Cassirer E F, Rudolph K M, Fowler P, Coggins V L, Hunter D L, Miller M W
Idaho Department of Fish and Game, Lewiston 83501, USA.
J Wildl Dis. 2001 Jan;37(1):49-57. doi: 10.7589/0090-3558-37.1.49.
We conducted field and laboratory experiments to evaluate whether treating pregnant bighorn ewes with a combination of an experimental Pasteurella trehalosi and Mannheimia haemolytica (formerly P. haemolytica) vaccine and a commercially-available bovine P. multocida and M. haemolytica vaccine would increase lamb survival following a pneumonia epidemic. Three free-ranging bighorn herds affected by pasteurellosis outbreaks between November 1995 and June 1996 were included in the field experiment. Post-epidemic lamb survival was low in all three herds in 1996, with November lamb:ewe ratios of < or = 8:100. In March 1997, thirty-six ewes (12/herd) were captured and radiocollared. Half of the ewes captured in each herd were randomly selected to receive both vaccines; the other half were injected with 0.9% saline solution as controls. Lambs born to radiocollared ewes were observed two or more times per week and were considered to have survived if they were alive in October 1997, about 6 mo after birth. Lamb survival differed among herds (range 22% to 100%), and survival of lambs born to vaccinated ewes was lower (P = 0.08) than survival of lambs born to unvaccinated ewes. Bronchopneumonia (pasteurellosis) was the dominant cause of mortality among lambs examined. We concurrently evaluated vaccine effects on survival of lambs born to seven captive ewes removed from the wild during the 1995-96 epidemic. Antibody titers were high in captive ewes prior to vaccination, and vaccines failed to enhance antibody titers in treated captive ewes. None of the captive-born lambs survived. These data suggest that, using existing technology, vaccinating bighorn ewes following pneumonia epidemics has little chance of increasing neonatal survival and population recovery.
我们进行了野外和实验室实验，以评估用一种实验性的溶血巴斯德氏菌和溶血曼氏杆菌（原溶血巴氏杆菌）联合疫苗以及一种市售的牛多杀性巴氏杆菌和溶血曼氏杆菌疫苗对怀孕大角羊母羊进行治疗，是否会在肺炎流行后提高羔羊的存活率。1995年11月至1996年6月间受巴氏杆菌病疫情影响的三个自由放养的大角羊群被纳入野外实验。1996年，所有三个羊群中疫情后的羔羊存活率都很低，11月的羔羊与母羊比例≤8:100。1997年3月，捕获了36只母羊（每个羊群12只）并佩戴无线电项圈。每个羊群中捕获的母羊有一半被随机选择接受两种疫苗；另一半注射0.9%的盐溶液作为对照。每周对佩戴无线电项圈的母羊所生的羔羊进行两次或更多次观察，如果它们在1997年10月（出生后约6个月）还活着，则被视为存活。不同羊群的羔羊存活率有所不同（范围为22%至100%），接种疫苗的母羊所生羔羊的存活率低于未接种疫苗的母羊所生羔羊的存活率（P = 0.08）。支气管肺炎（巴氏杆菌病）是所检查羔羊死亡的主要原因。我们同时评估了疫苗对1995 - 96年疫情期间从野外捕获的7只圈养母羊所生羔羊存活率的影响。圈养母羊在接种疫苗前抗体滴度很高，疫苗未能提高接受治疗的圈养母羊的抗体滴度。没有一只圈养出生的羔羊存活下来。这些数据表明，使用现有技术，在肺炎流行后给大角羊母羊接种疫苗，提高新生儿存活率和种群恢复的机会很小。
