Ruff M D, Reid W M, Rahn A P, McDougald L R
Poult Sci. 1980 Sep;59(9):2008-13. doi: 10.3382/ps.0592008.
The anticoccidial activity of the ionophore narasin was tested in 3 floor-pen experiments. Narasin was tested at levels of 40, 60, 80, 100, or 120 ppm and compared against feeding ration containing 80, 100, or 121 ppm monensin or no medication. Feeding at all levels of narasin significantly prevented coccidiosis-induced mortality and improved weight gains and feed conversion ratios compared with the same parameters in groups given unmedicated feed. Protection with narasin was equal to or slightly greater than the protection obtained with monensin. The reduction in intestinal lesion scores was greater with narasin medication than with monensin. Analysis of pooled data from these trials indicated that a level between 48 and 96 ppm narasin would provide the optimum, depending on whether maximum weight gain or optimum feed conversion ratio was desired. Testing for coccidial immunity using the immunity challenge technique indicated that, based on the parameters of weight gain and lesion scores, even levels as low as 40 ppm narasin had enough efficacy to significantly reduce the amount of immunity which developed in medicated birds compared with the level of immunity developed in birds receiving unmedicated feed.
在3个地面平养试验中测试了离子载体那拉菌素的抗球虫活性。那拉菌素的测试水平为40、60、80、100或120 ppm，并与含有80、100或121 ppm莫能菌素的日粮或不添加药物的日粮进行比较。与给予未添加药物日粮的组中的相同参数相比，以所有水平的那拉菌素进行饲喂均能显著预防球虫病引起的死亡，并提高体重增加和饲料转化率。那拉菌素的保护效果与莫能菌素相当或略高。那拉菌素用药组的肠道病变评分降低幅度大于莫能菌素组。对这些试验的汇总数据进行分析表明，根据期望的是最大体重增加还是最佳饲料转化率，48至96 ppm之间的那拉菌素水平将提供最佳效果。使用免疫激发技术对球虫免疫力进行测试表明，基于体重增加和病变评分的参数，即使低至40 ppm的那拉菌素水平也具有足够的效力，与接受未添加药物日粮的鸡所产生的免疫力水平相比，能显著降低用药鸡所产生的免疫力。
