There was an interesting TV show on British TV (apologies, my Google foo is not able to find the name at this moment in time) where they invited a number of people to eat dishes at a hypothetical restaurant, after each course the tallied the carbon emissions released in creating the dish.

Now obviously being a TV show they had to show some extreme examples but it was definitely interesting when things like imported asparagus dishes released more than the British beef dish. However, things like the wine were even more challenging, wine imported from Australia in bulk tanks was relatively ok, but wines imported after bottling (from Europe for example) where horrible because of the extra transportation.

The "from cows" technically makes it pretty much true. Regardless, it's not a constructive comment for that reason.

Not all sources of food contribute equally to climate change. That is why this article is about cows, and why I commented about cows. They pollute the most.