Interpretive Summary: Cecal microbiota of feedlot cattle fed a four-species Bacillus supplement

By: Luke K Fuerniss, Kelly K Kreikemeier, Lynn D Reed, Matt D Cravey, Bradley J Johnson

Microbes in the rumen break down fiber and complex nutrients into energy that cattle can absorb. Rumen microbes are becoming well studied, but the microbes of the hindgut—specifically of the cecum and large intestine—are less well-studied. As feedlot cattle eat large amounts of grain, maintaining health and balance of microbes in the hindgut is important. Overconsumption of a meal causes a greater proportion of digestion to occur in the hindgut, causing greater acid production that damages the gastrointestinal lining. If dietary microbial supplements support a more diverse microbial population, the challenges caused by greater hindgut digestion could be mitigated. To test this, cecal microbes were characterized after feedlot cattle were fed a conventional diet, with or without a supplement of Bacillus bacteria. Cecal samples from cattle that were fed Bacillus had greater microbial diversity. Approximately half of the cecal samples from cattle that were not fed Bacillushad disrupted microbial balance. Based on taxonomic assignment, bacteria observed in these disrupted samples indicated greater energy density of digesta and increased methane production. Supplementing feedlot cattle with Bacilluscould improve hindgut microbial diversity.

Read the full article in the Journal of Animal Science.