Boyd J W, Boyd A J
Virginia-Maryland Regional College of Veterinary Medicine, Department of Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
Res Vet Sci. 1987 Nov;43(3):291-6.
The transfer of immunoglobulin (Ig) isotypes (IgG1, IgG2, IgM), gamma-glutamyl transpeptidase (gamma-GT) and added D-xylose from colostrum to serum was investigated in newborn Holstein bull calves. Significant differences were observed in the time courses of the serum concentrations of these colostrum constituents following absorption from pooled colostrum. A computer model was devised to simulate the process of absorption of Ig isotypes, gamma-GT and D-xylose from colostrum in the newborn calf. A Fortran program was used to generate plots of the time course of the concentration of colostrum constituents in serum and other body fluids following a single feed of colostrum. These plots show how the changes in serum concentration of absorbed Ig isotypes, gamma-GT and D-xylose are affected by different rates of intestinal absorption, redistribution in body fluids and removal from plasma. A critical examination of data from the computer model and from the calf feeding experiments supports the view that the absorption of IgG1, IgG2 and IgM is not selective in the calf. The data were compared with earlier studies of the efficiency of the colostral transfer of Ig to the calf. In the present study the transfer efficiencies of IgG1, IgG2, IgM, gamma-GT and D-xylose were 46 per cent, 49 per cent, 47 per cent, 18 per cent and 21 per cent, respectively.
对新生荷斯坦公牛犊从初乳到血清中免疫球蛋白（Ig）同种型（IgG1、IgG2、IgM）、γ-谷氨酰转肽酶（γ-GT）以及添加的D-木糖的转移情况进行了研究。从混合初乳吸收后，这些初乳成分在血清中的浓度随时间变化过程存在显著差异。设计了一个计算机模型来模拟新生犊牛初乳中Ig同种型、γ-GT和D-木糖的吸收过程。使用Fortran程序生成单次投喂初乳后血清及其他体液中初乳成分浓度随时间变化的曲线图。这些曲线图展示了吸收的Ig同种型、γ-GT和D-木糖在血清中的浓度变化是如何受到不同肠道吸收速率、体液再分布以及从血浆中清除的影响。对计算机模型和犊牛饲养实验数据的严格审查支持了这样一种观点，即犊牛对IgG1、IgG2和IgM的吸收没有选择性。将这些数据与早期关于初乳中Ig向犊牛转移效率的研究进行了比较。在本研究中，IgG1、IgG2、IgM、γ-GT和D-木糖的转移效率分别为46%、49%、47%、18%和21%。
