Zhang Fan, Yang Jiantao, Zhan Qinyi, Shi Hao, Li Yanhe, Li Dinggang, Li Yingge, Yang Xiaojun
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
Baoding Jizhong Pharmaceutical Corporation, LTD, Baoding, Hebei, China.
J Anim Sci Biotechnol. 2023 Sep 1;14(1):77. doi: 10.1186/s40104-023-00857-w.
Intestinal health plays a pivotal role in broiler chicken growth. Oregano aqueous extract (OAE) effectively exerts anti-inflammatory and antibacterial effects. However, the protective effects of OAE on intestinal health in broilers and the underlying mechanism remain unclear. This study aimed to investigate the potential effects of OAE on growth performance, the gut microbiota and intestinal health. A total of 840 1-d-old male and female broilers (Arbor Acres) were randomly allocated into 6 groups as follows: basal diet (Con), Con + antibiotics (Anti, colistin sulfate 7 g/kg, roxarsone 35 g/kg), Con + 400, 500, 600 and 700 mg/kg OAE (OAE400, OAE500, OAE600 and OAE700). Subsequently, fermentation in vitro together with oral administration trials were carried out to further assess the function of OAE on intestinal health of broilers.
Dietary 700 mg/kg OAE supplementation resulted in an increase (P < 0.05) in body weight and a decrease (P < 0.05) in feed conversion ratio when compared with the control during d 22 to 42 of the trial. OAE addition resulted in lower (P < 0.05) jejunal crypt depth and mRNA expression of IL-4 and IL-10 at d 42. In addition, dietary OAE addition increased the abundance of Firmicutes (P = 0.087) and Lactobacillus (P < 0.05) in the cecum, and increased (P < 0.05) the content of acetic acid and butyric acid. In the in vitro fermentation test, OAE significantly increased (P < 0.05) the abundance of Lactobacillus, decreased (P < 0.05) the abundance of unspecified_Enterobacteriaceae, and increased the content of acetic acid (P < 0.05). In the oral administration trial, higher (P < 0.05) IL-4 expression was found in broilers when oral inoculation with oregano fermentation microorganisms at d 42. And SIgA content in the ileum was significantly increased (P = 0.073) when giving OAE fermentation supernatant.
Dietary OAE addition could maintain intestinal health and improve growth performance through enhancing intestinal mucosal immunity and barrier function mediated by gut microbiota changes.
肠道健康对肉鸡生长起着关键作用。牛至水提取物（OAE）能有效发挥抗炎和抗菌作用。然而，OAE对肉鸡肠道健康的保护作用及其潜在机制仍不清楚。本研究旨在探讨OAE对生长性能、肠道微生物群和肠道健康的潜在影响。总共840只1日龄的雄性和雌性肉鸡（艾维茵）被随机分为6组，如下：基础日粮（Con）、Con +抗生素（Anti，硫酸黏菌素7 g/kg，洛克沙胂35 g/kg）、Con + 400、500、600和700 mg/kg OAE（OAE400、OAE500、OAE600和OAE700）。随后，进行体外发酵和口服给药试验，以进一步评估OAE对肉鸡肠道健康的作用。
在试验的第22至42天，与对照组相比，日粮中添加700 mg/kg OAE可使体重增加（P < 0.05），饲料转化率降低（P < 0.05）。添加OAE可使第42天时空肠隐窝深度以及IL-4和IL-10的mRNA表达降低（P < 0.05）。此外，日粮中添加OAE可增加盲肠中厚壁菌门丰度（P = 0.087）和乳酸杆菌丰度（P < 0.05），并增加乙酸和丁酸含量（P < 0.05）。在体外发酵试验中，OAE显著增加了乳酸杆菌丰度（P < 0.05），降低了未指定的肠杆菌科丰度（P < 0.05），并增加了乙酸含量（P < 0.05）。在口服给药试验中，第42天给肉鸡口服接种牛至发酵微生物时，发现IL-4表达较高（P < 0.05）。给予OAE发酵上清液时，回肠中分泌型免疫球蛋白A（SIgA）含量显著增加（P = 0.073）。
日粮中添加OAE可通过增强肠道黏膜免疫和由肠道微生物群变化介导的屏障功能来维持肠道健康并改善生长性能。
