Dr. Kris Johnson, the scientist most responsible for developing the methodology to use SF6 as an internal tracer to measure CH4 from ruminants, has been using a self‐contained, solar powered trailer‐mounted GreenFeed unit since June of 2011. In 2011, Dr. Johnson also conducted trials to compare the results of GreenFeed measurements with those of SF6 measurements for Angus cows on pasture. As the picture from early January of 2013 at WSU Dr. Johnson, along with Jennifer Michal, are measuring emissions from a group of growing angus beef heifers across a variety of different forages and pasture. Part of the research is to determine seasonal CH4 and CO2 emission changes from individual heifers for different management strategies and over the growth and birthing cycle. Her team is also analyzing the stability of ranking among animals in the herd.
Michal, J.J., P, S.J. Krizsan, M. Hetta, H. Gidlund, E.H. Cabezas Garcia. 2013. Repeatability and between cow variability of enteric CH4 and total CO2 emissions. Adv. Anim. Biosci. 4:536. View Here
Zimmerman. S., J. J. Michal, R. White, K. A. Johnson, A. Guerouali, P. Zimmerman. 2013. Evaluation of a novel system to measure enteric methane emissions from beef cattle on pasture. J. Dairy Sci. 96(E-Suppl. 1):471. View Here