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domingo, 15 de dezembro de 2013

How do cows pollute?

Arthur Moniz. São Miguel, Azores

My students in year 10 have started studying food. For some reason, they found strange the link between cows and pollution. That was my motivation to write about this topic, although I am certainly not an expert and far from being vegetarian!

Cows emit a huge amount of methane (a colourless, odourless gas that affects the degradation of the ozone layer) through belching, and also a bit through flatulence. Statistics vary regarding how much methane the average dairy cow expels, but it is an amount comparable to the pollution produced by a car in a day.

To understand why cows produce methane, it's important to know they have a stomach with four compartments and digest their food in their stomachs instead of in their intestines, as humans do: they swallow their food and bring the cud back to their mouth to chew and eat it again, as they belong to a class of animals called ruminants. Their stomachs are filled with bacteria that aid in digestion, but also produce methane.

Some people justify their vegetarianism on the basis of meat being wasteful, such as using up a lot of water and creating a lot of greenhouse gases.

The romantic image people have of green pastures filled with fat happy cows as we can find in the Azores is actually a distortion of the reality.

 Most meat we eat comes from cows living in large feedlots without enough space to move. The main objective of meat production under those conditions is to make cows grow faster, by feeding them with hormones as well as antibiotics so that they can survive the unsanitary living conditions. The cows live there for only a few months before they are moved for slaughter.

So, before we taste beef, it is perhaps important to reflect upon what we are eating, such as its impact on global warming, as well as the conditions with which cows live. 




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