreover,several observations support the hypothesis that herbal feed additives may favorably affect gut functions （e.g.,enzyme activity,microbial eubiosis） in vitro.Such effects may explain a considerable number of practical studies with livestock reporting improved production performance after providing herbal feed additives.In summary,available evidence indicates that herbal feed additives may have the potential to add to the set of non-antibiotic growth promoters for use in livestock,such as organic acids and probiotics.However,a systematic approach toward the efficacy,mode of action and safety of herbal compounds used as feed additives for animal production seems to be required in the future.
