摘要
Ionophores are used commercially throughout the world in the beef and poultry industries. Production efficiency of cattle is increased through alteration of rumen fermentation and control of protozoa that cause coccidiosis. Ionophores act by interrupting transmembrane movement and intracellular equilibrium of ions in certain classes of bacteria and protozoa that inhabit the gastrointestinal tract. The actions of ionophores provide a competitive advantage for certain microbes at the expense of others. In general, the metabolism of the selected microorganisms favors the host animal. Energy metabolism is enhanced through increased production of propionate among ruminal fatty acids with a concomitant reduction in methane. Ruminal degradation of peptides and amino acids is reduced, thereby increasing the flow of protein of dietary origin to the small intestine. Total flow of protein to the lower tract is often increased with ionophore feeding. Risk of digestive disorders such as bloat and acidosis that result from abnormal rumen fermentation is reduced, as are certain conditions caused by toxic products of fermentation, e.g., 3-methyl indole. Dry matter and nitrogen digestibilities are increased with ionophores, thereby providing environmental benefits. Monensin and lasalocid have been the most studied in research demonstrating benefits to the dairy cow. Ionophores enhance the glucose status of dairy cows through increased production of propionate. Many of the demonstrated benefits of ionophores are associated with enhancement of the energy status of the cow in the transition period and during early lactation. The benefits include less mobilization of body fat as evidenced by reduced blood nonesterified fatty acids and ketones and increased glucose. Animal manifestations include lower incidence of ketosis and displaced abomasum, reduced loss of body condition, increased milk production, and improved milk production efficiency.
摘要译文
通过改变瘤胃发酵和控制引起球虫病的原生动物来提高牛的生产效率。离子载体通过中断某些类别的细菌和居住在胃肠道的原生动物中的离子的跨膜运动和细胞内平衡来起作用。离子载体的作用为某些微生物提供了竞争优势而牺牲了其他微生物。通常，所选微生物的代谢有利于宿主动物。通过增加瘤胃脂肪酸中丙酸盐的产生来增强能量代谢，同时伴随甲烷的减少。肽和氨基酸的瘤胃降解减少，从而增加了饮食来源的蛋白质流向小肠。通过离子载体喂养，蛋白质到下部道的总流量通常增加。由于瘤胃发酵异常导致的消化紊乱（例如膨胀和酸中毒）的风险降低，发酵的有毒产物引起的某些病症，例如，3-甲基吲哚。用离子载体增加干物质和氮的消化率，从而提供环境效益。莫能菌素和拉沙里菌素在研究中研究最多，证明了对奶牛的益处。离子载体通过增加丙酸盐的产量来增强奶牛的葡萄糖状态。离子载体的许多已证明的益处与过渡期和泌乳早期期间母牛的能量状态的增强有关。其益处包括减少体内脂肪的动员，这可以通过减少血液非酯化脂肪酸和酮和增加的葡萄糖来证明。动物表现包括较低的酮症发生率和移位的皱胃，减少的身体状况损失，增加的产奶量和提高的产奶效率。
R.K.McGuffey;L.F.Richardson;J.I.D.Wilkinson;. Ionophores for Dairy Cattle: Current Status and Future Outlook[J]. Journal of Dairy Science, 2001,84(Sup): E194-E203