不同来源单宁在畜禽养殖中的应用

Application of Different Sources of Tannin in Livestock Farming

单宁是一种天然的酚类化合物,主要表现出抗炎、抗菌、抗氧化、抗病毒等生物活性。然而,不同植物提取的单宁在分子组成和结构上存在显著差异,这导致不同来源单宁在生产养殖中发挥出截然不同的作用。根据其结构,单宁主要分为水解单宁和缩合单宁。缩合单宁常作为反刍家畜饲料添加剂,用于改善瘤胃能量代谢,提高饲料利用率;而水解单宁则大多作为天然的动物促生长剂,广泛应用于猪和家禽养殖中。但在实际应用时,不同浓度的单宁其作用也不尽相同。因此,在畜禽养殖中要充分利用单宁资源,需要综合考虑单宁提取物的来源、单宁的使用剂量及使用对象三方面的因素。作者对不同来源单宁的特点展开综述,诠释了来源于五倍子(Rhus chinensis Mill)、栗木(Castanea sativa Mill)、塔拉(Caesalpinia spinosa)的水解单宁改善不同家畜生长性能的潜在原因,以及来源于坚木(Schinopsis spp.)、柠条(Caragana korshinskii)的缩合单宁改变反刍动物氮代谢途径的可能机制,同时探讨了不同来源单宁的具体应用及其适用剂量,为单宁在畜禽养殖中的实际应用提供理论指导。

Tannin is a kind of natural phenolic compound,which is mainly manifested as anti-inflammatory,antibacterial,antioxidant,antiviral and other biological activities.However,the significant differences in molecular composition and structure of tannin extracted from different plants have led to distinct roles for different sources of tannin in production farming.According to their structures,tannins are mainly divided into hydrolyzed tannin and condensed tannin.It has been shown that condensed tannin is commonly used as feed additives for ruminant livestock to improve rumen energy metabolism and increase feed utilization,while hydrolyzed tannin is mostly used as natural animal growth promoters and more widely used in pig and poultry farming.However,when applied in practice,the use of different concentrations of tannin has diverse effects.Therefore,to make full use of tannin resources in livestock farming,it is necessary to consider the source of tannin extract,the dose of tannin and the target of use.The authors present a review about the characteristics of different sources of tannins,and explain the potential reasons for the improvement of growth performance in different livestock by hydrolyzed tannins from Rhus chinensis Mill,chestnut(Castanea sativa Mill)and tara(Caesalpinia spinosa),and the possible mechanisms for the alteration of nitrogen metabolic pathways in ruminants by condensed tannins from Schinopsis spp.and Caragana korshinskii.Meanwhile,the specific applications of different sources of tannins and their applicable doses are discussed in order to provide theoretical guidance for the practical application of tannins in livestock farming.