Surai Peter F, Kochish Ivan I, Fisinin Vladimir I, Juniper Darren T
Department of Microbiology and Biochemistry, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria.
Moscow State Academy of Veterinary Medicine and Biotechnology Named after K.I. Skryabin, 109472 Moscow, Russia.
Animals (Basel). 2019 Jul 19;9(7):462. doi: 10.3390/ani9070462.
In commercial animals production, productive stress can negatively impact health status and subsequent productive and reproductive performance. A great body of evidence has demonstrated that as a consequence of productive stress, an overproduction of free radicals, disturbance of redox balance/signaling, and oxidative stress were observed. There is a range of antioxidants that can be supplied with animal feed to help build and maintain the antioxidant defense system of the body responsible for prevention of the damaging effects of free radicals and the toxic products of their metabolism. Among feed-derived antioxidants, selenium (Se) was shown to have a special place as an essential part of 25 selenoproteins identified in animals. There is a comprehensive body of research in monogastric species that clearly shows that Se bioavailability within the diet is very much dependent on the form of the element used. Organic Se, in the form of selenomethionine (SeMet), has been reported to be a much more effective Se source when compared with mineral forms such as sodium selenite or selenate. It has been proposed that one of the main advantages of organic Se in pig and poultry nutrition is the non-specific incorporation of SeMet into general body proteins, thus forming an endogenous Se reserve that can be utilized during periods of stress for additional synthesis of selenoproteins. Responses in ruminant species to supplementary Se tend to be much more variable than those reported in monogastric species, and much of this variability may be a consequence of the different fates of Se forms in the rumen following ingestion. It is likely that the reducing conditions found in the rumen are responsible for the markedly lower assimilation of inorganic forms of Se, thus predisposing selenite-fed animals to potential Se inadequacy that may in turn compromise animal health and production. A growing body of evidence demonstrates that organic Se has a number of benefits, particularly in dairy and beef animals; these include improved Se and antioxidant status and better Se transfer via the placenta, colostrum, and milk to the newborn. However, there is a paucity in the data concerning molecular mechanisms of SeMet assimilation, metabolism and selenoprotein synthesis regulation in ruminant animals, and as such, further investigation is required.
在商业动物生产中，生产应激会对健康状况以及随后的生产和繁殖性能产生负面影响。大量证据表明，由于生产应激，会观察到自由基过度产生、氧化还原平衡/信号传导紊乱以及氧化应激。有一系列抗氧化剂可添加到动物饲料中，以帮助建立和维持身体的抗氧化防御系统，该系统负责预防自由基及其代谢有毒产物的破坏作用。在饲料来源的抗氧化剂中，硒（Se）作为动物体内已鉴定出的25种硒蛋白的重要组成部分，具有特殊地位。对单胃动物的大量综合研究清楚地表明，日粮中硒的生物利用率在很大程度上取决于所使用元素的形式。据报道，与亚硒酸钠或硒酸盐等矿物质形式相比，以硒代蛋氨酸（SeMet）形式存在的有机硒是一种更有效的硒源。有人提出，有机硒在猪和家禽营养中的主要优势之一是SeMet可非特异性地掺入全身蛋白质中，从而形成内源性硒储备，在应激期间可用于额外合成硒蛋白。反刍动物对补充硒的反应往往比单胃动物报道的更具变异性，这种变异性很大程度上可能是由于摄入后瘤胃中硒形式的不同命运所致。瘤胃中的还原条件可能是导致无机硒同化明显降低的原因，从而使饲喂亚硒酸盐的动物易出现潜在的硒缺乏，进而可能损害动物健康和生产性能。越来越多的证据表明，有机硒有许多益处，特别是在奶牛和肉牛中；这些益处包括改善硒和抗氧化状态，以及通过胎盘、初乳和乳汁更好地将硒转移给新生动物。然而，关于反刍动物中SeMet同化、代谢和硒蛋白合成调节的分子机制的数据很少，因此需要进一步研究。
