What goes in, must come out? The trouble is that with cows the grazing process has an effect on the environment, some would say. Is recycling possible? What are the facts?
Research in California has branded cows an environmental threat. Measurements showed that a dairy cow produces 9 kilograms of smog-forming gases every year. I don’t want to think about how they measured that, but apparently the volatile organic compounds (VOCs) that each cow emits exceed those of a car. American cars are BIG, so in the UK we might be looking at 1 cow = 2 average cars. There has been a lot of progress in reducing vehicle emissions, but catalytic converters for cows are some way off yet.
The more solid compounds that herds produce are already recycled – either straight on to the land, or into slurry pits for spreading later. That’s one problem dealt with, though if you live in a village next to a slurry lagoon then it can still be a problem. There are suggestions that the concentration of nitrates in the slurry results in groundwater pollution, though it is hard to separate this out from regular fertilizer run-off. Either way, the farmers get blamed.
Just digressing for a moment, the drive for ever cheaper food has led to industrialized farming for sure, but the waste problem goes beyond that. Cheap, industrially-produced food has necessitated packaging for preservation, and that pushed up the use of plastics (which in turn are largely oil-based). Bio-based (so-called green) plastics have become more common, but even these have a negative environmental impact, needing energy, land area and fertilizers to grow the bio-base. Either way, the drive for cheap food has compounded the waste problems Western society faces today.
Rant over, back to the herd. Now, the VOCs that the cow produces are mainly combustible methane, and that could be used for heating and cooking, or power generation. Methane is a potent greenhouse gas, and atmospheric levels have almost trebled since the 18th Century – and cows are not all to blame – it comes from landfill waste sites, too. In nature, it comes from marshes and wetlands (‘marsh gas’), and also from natural gas leakage from underground. Human beings produce it, too, so don’t blame the poor cows.
The problem would be in collecting it from cows, but there may be a way in the future. The key to it is the fact that it is lighter than air (that’s why it is a greenhouse gas – it rises in the atmosphere). Here’s the idea:
A bold English farmer has set up a ‘zero grazing’ farming operation, with almost 600 cows kept under cover. The idea was pioneered in mainland Europe. It is not anything like factory farming – these cows are kept in a large open enclosure with a concrete floor, which has a glazed roof over it. The cows do not graze – they are fed with a proprietary feed. By all measurements of animal stress, they are ‘chilled out’, to quote the farmer. On the plus side, their milk is of a higher and more consistent quality as the feeding is not subject to variable grazing quality. The herd is also healthier. Certainly, there is agriculture involved in production of the bulk feed, but nothing is perfect (it takes 33,000 cubic feet of natural gas – mostly methane – to make 1 ton of nitrogen-based fertilizer for crops).
So, what about the methane? Well, with 600 cows under a roof, it cannot be beyond the wit of man to devise an arched roofing structure with extraction ducts? Let’s do some sums: 600 cows produce over 5 tonnes of methane a year. My rough calculations put this at about 250 million BTU. In simple terms, enough energy to power an average home (UK) for about 2 months.
I guess the next step would be to reduce it to cows per cup of tea, but my head is hurting after all those calculations! In summary, it is true what they say about cows, but the cows are only part of the problem. What about all the other farm animals? It just serves to highlight the ways in which society and nature is interwoven, and how answers to environmental problems are not always clear-cut.

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