State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
Feed Safety and Healthy Livestock, Beijing Jingwa Agricultural Innovation Center, Beijing, China.
Front Immunol. 2022 Aug 9;13:928865. doi: 10.3389/fimmu.2022.928865. eCollection 2022.
The aim of this study was to evaluate the effects of different selenium (Se) sources on the immune responses and gut microbiota of laying hens challenged with (). A total of 240 45-week-old layers were randomly divided into eight groups with six replicates per group according to a 4 × 2 factorial design, including a blank diet without Se supplementation (CON group) and three diets with 0.3 mg/kg Se supplementation from sodium selenite (IS group), yeast Se (YS group), and selenium-enriched yeast culture (SYC group), respectively. After 8 weeks of feeding, half of them were orally challenged with 1.0 ml suspension of 10 colony-forming units per milliliter of daily for 3 days. The serum was collected on days 3, 7, and 14, and the cecum content was collected on day 14 after challenge. There was no significant difference in laying performance among the eight groups before challenge. The challenge significantly decreased the laying performance, egg quality, GSH-Px, IgG, and IgM and increased the ratio of feed and egg, malondialdehyde (MDA), -specific antibody (SA) titers, IL-6, IL-2, IL-1β, and INF-γ. However, SYC increased the level of GSH-Px and IgG and decreased IL-6, while YS decreased the level of IL-2 and IL-1β. What is more, Se supplementation decreased the SA titers to varying degrees and reduced the inflammatory cell infiltration in the lamina propria caused by infection. In addition, the challenge disrupted the intestinal flora balance by reducing the abundance of the genera , , and and increasing the genera and , while Se supplementation increased the gut microbial alpha diversity whether challenged or not. Under the challenge condition, the alteration of microbial composition by the administration of different Se sources mainly manifested as IS increased the relative abundance of the genera and , YS increased the relative abundance of the genera and , and SYC increased the genera and . The alteration of gut microbial composition had a close relationship with antioxidant or immune response. To summarize, different Se sources can improve the egg quality of layers challenged by that involves elevating the immunity level and regulating the intestinal microbiota.
本研究旨在评估不同硒（Se）源对感染 （）的产蛋鸡免疫反应和肠道微生物群的影响。将 240 只 45 周龄的蛋鸡随机分为 8 组，每组 6 个重复，采用 4×2 因子设计，包括不含硒的空白饮食（CON 组）和 3 种日粮，分别补充 0.3mg/kg 亚硒酸钠（IS 组）、酵母硒（YS 组）和富硒酵母培养物（SYC 组）。饲养 8 周后，其中一半鸡用 1.0ml 含 10 个菌落形成单位/毫升的 混悬液经口攻毒 3 天。攻毒后第 3、7 和 14 天采集血清，第 14 天采集盲肠内容物。攻毒前，8 组鸡的产蛋性能无显著差异。 感染显著降低了产蛋性能、蛋品质、GSH-Px、IgG 和 IgM，增加了料蛋比、丙二醛（MDA）、-特异性抗体（SA）滴度、IL-6、IL-2、IL-1β和 INF-γ。然而，SYC 增加了 GSH-Px 和 IgG 的水平，降低了 IL-6，YS 则降低了 IL-2 和 IL-1β的水平。更重要的是，硒补充剂在不同程度上降低了 SA 滴度，并减轻了 感染引起的固有层炎症细胞浸润。此外，硒补充剂无论是否受到 感染的挑战，都增加了肠道微生物 alpha 多样性。在 感染的情况下，不同硒源对肠道微生物组成的改变主要表现为 IS 增加了 、 和 的相对丰度，YS 增加了 、 和 的相对丰度，SYC 增加了 、 和 的相对丰度。肠道微生物组成的改变与抗氧化或免疫反应密切相关。总之，不同的硒源可以改善 感染的蛋鸡的蛋品质，涉及提高免疫水平和调节肠道微生物群。
