Implication and challenges of direct-fed microbial supplementation to improve ruminant production and health

Yajing Ban,Le Luo Guan

doi:10.1186/s40104-021-00630-x

Yajing Ban, Le Luo Guan

Open Access

https://doi.org/10.1186/s40104-021-00630-x

Copy DOI

Abstract

Direct-fed microbials (DFMs) are feed additives containing live naturally existing microbes that can benefit animals’ health and production performance. Due to the banned or strictly limited prophylactic and growth promoting usage of antibiotics, DFMs have been considered as one of antimicrobial alternatives in livestock industry. Microorganisms used as DFMs for ruminants usually consist of bacteria including lactic acid producing bacteria, lactic acid utilizing bacteria and other bacterial groups, and fungi containing Saccharomyces and Aspergillus. To date, the available DFMs for ruminants have been largely based on their effects on improving the feed efficiency and ruminant productivity through enhancing the rumen function such as stabilizing ruminal pH, promoting ruminal fermentation and feed digestion. Recent research has shown emerging evidence that the DFMs may improve performance and health in young ruminants, however, these positive outcomes were not consistent among studies and the modes of action have not been clearly defined. This review summarizes the DFM studies conducted in ruminants in the last decade, aiming to provide the new knowledge on DFM supplementation strategies for various ruminant production stages, and to identify what are the potential barriers and challenges for current ruminant industry to adopt the DFMs. Overall literature research indicates that DFMs have the potential to mitigate ruminal acidosis, improve immune response and gut health, increase productivity (growth and milk production), and reduce methane emissions or fecal shedding of pathogens. More research is needed to explore the mode of action of specific DFMs in the gut of ruminants, and the optimal supplementation strategies to promote the development and efficiency of DFM products for ruminants.

Highlights

With the increased demand for animal products and the public’s concerns on the negative consequences of the livestock production, the industry has faced the pressure to improve animal production and health, reduce the negative environmental impact, and enhance animal products’ safety
The research on direct-fed microbials (DFMs) in ruminants is not as extensive as in the monogastric animals, with the majority focused on the impact of DFM supplementation on the rumen fermentation and production performance [19, 20] but fewer have been conducted to evaluate their effects on the lower gastrointestinal tract (GIT)
As dairy ruminants are at high risk of natural immunosuppression during transition period due to high energy requirement but low dry matter intake (DMI), further research is needed to understand the mechanism under the enhancement of energy supply and the suppression on pro-inflammatory gene expression in the gut or mammary gland in lactating ruminants supplemented with yeast DFMs

Summary

Introduction

With the increased demand for animal products and the public’s concerns on the negative consequences of the livestock production, the industry has faced the pressure to improve animal production and health, reduce the negative environmental impact, and enhance animal products’ safety. Effect of DFMs on ruminant health and performance DFMs have been considered as potential alternatives to antibiotics for neonatal and young ruminants, transition and lactating dairy cows, receiving and feedlot beef cattle, and small ruminants for the purpose to improve animal health, daily gain, milk production, and/or feed efficiency.

Results

Conclusion