Hervé Julie, Terenina Elena, Haurogné Karine, Bacou Elodie, Kulikova Elizaveta, Allard Marie, Billon Yvon, Bach Jean-Marie, Mormède Pierre, Lieubeau Blandine
IECM, INRA, Oniris, La Chantrerie, CS 40706, F-44307, Nantes Cedex 3, France.
GenPhySE, Université de Toulouse, INRA, INPT, ENVT, F-31326, Castanet-Tolosan, France.
BMC Vet Res. 2019 Mar 4;15(1):71. doi: 10.1186/s12917-019-1809-9.
The sustainability of farming and animal welfare requires the reconsideration of current selection schemes. In particular, implementation of new selection criteria related to animal health and welfare should help to produce more robust animals and to reduce anti-microbial use. The hypothalamo-pituitary-adrenocortical (HPA) axis plays a major role in metabolic regulation and adaptation processes and its activity is strongly influenced by genetic factors. A positive association between HPA axis activity and robustness was recently described. To explore whether selecting pigs upon HPA axis activity could increase their robustness, a divergent selection experiment was carried out in the Large White pig breed. This allowed the generation of low (HPA) and high (HPA) responders to adrenocorticotropic hormone administration.
In this study, we compared 23 hematologic and immune parameters of 6-week-old, HPA and HPA piglets and analysed their response to a low dose of lipopolysaccharide (LPS) two weeks later. At six weeks of age, HPA piglets displayed greater red blood cell and leucocyte number including CD8α γδ cells, cytotoxic T lymphocytes, naive T helper (Th) cells and B lymphocytes as compared to HPA individuals. The ability of blood cells to secrete TNFα in response to LPS ex vivo was higher for HPA pigs. At week eight, the inflammatory response to the LPS in vivo challenge was poorly affected by the HPA axis activity.
Divergent selection upon HPA axis activity modulated hematologic and immune parameters in 6-week-old pigs, which may confer an advantage to HPA pigs at weaning. However, HPA and HPA piglets did not exhibit major differences in the parameters analysed two weeks later, i. e. in 8-week-old pigs. In conclusion, chronic exposure to high cortisol levels in HPA pigs does not negatively impact immunity.
农业的可持续性和动物福利要求重新审视当前的选择方案。特别是，实施与动物健康和福利相关的新选择标准应有助于培育出更强壮的动物，并减少抗菌药物的使用。下丘脑-垂体-肾上腺皮质（HPA）轴在代谢调节和适应过程中起主要作用，其活性受遗传因素的强烈影响。最近有研究描述了HPA轴活性与强壮性之间存在正相关。为了探究根据HPA轴活性选择猪是否能提高其强壮性，在大白猪品种中进行了一项分化选择实验。这使得能够产生对促肾上腺皮质激素给药反应低（HPA）和高（HPA）的猪。
在本研究中，我们比较了6周龄HPA和HPA仔猪的23项血液学和免疫参数，并在两周后分析了它们对低剂量脂多糖（LPS）的反应。6周龄时，与HPA个体相比，HPA仔猪的红细胞和白细胞数量更多，包括CD8αγδ细胞、细胞毒性T淋巴细胞、初始T辅助（Th）细胞和B淋巴细胞。HPA猪的血细胞在体外对LPS分泌TNFα的能力更高。在第8周时，体内LPS刺激的炎症反应受HPA轴活性的影响较小。
根据HPA轴活性进行分化选择可调节6周龄猪的血液学和免疫参数，这可能使HPA猪在断奶时具有优势。然而，HPA和HPA仔猪在两周后（即8周龄猪）分析的参数中没有表现出主要差异。总之，HPA猪长期暴露于高皮质醇水平对免疫力没有负面影响。
