August 15, 2018

Interpretive Summary: Effect of engineered biocarbon on rumen fermentation, microbial protein synthesis, and methane production in an artificial rumen (RUSITEC) fed a high forage diet.

Interpretive Summary: Effect of engineered biocarbon on rumen fermentation, microbial protein synthesis, and methane production in an artificial rumen (RUSITEC) fed a high forage diet.

By: Surely Wallace

In an article published in August 2018 in the Journal of Animal Science, researchers studied how biocarbon affected rumen fermentation in an in vitro setting using the RUSITEC artificial rumen.

Methane gas is a waste product of bacterial fermentation in the rumen. Considering the greenhouse effects of methane on climate, there is need to investigate ways to curb emissions in cattle by altering feed. Biocarbon, also known as biochar, is an engineered feed additive that may be effective at reducing methane production in rumen. Therefore, the authors chose to study biocarbon’s effects on rumen fermentation in the RUSITEC artificial rumen.

The study design was as follows: 0.5, 1.0 and 2.0% biocarbon by dry matter (DM) were added to barley-based basal diets; an additional control diet had no biocarbon. Each treatment had four replicates. Rumen contents from cannula port of Angus cross cows were collected after morning feeding. The study lasted 17 days, and samples were collected and analyzed after day 10. 

Results indicated total gas did not decrease, but total methane produced did decrease, compared to control. When compared to the control, total microbial nitrogen and total microbial protein synthesis was also increased. Nutrient digestibility was improved, per increases in DM, organic matter (OM), crude protein (CP), and fiber disappearance.

In conclusion, changes in rumen fermentation were observed in the RUSITEC in vitro apparatus, with the authors reporting a benefit, supported by their data. Specifically, biocarbon appeared to increase feed digestibility and reduce production of methane gas. It is possible that changes to the rumen microbiota from biocarbon may have caused this effect. However, the study did not focus on rumen microbes, so this is only one possible explanation. The authors suggest it is possible that the biocarbon may be sequestering methane. More in-depth studies characterizing the mechanistic factors that might be contributing to reduction in rumen methane production in biocarbon-supplemented cattle feed is warranted.

To view the article, “Effect of engineered biocarbon on rumen fermentation, microbial protein synthesis, and methane production in an artificial rumen (RUSITEC) fed a high forage diet,” visit the Journal of Animal Science.