Wang Y, Puntenney S B, Burton J L, Forsberg N E
1Department of Animal Sciences, Oregon State University, Corvallis, OR 97331-6702, USA.
Animal. 2007 Aug;1(7):945-51. doi: 10.1017/S1751731107000365.
In the first study, we tested the ability of a commercial feed additive (OmniGen-AF) to affect markers of innate immunity in immunosuppressed sheep and the ability of a pathogen challenge (mould) to affect the immune response to the additive. Treatments consisted of (1) control, (2) immunosuppressed with dexamethasone (DEX), (3) immunosuppressed plus the feed additive, (4) immunosuppressed plus Aspergillus fumigatus and (5) immunosuppressed, A. fumigatus and the additive. Animal health was monitored and indexes of innate immunity (neutrophil L-selectin and interleukin-1β (IL-1β)) were collected. DEX caused immunosuppression (i.e. reduced abundance of neutrophil L-selectin and IL-1β). This immunosuppressive effect was countered by the provision of the additive in the ration. Provision of mould in the ration increased the ability of the additive to regulate markers of innate immune function. A second study was completed to re-assess the properties of the additive and other feed products. The study consisted of seven treatments: (1) immunosuppressed, (2) immunosuppressed with additive, (3) immunosuppressed with additive in pelleted form (low-temperature pellet) and (4) immunosuppressed with additive in a high-temperature pellet. The remaining three treatments assessed abilities of three other additives to regulate markers of innate immune function. In this study, OmniGen-AF increased expression of neutrophil L-selectin abundance in immunosuppressed animals and this was unaffected by the pelleting temperature. None of the other additives affected markers of innate immunity. In these studies we discovered mechanisms by which a feed product may affect the immune function of ruminant livestock. The product countered DEX-dependent down-regulation of markers of innate immune function and its actions were enhanced by the presence of pathogen (mould) in the ration.
在第一项研究中，我们测试了一种商业饲料添加剂（OmniGen - AF）对免疫抑制绵羊先天免疫标志物的影响，以及病原体攻击（霉菌）对该添加剂免疫反应的影响。处理组包括：（1）对照组，（2）用地塞米松（DEX）免疫抑制组，（3）免疫抑制加饲料添加剂组，（4）免疫抑制加烟曲霉组，以及（5）免疫抑制、烟曲霉和添加剂组。监测动物健康状况并收集先天免疫指标（中性粒细胞L - 选择素和白细胞介素 - 1β（IL - 1β））。DEX导致免疫抑制（即中性粒细胞L - 选择素和IL - 1β丰度降低）。日粮中添加该添加剂可对抗这种免疫抑制作用。日粮中添加霉菌可增强添加剂调节先天免疫功能标志物的能力。第二项研究旨在重新评估该添加剂及其他饲料产品的特性。该研究包括七种处理：（1）免疫抑制组，（2）免疫抑制加添加剂组，（3）免疫抑制加颗粒状添加剂组（低温颗粒），以及（4）免疫抑制加高温颗粒状添加剂组。其余三种处理评估了其他三种添加剂调节先天免疫功能标志物的能力。在这项研究中，OmniGen - AF增加了免疫抑制动物中性粒细胞L - 选择素的表达丰度，且这不受制粒温度的影响。其他添加剂均未影响先天免疫标志物。在这些研究中，我们发现了一种饲料产品可能影响反刍家畜免疫功能的机制。该产品对抗了依赖DEX的先天免疫功能标志物下调，且日粮中病原体（霉菌）的存在增强了其作用。
