Quality and microbial community analysis of solid-state fermented feed with mixed bacteria from corn silage.

Abstract

The efficacy of microbial fermented feeds (FF) is highly dependent on microbial composition, underscoring the need for locally sourced, cost-effective formulations to advance sustainable livestock production. In this study, bacteria from corn silage (CSB) were screened for the preparation of solid-state fermented feed (SFF). In addition, for the purpose of comparison, purchased marketed fermentation bacteria (PMB) for SFF were also tested using the same methodology. Anaerobic fermentation was carried out by adding 5% CSB, PMB, and saline to conventional feeds at 37 °C, respectively. Then 10 g of fermentation samples was collected on days 0, 3, and 5, respectively. The composition and diversity of the microbial community were subsequently analyzed using high-throughput sequencing. The pH, titratable acidity (TA), and nutrient index of the feeds before and after fermentation were determined. High-throughput sequencing results showed that the dominant genera of CSB were Weissella, Pseudomonas, and Bacteroidetes, whereas the dominant genera of PMB were Bacteroidetes, Bacillus, Pseudomonas, and Enterococcus. The dominant genera in unfermented feeds (CK) were Chlorophyta, Mitochondria, and Pseudomonas. In addition, the dominant genera in SFF supplemented with CSB and PMB were Weissella and Bacteroidetes, respectively. Compared with CK, pH of SFF supplemented with CSB and PMB decreased gradually, and TA increased significantly and then decreased gradually during fermentation. Similarly, Crude fiber content was higher than CK in both CSB and PMB, while crude fat content was lower than CK for all of them. The study illustrates that CSB can be used to ferment porcine solid feeds and that CSB solid feed microorganisms may promote intestinal absorption of complex polysaccharides in pigs, which lays a certain theoretical foundation for the application of CSB to SFF.