Comparative effects of dietary zinc nanoparticle and conventional zinc supplementation on broiler chickens: A meta-analysis

Abstract

Background and Aim: Zinc (Zn) is important for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. The gastrointestinal absorption of Zn in broiler chickens was notably low. One approach that has been explored for enhancing the bioavailability of Zn is the development of Zn nanoparticles (NPs). Zn is required for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. Therefore, this study aimed to assess the impact of conventional Zn and Zn NPs on broiler chickens using a meta-analysis methodology. Materials and Methods: A database was built from published literature to evaluate the effects of the addition of Zn NPs and conventional Zn on broiler chicken responses, including the following parameters: production performance; carcass cuts; visceral organ weight; lymphoid organ weight; nutrient digestibility; intestinal villi; mineral Zn, calcium, and phosphorus concentrations; hematology; blood parameters; immunoglobulin; and intestinal bacterial population. Various scientific platforms, including Scopus, Web of Science, PubMed Central, and Google Scholar, were used to search for peer-reviewed articles. A database was created from 25 studies that met the inclusion criteria. The data were then processed for a meta-analysis using a mixed-model methodology. Different types of Zn (NPs versus conventional) were considered fixed effects, different studies were treated as random effects, and p-values were used as model statistics. Results: Across the parameters observed in this study, the use of Zn NPs was more efficient in Zn utilization than conventional Zn, as evidenced by the average dose of Zn NPs being much lower than that of conventional Zn (79.44 vs. 242.76 mg/kg) yet providing similar (p > 0.05) or even significantly better effects (p < 0.05) compared to conventional Zn usage. Conclusion: This investigation revealed the beneficial influence of Zn NPs in broiler chickens compared to the conventional utilization of Zn through an all-encompassing meta-analysis. Moreover, Zn NPs have proven to be more effective in Zn utilization when juxtaposed with conventional Zn, as demonstrated by the significantly lower quantity of Zn NPs administered compared to conventional Zn, while yielding comparable or even superior outcomes compared to the traditional utilization of Zn. A limitation of this study is that the Zn NPs used were sourced from inorganic Zn NPs. Therefore, future research should focus on evaluating the efficiency of organic Zn NPs in broiler chicken feed. Keywords: broiler chicken, conventional zinc, performance, welfare indices, zinc nanoparticles.