Meta-analyses of the global impact of non-antibiotic feed additives on livestock performance and health

Abstract

Introduction

The impact of non-antibiotic feed additives on livestock performance and health is contingent upon a multitude of variables, including the animal species, dosage and type of feed additives, and duration of oral administration. However, there is a paucity of knowledge regarding the relationship between these factors and the performance of livestock animals.

Objectives

The objective of this study was to conduct a global meta-analysis based on a pool of empirical studies to investigate the effects of dietary additives on growth, production, blood metabolites, immunity, intestinal morphology, and the abundance of gut microbiota in livestock.

Methods

A meta-regression coupled with dose–effect analysis was performed to ascertain the optimal dosage and feeding duration for the optimal body function. A total of 71 papers, estimating 1, 035 effect size across 9 species and 7 types of non-antibiotic feed additives were recruited in our meta-dataset.

Results

Overall assessment confirmed that these additives in diet can significantly improve livestock production and immune function across species. Our findings indicated that the effects of additives on animal performance were more pronounced in herbivores than in omnivores. The dose–response results indicated that the overall optimal doses for antimicrobial peptides, enzymes, oligosaccharides, organic acids, phytogenic, probiotics and prebiotics were 100 mg/kg, 30 mg/kg, 200 mg/kg, 50 mg/kg, 200 mg/kg, 10⁶ CFU/kg, and 10 mg/kg, respectively. Oral administration of these additives for a 2-month period effectively improves livestock performance and health.

Conclusion

This evidence-based approach provides a foundation for implementing customized feeding strategies designed to optimize livestock performance, enhance immunity and reduce feed costs. Our assessment shows that these feed additives are promising alternatives to antibiotics in reducing the use of antibiotics. Furthermore, these findings suggest that the use of these feed additives can lead to evidence-based recommendations for practical feeding strategies, providing livestock producers with a sustainable and cost-effective approach to animal health management.