Methane Emissions and Feed Additives

At Pennsylvania State University (PSU), Dr Alexander Hristov collaborated with C‐Lock to develop the first GreenFeed system mounted on a cart to make measurements of CH4 and CO2 fluxes for dairy cattle in tie‐stall dairy barns.

Dr. Hristov’s research has focused on the development of natural plant materials and extracts that can be added to cattle feed to reduce CH4 production and increase feed inefficiencies. His GreenFeed unit is equipped with a UPS system and a Conditional Sampling System.

To sample CH4 emissions from the animals in tie-stalls the GreenFeed unit is wheeled in front of each animal which is tied‐up in the stall. GreenFeed then delivers a small amount of feed over time so that CH4 and CO2 emissions are measured for 5‐7 minutes. GreenFeed is then wheeled to the next animal for sampling. The process is repeated four to five times daily for each animal over a period of a few days to accumulate high‐precision emissions data. Methane emissions resulting from CH4 inhibitors have been measured from lactating animals over long time periods.


Branco, A. F., F. Giallongo, T. Frederick, H. Weeks, J. Oh, and A. N. Hristov. 2015. Effect of technical cashew nut shell liquid on rumen methane production and lactation    performance of dairy cows. J. Dairy Sci. (accepted).

Branco, A. F., F. Gaillong, T. Frederick, H. Weeeks, J. Oh, A.N. Hristov. 2014. Effect of Cashew Nut Shell Liquid on Lactation Performance and Rumen Methane Production in Dairy Cows. J. Dairy Sci. 97 (E-Suppl): 854. View here