Ramis Guillermo, Murciano Francisco, Orengo Juan, González-Guijarro Belén, Cuellar-Flores Amanda, Serrano Daniel, Muñoz Luna Antonio, Sánchez-Uribe Pedro, Martínez-Alarcón Laura
Departamento de Producción Animal, Facultad de Veterinaria, Universidad de Murcia, 30100 Murcia, Spain.
Instituto Murciano de Investigación en Biomédicina (IMIB), 30120 Murcia, Spain.
Animals (Basel). 2023 May 25;13(11):1754. doi: 10.3390/ani13111754.
Although zinc oxide has been banned at therapeutic doses in the EU, its use is still legal in most countries with industrial pig farming. This compound has been shown to be very effective in preventing -related diseases. However, another strategy used to control this pathogen is vaccination, administered parenterally or orally. Oral vaccines contain live strains, with F4 and F18 binding factors. Since zinc oxide prevents adhesion, it is hypothesised that its presence at therapeutic doses (2500 ppm) may alter the immune response and the protection of intestinal integrity derived from the vaccination of animals.
A group of piglets were orally vaccinated at weaning and divided into two subgroups; one group was fed a feed containing 2500 ppm zinc oxide (V + ZnO) for the first 15 days post-vaccination (dpv) and the other was not (V). Faeces were sampled from the animals at 6, 8, 11, 13, and 15 dpv. Unvaccinated animals without ZnO in their feed (Neg) were sampled simultaneously and, on day 15 post-vaccination, were also compared with a group of unvaccinated animals with ZnO in their feed (ZnO).
Differences were found in excretion, with less quantification in the V + ZnO group, and a significant increase in secretory IgA in the V group at 8 dpv, which later equalised with that of the V + ZnO group. There was also some difference in , , , , and gene expression when comparing both vaccinated groups ( < 0.05). However, there was no difference in gene expression for the tight junction (TJ) proteins responsible for intestinal integrity.
Although some differences in the excretion of the vaccine strain were found when comparing both vaccinated groups, there are no remarkable differences in immune stimulation or soluble IgA production when comparing animals orally vaccinated against in combination with the presence or absence of ZnO in their feed. We can conclude that the immune response produced is very similar in both groups.
尽管欧盟已禁止在治疗剂量下使用氧化锌，但在大多数工业化养猪的国家，其使用仍然合法。这种化合物已被证明在预防相关疾病方面非常有效。然而，另一种用于控制这种病原体的策略是接种疫苗，通过肠胃外或口服方式给药。口服疫苗包含具有F4和F18结合因子的活菌株。由于氧化锌可防止粘连，因此推测其在治疗剂量（2500 ppm）下的存在可能会改变免疫反应以及动物接种疫苗后对肠道完整性的保护。
一组仔猪在断奶时口服接种疫苗，并分为两个亚组；一组在接种疫苗后的前15天（dpv）喂食含2500 ppm氧化锌的饲料（V + ZnO），另一组则不喂食（V）。在接种疫苗后的第6、8、11、13和15天从动物采集粪便样本。同时对饲料中不含氧化锌的未接种疫苗的动物（Neg）进行采样，并在接种疫苗后的第15天，将其与饲料中含氧化锌的未接种疫苗的动物组（ZnO）进行比较。
在排泄方面发现了差异，V + ZnO组的定量较少，V组在接种疫苗后第8天分泌型IgA显著增加，随后与V + ZnO组持平。比较两个接种疫苗的组时，在、、、和基因表达方面也存在一些差异（<0.05）。然而，负责肠道完整性的紧密连接（TJ）蛋白的基因表达没有差异。
尽管比较两个接种疫苗的组时发现疫苗菌株的排泄存在一些差异，但比较口服接种疫苗的动物与饲料中是否存在氧化锌时，在免疫刺激或可溶性IgA产生方面没有显著差异。我们可以得出结论，两组产生的免疫反应非常相似。
