Department of Pathobiology, Ontario Veterinary College, University of Guelph, ON, Canada N1G 2W1.
J Dairy Sci. 2011 Feb;94(2):981-91. doi: 10.3168/jds.2010-3329.
Selection for production traits with little or no emphasis on health traits has led to an increase in the incidence of disease in Canadian dairy herds. We describe here a patented protocol for estimating the breeding value for immune responsiveness in heifers that combines measures of both cell-mediated (CM) and antibody-mediated (AM) immune responses (IR). The ability of putative type 1 and type 2 antigens used to induce CMIR and AMIR, respectively, was assessed in replacement Holstein heifers, and the effects of age and pregnancy on type 1 and type 2 IR bias were estimated. Results demonstrated that the type 1 and type 2 antigens induced polarized type 1 and type 2 responses in heifers regardless of age and pregnancy status, and can therefore be used to identify animals with superior overall immune responsiveness. However, age and pregnancy status had significant effects on adaptive IR profiles, highlighting the need for appropriate statistical modeling of such effects when ranking animals on their ability to mount CM and AMIR. Responses became increasingly type 1 biased as heifers approached 12 mo of age, from which point, responses then became increasingly type 2 biased with age and length of gestation. Knowledge of how age and pregnancy influence the dynamics of type 1 and type 2 IR bias is expected to improve our ability to select animals with enhanced immune responsiveness and aid in the development of effective vaccines through strategic targeting of vaccine components to recipients.
选择生产性状而几乎不强调健康性状，导致加拿大奶牛群疾病发病率的增加。我们在这里描述了一种专利协议，用于估计后备奶牛的免疫反应性的育种值，该协议结合了细胞介导（CM）和抗体介导（AM）免疫反应（IR）的测量。分别用于诱导 CMIR 和 AMIR 的假定 1 型和 2 型抗原的能力在替代荷斯坦奶牛中进行了评估，并估计了年龄和妊娠对 1 型和 2 型 IR 偏倚的影响。结果表明，1 型和 2 型抗原诱导了后备奶牛中极化的 1 型和 2 型反应，无论年龄和妊娠状态如何，因此可以用于识别具有优越整体免疫反应性的动物。然而，年龄和妊娠状态对适应性 IR 谱有显著影响，这突出表明在对动物进行 CM 和 AMIR 能力排名时，需要对这些影响进行适当的统计建模。随着后备奶牛接近 12 月龄，反应变得越来越偏向 1 型，从那时起，随着年龄和妊娠时间的延长，反应变得越来越偏向 2 型。了解年龄和妊娠如何影响 1 型和 2 型 IR 偏倚的动态，有望提高我们选择具有增强免疫反应性的动物的能力，并通过将疫苗成分有针对性地靶向接受者来帮助开发有效的疫苗。
