Silage pathogens and biological control agents: effects, action mechanisms, challenges and prospects.

Silage is a high quality, nutritionally rich animal feed with high palatability and is usually produced by the fermentation of beneficial microorganisms, mainly lactic acid bacteria (LAB), under anaerobic conditions. However, the fermentation process is jeopardized by pathogenic microorganisms, including yeasts, molds, Clostridia, Listeria sp., Escherichia coli, etc., that can grow and proliferate during the ensiling process, leading to spoilage and degradation of the silage quality, thereby affecting animal productivity and health. The use of biological control agents (BCAs) has been suggested as an alternate strategy to chemical additives for inhibiting silage pathogens due to their safety as naturally occurring microorganisms that can inhibit the growth and activity of pathogens through various mechanisms during silage production. This review highlights silage microorganisms and silage pathogens and discusses the main BCAs, such as LAB, certain fungi and plants, and their metabolites, as well as their mechanism of action in the control of silage pathogens. In addition, the roadmap for efficient management of silage pathogens by BCAs was proposed, which entails sophisticated screening methods and the application of modern biotechnology techniques (MBTs) that are pertinent in unveiling the relevant prospects for enhancing the stability and effectiveness of BCAs against silage pathogens. [ABSTRACT FROM AUTHOR]