A mixture of potassium sorbate and sodium benzoate improved fermentation quality of whole-plant corn silage by shifting bacterial communities.

Abstract

To investigate the changes in fermentation quality of whole-plant corn silage ensiled with varying dosages of mixed organic acid salts (MS), and link these dosage changes to shifts in bacterial composition. Fermentation quality and bacterial community of corn silage ensiled with MS at four application rates (0, 0·67gkg-1 , 1·33gkg-1 , and 2·00gkg-1 ) were investigated. The MS consisted of 40% potassium sorbate and 60% sodium benzoate. The corn silages were conserved for 42days. Dry matter losses and ammonia nitrogen concentration were linearly declined by up to 19·10 and 33·3% with increasing dosages of MS. MS treatments significantly reduced the pH of silage vs the control group. Further analysis indicated that the improvement of fermentation quality was the result of shifts in bacterial composition, the relative abundance of Lactobacillus paralimentarius and Pediococcus spp. increased while Lactobacillus reuteri, Lactobacillus coryniformis and Klebsiella declined with increasing dosages of MS. MS effectively improved the fermentation quality of whole-plant corn silage with an optimum dosage of 2·00gkg-1 . The correlation between bacterial taxa and fermentation quality provides a potential for the development of novel silage inoculants and for the application of MS on controlling Klebsiella mastitis of livestock farms.