Department of Poultry Science, University of Georgia, Athens, GA.
Department of Poultry Science, University of Georgia, Athens, GA.
Poult Sci. 2022 Nov;101(11):102083. doi: 10.1016/j.psj.2022.102083. Epub 2022 Jul 30.
A study was aimed to investigate the effects of mixed Eimeria challenge on performance, gastrointestinal health, oxidative stress, inflammation, and expression of nutrient transporter genes of Hy-Line W-36 pullets. A total of 540, 16-d old pullets were randomly allocated into 5 treatment groups with 6 replicate cages, including a nonchallenged control group. A mixed Eimeria species solution containing 50,000 E. maxima, 50,000 E. tenella, and 250,000 E. acervulina oocysts per mL was prepared and challenged to one group as a high-dose treatment (High). The 2-fold serial dilution was done to prepare the medium-high (Med-High: 25,000 E. maxima; 25,000 E. tenella; and 125,000 E. acervulina), the medium-low (Med-Low: 12,500 E. maxima; 12,500 E. tenella; and 62,500 E. acervulina), and the low (Low: 6,250 E. maxima; 6,250 E. tenella; and 31,250 E. acervulina) dose treatments, and these dosages were challenged to 3 remaining groups, respectively. Growth performance, daily feed intake (FI), and mortality were calculated from 0-14 d postinfection (DPI). Gastrointestinal permeability (GP) was measured on 3, 5, 6, 7, and 9 DPI. The result indicated significant linear responses to the Eimeria challenge dosage in average body weight and body weight gain (P < 0.0001). An interaction between treatment and DPI was observed for FI (P < 0.0001). Feed intake significantly dropped from 4 DPI and did not recover until 12 DPI in the challenged groups. The lowest FI for each of the challenged groups was observed on 5 DPI. Gastrointestinal permeability increased linearly, peaking at 5 DPI, and was recovered back to normal by 9 DPI in the challenged groups. Furthermore, gene expression of tight junction proteins was linearly upregulated by increased Eimeria dosages. The oxidative status of the pullets was lowered in the challenged groups than the nonchallenged control group, whereas the expression of inflammatory and proinflammatory cytokines was upregulated by Eimeria challenge on 6 DPI (P < 0.05). The highest mortality was observed in pullets challenged with the High, followed by the Med-High (P < 0.0001) on 5 DPI. In summary, the mixed Eimeria challenge linearly reduced the growth performance of pullets with an increase in oxidative stress and inflammation. A severe effect of Eimeria on gastrointestinal health was observed on 5 or 6 DPI as suggested by GP, tight junction genes, and mortality results. This study indicates that Eimeria infection can be a threat to gastrointestinal health related issues in pullets.
一项研究旨在探讨混合艾美耳球虫攻毒对 Hy-Line W-36 母鸡生产性能、胃肠道健康、氧化应激、炎症和营养转运体基因表达的影响。将 540 只 16 日龄母鸡随机分配到 5 个处理组的 6 个重复笼中，包括一个非攻毒对照组。制备含 50,000 个最大艾美耳球虫、50,000 个柔嫩艾美耳球虫和 250,000 个堆型艾美耳球虫卵囊/mL 的混合艾美耳球虫溶液，并对一组进行高剂量攻毒（High）。通过 2 倍系列稀释制备中高剂量（Med-High：25,000 个最大艾美耳球虫、25,000 个柔嫩艾美耳球虫和 125,000 个堆型艾美耳球虫）、中低剂量（Med-Low：12,500 个最大艾美耳球虫、12,500 个柔嫩艾美耳球虫和 62,500 个堆型艾美耳球虫）和低剂量（Low：6,250 个最大艾美耳球虫、6,250 个柔嫩艾美耳球虫和 31,250 个堆型艾美耳球虫）处理，并将这些剂量分别攻毒给另外 3 个组。从攻毒后 0-14 天（DPI）计算生长性能、每日采食量（FI）和死亡率。在 3、5、6、7 和 9 DPI 时测量胃肠道通透性（GP）。结果表明，艾美耳球虫攻毒剂量对平均体重和体重增重有显著的线性响应（P < 0.0001）。处理和 DPI 之间存在 FI 的交互作用（P < 0.0001）。攻毒组从 4 DPI 开始采食量明显下降，直到 12 DPI 才恢复。攻毒组每个攻毒组的最低 FI 均在 5 DPI 观察到。胃肠道通透性呈线性增加，在 5 DPI 时达到峰值，并在攻毒组中在 9 DPI 时恢复正常。此外，紧密连接蛋白基因的表达被线性上调，随艾美耳球虫剂量的增加而增加。攻毒组母鸡的氧化状态低于非攻毒对照组，而在 6 DPI 时，艾美耳球虫攻毒引起炎症和促炎细胞因子的表达上调（P < 0.05）。在 5 DPI 时，死亡率最高的是接受高剂量攻毒的母鸡，其次是接受中高剂量攻毒的母鸡（P < 0.0001）。总之，混合艾美耳球虫攻毒可降低母鸡的生长性能，增加氧化应激和炎症。GP、紧密连接基因和死亡率结果表明，在 5 或 6 DPI 时，艾美耳球虫对胃肠道健康有严重影响。本研究表明，艾美耳球虫感染可能对母鸡的胃肠道健康相关问题构成威胁。
