Sharaf M M, Nestor K E, Saif Y M, Sacco R E, Havenstein G B
Department of Poultry Science, Ohio State University, Wooster 44691.
Poult Sci. 1988 Dec;67(12):1807-9. doi: 10.3382/ps.0671807.
Two lines of turkeys were challenged with Pasteurella multocida during three trials. The two lines were 1) a randombred control line (RBC1), and 2) a subline (E) of Line RBC1 selected for increased egg production. Each trial differed as to the age at which poults were challenged. In Trial 1, unvaccinated birds were subcutaneously inoculated with P. multocida at 6 wk of age. In Trial 2, poults vaccinated (on the back of the neck) at 7 and 9 wk of age with .5 mL of P. multocida bacterin and unvaccinated poults were challenged at 11 wk of age. Trial 3 was similar to Trial 2, except that poults were vaccinated at 8 and 10 wk of age and challenged at 12 wk of age. Line E had significantly (P less than .05) higher mortality than Line RBC1 (66.7 vs. 31.8%) in Trial 1. In Trials 2 and 3, unvaccinated birds of Line E had higher mortality than unvaccinated birds of Line RBC1; however, differences between lines were not significant in either trial. Significantly lower levels of mortality were observed for vaccinated poults than for unvaccinated poults in the second and third trials, where birds were vaccinated and challenged at older ages.
在三项试验中，用多杀性巴氏杆菌对两系火鸡进行攻毒。这两系分别是：1）一个随机交配对照系（RBC1），以及2）从RBC1系中选出的用于提高产蛋量的一个亚系（E）。每项试验在雏火鸡接受攻毒的年龄上有所不同。在试验1中，未接种疫苗的雏鸡在6周龄时皮下接种多杀性巴氏杆菌。在试验2中，7周龄和9周龄时在雏鸡颈部后方接种0.5毫升多杀性巴氏杆菌菌苗，未接种疫苗的雏鸡在11周龄时接受攻毒。试验3与试验2相似，不同之处在于雏鸡在8周龄和10周龄时接种疫苗，在12周龄时接受攻毒。在试验1中，E系的死亡率显著高于RBC1系（66.7%对31.8%，P小于0.05）。在试验2和试验3中，E系未接种疫苗的雏鸡死亡率高于RBC1系未接种疫苗的雏鸡；然而，在这两项试验中两系之间的差异均不显著。在第二项和第三项试验中，即雏鸡在较大年龄接种疫苗并接受攻毒的试验中，观察到接种疫苗的雏鸡死亡率显著低于未接种疫苗的雏鸡。
