Measurements of methane made using the Laser methane detector are related to total daily methane output in beef cattle

ROOKE J; RICCI P; DUTHIE C-A; ROEHE R; WATERHOUSE A

Saint-Malo

Simposio; International Symposium on Emissions of Gas and Dust from Livestock; 2013

International Symposium on Emissions of Gas and Dust from Livestock

In this experiment, using beef cattle, methane (CH4) measured using the laser methane detector (LMD) was compared with daily CH4 output measured using respiration chambers. Daily CH4 outputs were measured from 68 cross-bred steers fed total mixed rations consisting of either 75:25 or 8:92 forage:concentrate (DM basis).  LMD measurements were recorded independently from each steer between 09.00 and 10.00 h on each of 3 consecutive days; measurements were made every 0.5 sec during a 4 min period. The CH4 recorded by the LMD consisted of a regular series of small respiratory peaks and larger irregular peaks representing CH4 eructation. Daily CH4 production (g/day, measured in respiration chambers) and CH4 (ppm.metre) by LMD were both significantly (P< 0.001) lower when the high concentrate diet was fed.  Significant correlations were observed between LMD CH4 concentration and CH4 output (g/day) measured in chambers (P< 0.001). Overall, CH4 concentrations quantified with LMD were in agreement with CH4 outputs from respiration chambers.  Further validation of the LMD is needed to be able to quantify CH4 emissions from animals under diverse management situations.