Measurement of dairy cows‘ individual methane production rates : the Cubicle Hood Sampler, an on-barn alternative

Summary

Over the past decades, the potent greenhouse gases emissions from cattle farming have kept rising, and alleviating the impact of the sector on the environment has become undeniably crucial. Whilst animal geneticists and nutritionist actively work on discovering lineages and rations that will allow to lower enteric methane emissions, the evaluation of the performance of these measures remains limited by the available assessment methods. Several devices have already been developed in an attempt to quantifying the individual methane production levels from dairy cows under barn conditions, but they often appear to be either inaccurate, laborious or expensive. This study presents a renewed design of the Cubicle Hood Sampler (CHS) and the specifics of applied sensors. Featuring an extraction hood placed over the cubicles of the barn, the CHS offers the ability to collect and analyse, in a non-intrusive manner, the methane content of exhaled air and belching from individual cows. In addition, this system can collect samples over long periods of time, corresponding to the ten to twelve hours cows spend in the cubicles each day. It offers the possibility of overcoming the limitations encountered by most of the other devices regarding the insufficiency of sampling time. In the renewed design additional (RFID) sensors for individual cow recognition permitted the assimilation of each methane assessment to a specific cow, information that is necessary for individual assessments. Ultrasonic sensors monitored cows’ head positioning to filter out biased estimates of methane production rates that were linked to specific cow postures. However, the sensor modules need to be further improved to cope with barn conditions.