Short Communication
Muhammad Wasim Iqbal, Qin Zhan
Abstract
Oven dried cassava residues, corn straw silage, elephant grass and sugarcane tail silage were used as substrates to do a 24 h of incubation with a 100 ml glass syringe at 39°C. Gas production was recorded at the end of incubation and ruminal fluid was harvested to determine volatile fatty acids (VFA) using gas chromatograph, quantify microbial populations using real time PCR, and analyze microbial community using high throughput sequencing. Results showed in vitro incubation not only decreased population of bacteria, fungi, methanogen and some cellulolytic bacteria (P<0.05), but also increased diversity of bacteria, reversed Firmicutes to Bacteroidetes ratio, and decreased abundance of Prevotella, M. gottschalkii and Entodinium. Gas production, acetate/propionate ratio and abundances of Succiniclasticum, Entodinium and Diploplastron were the highest, while total VFA concentration, fungal and cellulolytic bacterial populations, and abundances of Methanomassiliicoccales and Ostracodinium were the lowest with cassava residues (P<0.05). Influence on fermentation pattern and microbiota of three gramineous substrates was similar, but inoculum incubated with sugarcane tail silage had higher abundance of Methanomassiliicoccales and Diplodinium. In conclusion, cassava residues which is a low neutral detergent fiber forage showed a completely different fermentation pattern and influence on microbe community indicated NDF was the most crucial factor to determine microbial community in vitro.