Variability in Enteric Methane Emissions among Dairy Cows during Lactation.

The aim of this study was to investigate variability in enteric CH emission rate and emissions per unit of milk across lactations among dairy cows on commercial farms in the UK. A total of 105,701 CH spot measurements were obtained from 2206 mostly Holstein-Friesian cows on 18 dairy farms using robotic milking stations. Eleven farms fed a partial mixed ration (PMR) and 7 farms fed a PMR with grazing.

Detection of Methane Eructation Peaks in Dairy Cows at a Robotic Milking Station Using Signal Processing.

The aim of this study was to investigate the use of signal processing to detect eructation peaks in CH released by cows during robotic milking, and to compare recordings from three gas analysers (Guardian SP and NG, and IRMAX) differing in volume of air sampled and response time. To allow comparison of gas analysers using the signal processing approach, CH in air (parts per million) was measured by each analyser at the same time and continuously every second from the feed bin of a robotic milking station. Peak analysis software was used to extract maximum CH amplitude (ppm) from the concentration signal during each milking.