摘要
从山东省某规模化猪场随机选择5头健康母猪,在其分娩前35 d免疫1头份猪繁殖与呼吸综合征(PRRS)减毒活疫苗。从5头母猪分娩的仔猪中随机选择30头,于0,4,7,10,16,21,28,35日龄时采集各仔猪前腔静脉血分离血清,测定PRRS抗体水平及抗体阳性率,以探究仔猪PRRS抗体消长情况。为探究仔猪接种PRRS疫苗的最佳首免日龄,选择175头健康仔猪,随机分为7组,每组25头,分别于0,7,14,21,28,35日龄时免疫PRRS减毒活疫苗,并于免疫后7,14,21,28,35 d时采集血清测定其PRRS抗体水平及抗体阳性率。结果显示,仔猪吮吸初乳后逐渐获得高水平的母源抗体,于4日龄时达到峰值且阳性率高达100%;7日龄及10日龄时,仔猪体内PRRS抗体仍处在峰值附近,且阳性率为100%;此后,PRRS抗体及阳性率逐渐降低,在28日龄时接近阴性,在35日龄时大部分转为阴性。不同日龄进行首免的各组仔猪中,0日龄免疫组在免疫后7 d即可产生高水平PRRS抗体,且阳性率达75%,之后PRRS抗体逐渐增高,且阳性率逐渐增至96%;4日龄免疫组除在免疫后7 d处于临界值(S/P=3.9)外,其余时间点PRRS抗体均呈阳性,但阳性率为70%~83%;7日龄免疫组与4日龄免疫组相似,除免疫后7 d处于较低值(S/P=0.26)外,其余各时间点PRRSV抗体均呈阳性;而14,21,28,35日龄免疫组仔猪在免疫后14 d之前PRRS抗体均为阴性,血清转化出现在14 d或21 d后,但阳性率较高。综上,妊娠母猪产前35 d免疫PRRS减毒活疫苗所产仔猪体内PRRS母源抗体均值在4日龄时达峰值,28日龄时衰减至接近阴性,而35日龄时大部分转为阴性;仔猪分娩当天(吮吸初乳前)或分娩后4~7 d进行PRRS减毒活疫苗免疫均能使仔猪迅速产生较高水平阳性抗体,且具有较长的免疫持续时间和PRRS抗体阳性率,是较为合理的免疫方案。
This study intends to explore the fluctuant rule of antibodies of PRRS in newborn piglets delivered from gestating sows vaccinated with porcine reproductive and respiratory syndrome(PRRS)live attenuated vaccine,and explore the best date of initial immunization for the piglet delivered from sows inoculated with PRRS vaccine.Five healthy pregnant sows were randomly selected from a large-scale breeding farm in Shandong province and immunized with a PRRS live attenuated vaccine 35 d before delivery.Thirty piglets were randomly selected from the piglets delivered by five sows.Serum was collected at 0,4,7,10,16,21,28,and 35 days of age to determine the PRRS antibody level and antibody positive rate of each piglet.Then 175 healthy piglets were selected and were randomly divided into 7 groups with 25 pigs in each group,they were immunized with PRRS vaccines at 0,7,14,21,28,and 35 days of age.Serum was collected at 7,14,21,28,and 35 d post immunization to determine the PRRS antibody level and antibody positive rate,so as to explore the best date of initial immunization of the piglets inoculated with PRRS vaccine.The results showed that the piglets gradually obtained high levels of maternal antibodies after sucking the colostrum,reaching apeak at 4 days of age with 100%positivity;at 7 and 10 days of age,the PRRS maternal antibodies in the piglets were still near the peak,and the positive rate was 96%.After that,the PRRS antibody level and positive rate gradually decreased,approaching negative at 28 days of age,and most of them turned negative at 35 days of age.Among the groups of piglets vaccinated at different ages,the 0-day-old immunized group produced high levels of PRRS antibodies on the 7 th day after immunization,and the positive rate reached 75%;after that,the PRRS antibodies gradually increased,and the positive rate gradually increased to 100%.In the 4-day-old immunization group,except for the critical value(S/P=3.9)on the 7 th day after immunization,PRRS antibodies were positive at other time points,and the positive rate was 70%-83%.The 7-day-old immunization group was similar to the 4-day-old immunization group,and the PRRSV antibody was positive at all time except for the 7 days after immunization(S/P=0.26).In addition,piglets in the14-day-old,21-day-old,28-day-old and 35-day-old immunization groups were all negative for PRRS antibodies before 14 dafter immunization,and seroconversion occurred after 14 dor 21 d,but the positive rate of PRRS antibodies was higher.In conclusion,the average value of PRRS maternal antibody in piglets reached a peak at 4 days of age,declined to nearly negative at 28 days of age,and turned negative at 35 days of age;therefore,immunization of piglets with the PRRS live attenuated vaccine on the day of delivery(before colostrum sucking)or from 4 to 7 dafter delivery could quickly produce high levels of positive antibodies,with a longer duration and positive rate,which is relatively reasonable immunization program.
作者
高胜
李洋
马志倩
李志伟
徐乐乐
焦点
冯英桐
杜兴乾
肖书奇
GAO Sheng;LI Yang;MA Zhiqian;LI Zhiwei;XU Lele;JIAO Dian;FENG Yingtong;DU Xingqian;XIAO Shuqi(College of Veterinary Medicine,Northwest Agricultural and Forestry University,Yangling,Shannxi 712100)
出处
《中国兽医学报》
CAS
CSCD
北大核心
2021年第10期1909-1914,共6页
Chinese Journal of Veterinary Science
基金
国家重点研发计划资助项目(No.2017YFD0500605)
陕西省杰出青年科学基金资助项目(No.2021JC-18)
陕西高校青年创新团队资助项目
西北农林科技大学试验示范站科技创新与成果转化资助项目(No.TGZX2020-24)。
关键词
猪繁殖与呼吸综合征疫苗
PRRS抗体
消长规律
首免日龄
porcine reproductive and respiratory syndrome vaccine
PRRS antibody
fluctuant rule of antibodies
the date of initial immunization
