Controlling piglet post-weaning diarrhea using nanotechnology-empowered zinc oxide at low doses
Loading...
Date
2021
Authors
Wang, Lucy
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Zinc oxide is used in the swine industry as an antibiotic-alternative, to protect piglets against Escherichia coli infections during the post-weaning period. The global overuse of zinc oxide in piglet feed is currently a major concern in the swine industry. The post-weaning period is a markedly sensitive period for piglets that is often characterized by illness, commonly diarrhea caused by enterotoxigenic E. coli (ETEC F4). There are several issues around the use of high doses of zinc oxide, of which environmental pollution is a major consideration. As a response to this concern, this research focuses on a targeted zinc oxide delivery approach by encapsulating zinc oxide in a physiologically active material. This preserves the antimicrobial activity of zinc oxide, while reducing overuse, and the mitigating the negative environmental impacts. Three zinc oxide encapsulated delivery vehicles were fabricated: ZnO-HET (whey protein, sodium alginate, and zinc oxide in a heterogenous mix); ZnO-SW (whey protein and sodium alginate shell encapsulating a zinc oxide core); and ZnO-L100 (commercial EUDRAGIT® L100 shell encapsulating a zinc oxide core). The zinc oxide release profiles were assessed under in vitro conditions, and in extracted digestive fluids. In both situations, ZnO-L100 demonstrated the most effective targeted delivery of zinc oxide to the intestinal environment, which is the area where ETEC F4 would physiologically colonize and infect in the post-weaning piglet. ZnO-L100 delivered at least 20% more zinc oxide to the intestinal environment compared to ZnO-HET and ZnO-SW (p < 0.05). As a result of this potential, it was of interest to investigate the antibacterial ability of ZnO-L100. Using the WST-8 microbial viability assay method, we demonstrated that ZnO-L100 had ETEC F4 antibacterial activity within 30 minutes and sustained antibacterial activity beyond 150 minutes. Overall, the ZnO-L100 product was able to demonstrate a responsive release profile favourable to intestinal conditions, as well as the release of sufficient zinc oxide to inhibit ETEC F4. Together these features demonstrated that the encapsulation of zinc oxide can be a viable solution to reduce the industrial practice of high dose zinc oxide, while still retaining its antibacterial properties.
Description
Keywords
Post-weaning diarrhea, Piglets, Nanotechnology, Microencapsulation, Zinc oxide
Citation
Canadian Biosystems Engineering