There have been experiments in methane collection from cows using various types of bags, but the two most effective means of collection are diet and waste collection. The first is the heavily grain fed way most cows are fed. A lot of the grains cows are given aren't part of their natural diet causing the microbial activity in their stomachs to produce more methane than the more basic grass and hay fed cows. As for waste collection, as long as most of the waste is allowed to collect outdoors in uncovered areas a tremendous amount of the methane is wastefully created and emitted into the environment. This isn't a problem for free range cattle since their manure acts as fertilizer, but for industrial farms this is a big problem. By pushing this waste into covered specialized spaces, the methane produced by this aggregated waste can be collected and actually used to generate electricity. There have been several successful experiments demonstrating the viability of this approach.

The residual which is provided by the cow is highly organic. This material is dumped in a large tank and it is mixed with water to form slurry. This slurry is covered for around 15 days. Bacterial action takes place inside the tank and this whole setup is known as Biogas plant. You can add dead plants to make it more effective. This plant has an inlet pipe through which we can add more slurry and the outlet pipe through which the methane gas is produced.

On-farm methane digesters are available for collecting methane from the manure of cows and burning it to generate electricity. A part from it, scientists has designed methane-powered refrigeration system in which methane can be used to heat water or to cool the milk. In both cases, one big size tank is required for collecting & storing dairy effluent.