Madsen Mette D, van der Werf Julius H J, Ingham Aaron, Hine Brad, Reverter Antonio, Clark Sam A
School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.
Queensland Biosecurity Precinct, Agriculture & Food, CSIRO, St Lucia, QLD, 4067, Australia.
Genet Sel Evol. 2025 Sep 25;57(1):47. doi: 10.1186/s12711-025-00998-8.
Improving immune competence (IC) in livestock could reduce the incidence of disease and reliance on the use of antibiotics. In Australian Angus cattle, IC is a measure of an animal's combined ability to mount antibody and cell-mediated immune responses (AMIR and CMIR). Immune competence may affect traits such as growth and related phenotypes as well as the variability of such phenotypes. However, the genetic relationship between IC and genetic sensitivity to individual environments, measured as micro-genetic environmental sensitivity (GES), is yet to be reported. In this study the genetic parameters of, and correlations between, AMIR or CMIR and micro-GES of live weaning weight (WW) and ultrasound scan records of rib (RIB) and rump (RUMP) fat depth and eye muscle area (EMA) measured between 501 and 900 days of age were estimated. This was accomplished by fitting eight multivariate models with AMIR or CMIR and a double hierarchical generalised linear model on a production trait.
The heritabilities were 0.35 and 0.36 for AMIR and CMIR, respectively, and 0.25-0.70 for the production traits. The heritabilities and the genetic coefficient of variation of micro-GES of the production traits ranged from 0.01-0.04 and 18-82%, respectively, and were higher in RIB and RUMP than WW and EMA. The genetic correlations between AMIR and WW, RIB, RUMP, or EMA were -0.35 (SE 0.11), 0.11 (0.12), 0.06 (0.12) and -0.13 (0.12), respectively, while the genetic correlations between CMIR and WW, RIB, RUMP, or EMA were -0.26 (0.12), 0.15 (0.13), 0.16 (0.12) and 0.04 (0.13), respectively. The genetic correlations between IC and micro-GES of WW, RIB, RUMP or EMA were moderately negative to lowly positive and had large SEs rendering them non-significant.
The unfavourable genetic correlation between the IC traits and WW supports the hypothesis that mounting an effective immune response can direct resources away from growth when resources are limited. Based on the heritabilities and genetic coefficient of variation of micro-GES, selection to increase uniformity is possible for WW, RIB, RUMP and EMA. The standard errors of the genetic correlations between IC and micro-GES of the production traits were too large to draw any definite conclusions about their relationships. Standard errors are expected to reduce as more IC records are collected.
提高家畜的免疫能力（IC）可降低疾病发生率并减少对抗生素的依赖。在澳大利亚安格斯牛中，IC是衡量动物产生抗体和细胞介导免疫反应（AMIR和CMIR）的综合能力。免疫能力可能会影响生长及相关表型等性状以及这些表型的变异性。然而，IC与以微基因环境敏感性（GES）衡量的个体环境遗传敏感性之间的遗传关系尚未见报道。本研究估计了501至900日龄之间活体断奶体重（WW）的AMIR或CMIR与微GES以及肋骨（RIB）、臀部（RUMP）脂肪深度和眼肌面积（EMA）的超声扫描记录之间的遗传参数及其相关性。这是通过对AMIR或CMIR拟合八个多变量模型以及对生产性状拟合双层次广义线性模型来实现的。
AMIR和CMIR的遗传力分别为0.35和0.36，生产性状的遗传力为0.25 - 0.70。生产性状微GES的遗传力和遗传变异系数分别为0.01 - 0.04和18 - 82％，RIB和RUMP中的高于WW和EMA。AMIR与WW、RIB、RUMP或EMA之间的遗传相关性分别为 - 0.35（标准误0.11）、0.11（0.12）、0.06（0.12）和 - 0.13（0.12），而CMIR与WW、RIB、RUMP或EMA之间的遗传相关性分别为 - 0.26（0.12）、0.15（0.13）、0.16（0.12）和0.04（0.13）。IC与WW、RIB、RUMP或EMA的微GES之间的遗传相关性为中度负至低度正，且标准误较大，使其不显著。
IC性状与WW之间不利的遗传相关性支持了以下假设：当资源有限时，产生有效的免疫反应会使资源从生长中转移。基于微GES的遗传力和遗传变异系数，对于WW、RIB、RUMP和EMA，可以通过选择来提高均匀性。生产性状的IC与微GES之间遗传相关性的标准误太大，无法就它们之间的关系得出任何明确结论。随着收集到更多的IC记录，预计标准误将会降低。
