Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Animal. 2013 Jan;7(1):151-9. doi: 10.1017/S175173111200136X. Epub 2012 Jul 6.
In recent years, livestock producers have been supplementing animal diets with fish meal (FM) to produce value-added products for health conscious consumers. As components of FM have unique neuroendocrine-immunomodulatory properties, we hypothesize that livestock producers may be influencing the overall health of their animals by supplementing diets with FM. In this study, 40 pregnant ewes were supplemented with rumen protected (RP) soybean meal (SBM: control diet) or RP FM, commencing gestation day 100 (gd100), in order to evaluate the impact of FM supplementation on the innate and acquired immune response and neuroendocrine response of sheep during pregnancy and lactation. On gd135, half the ewes from each diet (n = 10 FM, n = 10 SBM) were challenged iv with lipopolysaccharide (LPS) to simulate a systemic bacterial infection and the febrile, respiratory and neuroendocrine responses were monitored over time; the other half (n = 10 FM, n = 10 SBM) of the ewes received a saline injection as control. On lactation day 20 (ld20), all ewes (n = 20 FM, n = 20 SBM) were sensitized with hen egg white lysozyme (HEWL) and the serum haptoglobin (Hp) response was measured over time. The cutaneous hypersensitivity response (CHR) to HEWL challenge was measured on ld30 (n = 20 FM, n = 20 SBM), and blood samples were collected over time to measure the primary and secondary immunoglobulin G (IgG) response to HEWL. There was an attenuated trend in the LPS-induced febrile response by the FM treatment when compared with the SBM treatment (P = 0.06), as was also true for the respiratory response (P = 0.07), but significant differences in neuroendocrine function (serum cortisol and plasma ACTH) were not observed between treatments. Basal Hp levels were significantly lower in the FM supplemented ewes when compared with the SBM supplemented ewes (P < 0.01), and the Hp response to HEWL sensitization differed significantly over time between treatments (P < 0.01). The CHR to HEWL was also significantly attenuated in the FM treatment compared with the SBM (P < 0.01); however, treatment differences in the primary and secondary IgG responses to HEWL were not observed. These results indicate that FM supplementation differentially affects the innate and acquired immune responses in pregnant and lactating sheep compared with a typical SBM diet of commercial flocks. The long-term implications of this immunomodulation warrant further investigation.
近年来，畜牧业生产者一直在向动物饲料中添加鱼粉（FM），以生产出有益于健康的消费者的增值产品。由于 FM 的成分具有独特的神经内分泌-免疫调节特性，我们假设畜牧业生产者通过在饮食中添加 FM 可能会影响动物的整体健康。在这项研究中，40 只怀孕母羊从妊娠第 100 天（gd100）开始补充瘤胃保护（RP）大豆粉（SBM：对照饮食）或 RP FM，以评估 FM 补充对绵羊在妊娠和哺乳期的固有和获得性免疫反应和神经内分泌反应的影响。在 gd135 时，每个饮食组的一半母羊（n = 10 FM，n = 10 SBM）静脉内注射脂多糖（LPS）以模拟全身细菌感染，并随时间监测发热、呼吸和神经内分泌反应；另一半母羊（n = 10 FM，n = 10 SBM）接受生理盐水注射作为对照。在哺乳期第 20 天（ld20），所有母羊（n = 20 FM，n = 20 SBM）用鸡卵清白溶菌酶（HEWL）致敏，并随时间测量血清结合珠蛋白（Hp）反应。在 ld30 时测量对 HEWL 挑战的皮肤超敏反应（CHR）（n = 20 FM，n = 20 SBM），并随时间采集血液样本测量对 HEWL 的原发性和次级免疫球蛋白 G（IgG）反应。与 SBM 处理相比，FM 处理的 LPS 诱导的发热反应呈减弱趋势（P = 0.06），呼吸反应也呈减弱趋势（P = 0.07），但两种处理之间的神经内分泌功能（血清皮质醇和血浆 ACTH）没有显著差异。与 SBM 补充的母羊相比，FM 补充的母羊的基础 Hp 水平明显降低（P < 0.01），HEWL 致敏的 Hp 反应在不同时间处理之间差异显著（P < 0.01）。与 SBM 相比，FM 处理的 HEWL 皮肤超敏反应也明显减弱（P < 0.01）；然而，对 HEWL 的原发性和次级 IgG 反应的处理差异没有观察到。这些结果表明，与商业羊群的典型 SBM 饮食相比，FM 补充会对妊娠和哺乳期绵羊的固有和获得性免疫反应产生不同的影响。这种免疫调节的长期影响值得进一步研究。
