绵羊初乳免疫活性物质动态变化及白利度法评估初乳品质有效性研究  

Dynamic Changes of Immune Active Substances in Sheep Colostrum and Evaluation of Brix Refractometer Method in Predicting Immunoglobulin G Concentration

作　　者：肖汉杰 卢辰思 刘梦雨 王璐[1] 严慧 段春辉[1] 张英杰[1] 纪守坤 刘月琴[1] XIAO Hanjie;LU Chensi;LIU Mengyu;WANG Lu;YAN Hui;DUAN Chunhui;ZHANG Yingjie;JI Shoukun;LIU Yueqin(College of Animal Science and Technology,Hebei Agricultural University,Baoding,Hebei 071000,China)

机构地区：[1]河北农业大学动物科技学院,河北保定071000

出　　处：《家畜生态学报》2024年第9期39-45,共7页Journal of Domestic Animal Ecology

基　　金：河北省自然科学基金青年基金项目(C2020204181);河北省重点研发项目(19226627D);国家肉羊产业技术体系(CARS-39);河北省省属高等学校基本科研业务费研究项目(KY202016)。

摘　　要：本试验旨在研究母羊初乳中免疫球蛋白(Ig)和乳铁蛋白(LF)的含量随时间变化的规律,并验证白利度(Brix)折光仪在生产实践中评定绵羊初乳品质的可行性。选用10只健康湖羊,采集母羊分娩后0、6、12、24、36和72 h的初乳,利用单向免疫扩散法(RID)测定IgG含量和酶联免疫吸附测定法(ELISA)测定IgA、IgM和LF的含量,从而探索其72 h内的时序变化,同时利用手持折光仪和数显折光仪(Brix法)检测初乳IgG含量,对Brix法评估初乳品质的有效性进行评估。结果显示:初乳中IgG、IgA和LF含量随泌乳时间延长呈线性下降(P<0.05);IgM含量在72 h内相对稳定。0~24 h绵羊初乳样品的数显折光仪和手持折光仪读数均与RID测定的IgG含量高度相关(r>0.66);对于0~24 h初乳样品,数显折光仪读数预测初乳IgG含量公式为:y=204.92x-4.3266(R^(2)=0.70,P<0.05),预测偏差为0.01 mg/mL,预测误差为35.9%;手持折光仪读数预测IgG含量公式为:y=291.52x-18.75(R^(2)=0.71,P<0.05),预测偏差为0.00 mg/mL,预测误差为34.3%。采用IgG含量高于50 mg/mL为高品质初乳的判断标准,手持和数显折光仪读数应分别高于23.6%和26.5%。综上所述,初乳中IgG、IgA和LF含量随母羊产后时间延长呈线性下降,IgM含量在72 h内相对稳定;Brix法测定绵羊产后0~24 h的高品质初乳,手持折光仪Brix%>23.6%,数显折光仪Brix%>26.5%。This experiment was conducted to study the variation of immunoglobulin(Ig)and lactoferrin(LF)content in ewe colostrum with time,and the evaluation on the accuracy of the Brix refractometer method to estimate immunoglobulin G concentration.Ten healthy Hu sheep were selected to collect colostrum at 0,6,12,24,36 and 72 hours after delivery,the IgG content in colostrum was determined by radial immunodiffusion(RID)method,and the IgA,IgM and LF content was determined by enzyme-linked immunosorbent assay(ELISA)method,to explore the temporal change of immunoglobulin(Ig)and lactoferrin(LF)content in colostrum within 72 h after delivery.The colostrum was also scanned by hand-held refractometer and digital refractometer(Brix method)for evaluation of the accuracy of the Brix refractometer method in estimating immunoglobulin G concentration.The results showed the contents of IgG,IgA,and LF in colostrum linearly decreased with the lactation time(P<0.05),while IgM content was stable.For 0~24 h colostrum samples,the results from the digital refractometer,and hand-held refractometer were highly correlated with that from RID(r>0.66),and the formula for predicting IgG content in colostrum by digital refractometer was y=204.92x-4.3266(R^(2)=0.70,P<0.05),with MB being 0.01 mg/mL,and RMSPE 35.9%;the formula for predicting IgG content by handheld refractometer was y=291.52x-18.75(R^(2)=0.71,P<0.05),with MB being 0.00 mg/mL and RMSPE 34.3%.Using IgG content higher than 50 mg/mL as the threshold of high-quality colostrum,hand-held refractometer reading should be higher than 23.6%,and digital refractometer reading should be higher than 26.5%.In conclusion,the IgG,IgA,and LF contents in colostrum linearly decrease with the extension of lactation time,and the content of IgM is stable within 72 h.Brix method can be used to determine the quality colostrum of sheep at 0~24 hours postpartum,with Brix%>23.6% by hand-held refractometer and 26.5% by digital refractometer being considered high-quality colostrum.

关 键 词：初乳 Brix折光仪 免疫球蛋白 乳铁蛋白 

分 类 号：S826.94[农业科学—畜牧学]