ZnO NPs are emerging as a promising alternative to traditional feed additives for their antimicrobial, growth-promoting, and immune-regulatory benefits.
The small size of ZnO NPs — typically between one to 100 nanometres — and high surface area gives it high bioavailability compared to conventional zinc oxide and organic zinc compounds.
“These characteristics make ZnO NPs an ideal candidate for replacing antibiotics, particularly in reducing antibiotic use, improving animal health, and enhancing production performance,” the review said.
Previous studies have shown that ZnO NPs inhibit the growth of Escherichia coli and Klebsiella pneumoniae at a concentration of 30 μg/mL.
The review added that ZnO NPs exhibit broad-spectrum antibacterial activity against both gram-positive and gram-negative bacteria.
It has a notably stronger inhibitory effect on gram-negative strains, extending even to heat-resistant and pressure-tolerant spores.
Furthermore, ZnO NPs have demonstrated their potential in improving meat, egg, and milk quality, as well as promoting better nutrient absorption and intestinal health.
Limitations and challenges
The core motivation for exploring the potential of ZnO NPs as an alternative to traditional antibiotics is to combat antibiotic resistance in the livestock industry.
“The overuse of antibiotics has not only led to the spread of resistant bacteria but also poses significant threats to animal health and human food safety. Therefore, finding alternatives to antibiotics has become an urgent issue in animal production.”
Despite the promising applications of ZnO NPs in animal feed to replace antibiotics, several key challenges remain.
Firstly, the optimisation of their dosage is critical to maximise benefits without adverse effects due to overuse.
The researchers also highlighted that long-term safety studies are lacking, particularly regarding potential risks to animal health with prolonged exposure.
Additionally, more information is needed to understand their impact on the environment.
“However, future research should focus on optimising their dosage, enhancing bioavailability, and investigating the mechanisms underlying their antimicrobial efficacy. Moreover, understanding the environmental implications and ensuring the safe, sustainable use of ZnO NPs in animal feed will be essential for their continued application in the livestock industry.”
Furthermore, the current regulatory framework for zinc supplements does not take into account its nanoparticle form.
“Developing safe and effective regulatory frameworks will be crucial to ensure their responsible use and mitigate any potential ecological risks.”
Source: Nanomaterials
Zinc Oxide Nanoparticles as Next-Generation Feed Additives: Bridging Antimicrobial Efficacy, Growth Promotion, and Sustainable Strategies in Animal Nutrition
Authors: Jiayi Yang, Dongwei Xiong and Miao Long
https://doi.org/10.3390/nano15131030
