Establishment of animal production system with reduced use of antimicrobials by profiling the specific gravity of white blood cell

在综合动物生产中去除或减少抗菌剂的使用是当前安全动物生产政策的一个问题。我们已经开发了一种使用特定重量的白细胞来快速检测仔猪和小牛的表观感染的方法。对仔猪不同时期的血液、粪便和咽拭子中病原体的检测，白细胞比重的变化与评分呈显著负相关。尤其是血细胞在1.072-1.084g/ml范围内变化明显。粒细胞是这一特殊的白细胞组分的主要成分，因此，测量了粒细胞在该组分中的百分比。这种特殊粒细胞的百分比与呼吸道病原体的存在评分之间存在显著的负相关。这证明了本方法快速检测仔猪呼吸道感染的可能性。就小牛而言，受试动物都是在实验农场饲养的，动物数量有限。由于商业生猪生产设施的环境相对清洁，没有观察到检测到白细胞比重与表观感染之间的关系。还需要进一步的研究来证实该方法学在小牛身上的可靠性。

Removal or reduced use of antimicrobials in integrated animal production is a current issue for the safe animal production policy. We have developed a rapid test for in-apparent infection of piglets and calves using specific gravities of white blood cells. When the relationship between change in specific gravity of white blood cells and the scores for presence of pathogens in blood, or swabs of feces and pharynx, tested with piglets at various stages, a significant negative correlation was observed. In particular, change in blood cells of 1.072-1.084g/ml was evident. Granulocytes were the major components of this particular fraction of white blood cells, therefore, percentages of the granulocytes in that fraction was measured. There was a significant negative correlation between percentages of this specific granulocyte and scores for presence of respiratory pathogens. This substantiates the possibility of the present methodology for the rapid test of in-apparent respiratory infection in piglets. In case of calves, tested animals were all raised in experimental farms and numbers of animals were limited. The detection of relationships between the specific gravities of white blood cells and in-apparent infection was not observed due to the relative clean environment to commercial pig production facilities. Further studies are required to confirm the reliability of the methodology in calves.