oat silage ensiled at different temperatures
The low temperature during oat harvesting season in Qinghai-Tibet Plateau pose a significant challenge for successful fermentation. Psychrophilic lactic acid bacteria (LAB) have been verified as a feasible method to improve the silage quality of alpine regions. However, there is still uncertainty surrounding the effects of psychrophilic LAB with exopolysaccharides (EPS)-producing property on silage quality. EPS is a typical metabolite produced by LAB to thrive in extreme environments, possessing antimicrobial, antioxidant, and immunomodulatory activities. Therefore, this study aimed to investigate the effectiveness of psychrophilic Lactiplantibacillus plantarum L75, which produces EPS, on the characteristics of oat silage and its antioxidant capabilities at low temperatures. L75 demonstrated superior EPS-producing characteristics, growth performance, and acid production compared to MTD/1 at all temperatures. Both L. plantarum L75 and MTD/1 inoculation resulted better fermentation quality and reduced undesirable microorganisms such as Hafnia alvei and Ewingella americana throughout the fermentation process. L75 was more effective than MTD/1 in enhancing fermentation quality, antioxidant activity, and increasing the proportion of Lactiplantibacillus in oat silages. Additionally, L75 minimized dry matter loss and the production of ethanol and ammonia nitrogen, consequently preserving more nutrients at low temperatures compared to MTD/1. In brief, temperature played a significant role in oat fermentation particularly in the alpine regions of Qinghai-Tibet Plateau. The application of L75 has shown promising potential in this regard.