가금티푸스 감염시 Saccharomyces exiguus를 포함한 사료 첨가제가 산란계의 면역 반응에 미치는 영향

This experiment was conducted to investigate the effects of Saccharomyces exiguss supplementation on mortality and immune response with fowl typhoid infection in layer chicks. A total 162 layer chicks of 10 days age were divided into control and different groups. Mortality was checked daily, Body weight was checked at 0, 3 and 6 day post infection(dpi) and blood was collected at 12 dpi for measuring of IgG and IgA by ELISA. There was no mortality in control groups with or without yeast. The mortality between 6~15 dpi was highest (68~84%) in infected group without yeast. However, the mortality reduced (36~44%) significantly in the groups with yeast orally or by both orally and through feed (20~36%). Weight gain was significantly higher in control groups than the infected groups and there was no difference between the infected groups. IgG level increase in both control and infected chicken when given orally than when given both orally and though feeding. In case of IgM though the level increased in control group but it has gradually decreased in the infected group with the use of yeast. The yeast feeding has reduced mortality of chicks from fowl typhoid, though it is not very effective on weight gain and immune response.