The use illumina sequencing technique in studying rumen bacteria diversity of Bali cattle given a feed comprised of elephant grass and rice straw

The diversity of rumen bacteria in ruminant animals is highly determined by various
factors, including the age and the breed of the animal as well as the feed consumed. The purpose
of this study was to evaluate the diversity of rumen bacteria of Bali cattle due to the provision
of ration consisted of rice straw and elephant grass as a basal diet. Three adult Bali cattle were
given a ration consisted of rice straw and elephant grass ad libitum for four weeks before taking
the rumen fluid samples. In addition to the basal diet, each animal was also given a concentrate
at the rate of 0.5% of the body weight. Rumen fluid samples were analyzed for pH, NH3 and
VFA, while the diversity of the rumen bacteria was determined by the Illumina Sequencing
technique. The results of the study showed that rumen conditions of the animal were ideal for
the growth of the rumen bacteria, indicated by the value of rumen pH, NH3, and VFA of 6.8,
156.7 mg/L, and 114.3 mmol/L, respectively. Furthermore, based on SILVA taxonomy, two
dominant phyla, i.e., Bacteroidetes and Firmicutes, were successfully identified in this study. At
the genera level, the most dominant group identified was Prevotella 1, followed by the
Christencenellaceae R-7 group. The analysis also showed the existence of an uncultured rumen
bacterium with a percentage of 6.98%. In conclusion, the feed provided for the animal was good
enough to support the growth of rumen bacteria and the Illumina sequencing technique used in
this particular study was able to identify the existence of dominant rumen bacteria as well as the
uncultured rumen bacterial of Bali cattle under such feeding conditions