Husseini Nasrin, Beard Shannon C, Hodgins Douglas C, Barnes Christy, Chik Elfleda, Mallard Bonnie A
Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Bennett Equine Veterinary Services, Cambridge, Ontario, N1T 1T1, Canada.
Transl Anim Sci. 2022 Jan 27;6(1):txac006. doi: 10.1093/tas/txac006. eCollection 2022 Jan.
The high immune response (HIR) methodology measures the genetic performance of the adaptive immune system to identify and breed animals with balanced and robust immunity. The HIR methodology has previously been used in dairy and swine to reduce disease but has not been fully investigated in beef cattle. The first objective of the current study was to examine whether the HIR methodology as standardized for use in dairy cattle was appropriate for use in beef cattle. The second objective was to determine the earliest age for immune response phenotyping of beef calves. In this study, beef calves ( = 295) of various ages, as well as mature beef cows ( = 170) of mixed breeds, were immunized using test antigens to assess their antibody- (AMIR) and cell-mediated immune responses (CMIR). Heritability for AMIR and CMIR was estimated at 0.43 and 0.18, respectively. The HIR methodology was appropriate for use in beef cattle; beef calves as young as 2-3 wk of age were capable of mounting AMIR responses comparable with those seen historically in mature Holstein dairy cows. Three-week-old beef calves mounted CMIR responses comparable with those of Holstein cows, but 9-mo-old calves and mature beef cows had significantly higher CMIR responses than Holsteins. The HIR methodology can be used to measure both AMIR and CMIR in beef calves as young as 3 wk of age.
高免疫反应（HIR）方法可衡量适应性免疫系统的遗传性能，以识别和培育具有平衡且强大免疫力的动物。HIR方法此前已用于奶牛和猪以减少疾病，但在肉牛中尚未得到充分研究。本研究的首要目标是检验用于奶牛的标准化HIR方法是否适用于肉牛。第二个目标是确定肉牛犊免疫反应表型分析的最早年龄。在本研究中，使用测试抗原来评估不同年龄的肉牛犊（n = 295）以及混种成年肉牛母牛（n = 170）的抗体介导免疫反应（AMIR）和细胞介导免疫反应（CMIR）。AMIR和CMIR的遗传力估计分别为0.43和0.18。HIR方法适用于肉牛；年仅2 - 3周龄的肉牛犊能够产生与历史上成熟荷斯坦奶牛相当的AMIR反应。3周龄的肉牛犊产生的CMIR反应与荷斯坦奶牛相当，但9月龄犊牛和成年肉牛母牛的CMIR反应显著高于荷斯坦奶牛。HIR方法可用于测量年仅3周龄的肉牛犊的AMIR和CMIR。
