On the use of a laser methane detector in dairy cows

In the present study, the ability of a recently developed, proprietary, laser methane detector (LMD) to estimate enteric methane output in dairy cows without any disturbance to the normal activity of the cows was examined. Measurements were taken on Holstein Friesian cows, which were on a long-term 2 × 2 factorial, genotype × feeding regime (management system) project based at the SAC Dairy Research Centre, Dumfries, Scotland. Of all the systematic factors that were tested in an analysis of variance, only cow activity (p < 0.001) and lactation status (p < 0.05) had significant effect on the enteric methane measurements. Ruminating cows had 1.4 and 1.1 times higher LMD values than idle and feeding cows, respectively. The enteric methane measurements in the current study were not affected by the operator meaning that the hand-held methane detector could be operated by different operator without affecting the measurements. The study has demonstrated that the use of the LMD is feasible in dairy cows and the data produced make biological sense. However, further studies are required to explore other aspects of the data.