The present invention generally relates to a method for reducing the production of methane emanating from the digestion of animal by using one or more essential oil compounds selected from the group consisting of limonene, eugenol, a silicylate, quinoline, vanilla, thymol and a cresol, which are administered to the animal feed. In operating a flowmeter, it may be the case that, if not properly calibrated, the flowmeter will produce erroneous measurements, e. The context object includes methods for recording within the context object a set of properties identifying the client. This solution is then drawn back up from the enclosed volume wherefrom a sample of the solution can be taken. The two computing module portions of the data center module may combine to form a computing space when coupled to one another. The backrest structure includes a backrest-adjusting device to provide the linkage movement and also offer multiple stage adjustment of the backrest angle.