A cow is essentially a machine that turns inedible food into nutritious edible food.
However, we(humans) as we always do, took things too far, and have been turning lots of wild land to make grass as food for these cows that eventually turn them into proteins. That only leads to more and more grass production and burping cows :-(
This is not the reference, but something I just found on google books about the efficiency of dairy cows: https://www.google.com/books/edition/Farming_the_Business_Ma...
(responding to request for the reference for the dairy cow as an efficient converter of grass on rocky hillsides).
According to this article it takes 1847 gallons of water to make 1 lb of beef and 122 to make one gallon of milk, compared to 39 for 1 lb of vegetables:
https://www.denverwater.org/tap/whats-the-beef-with-water
Admittedly, that water doesn't disappear and stays in the water cycle, but every lb of beef that is reduced from the diet saves enough water to supply a household of 4 for almost a week (assuming 80 gallons per person/day)
With the droughts due to climate change interfering with the water cycle and changing the actual local climates of farming areas, without change happening it may become a requirement to drastically reduce the amount of beef that we consume in order to have enough water to survive.
Either that or we will need to start catching rain as it falls on the ocean and shipping it in to make up for the overuse.
I'm beginning to think ruminants are often shown in a poor light by common statistics. And not due to deceit, just reliance of simplistic statistics that do not tell the whole story.
Take the graph showing a cow requires 31.7kgs of food to produce 1kg of meat. But this can be (but sometimes not) all grass which is indigestible to all the other animals here. Pigs and Chickens are at 10.2kg feed/kg meat and 4.2kg feed/kg meat, but this is generally all food which is digestible by humans. Fish are at 2.3kg feed/kg meat, but the fish humans eat almost all naturally eat animals for feed.
Another graph in this shows that maybe 60% of land in the US is used for grazing. This doesn't mean that this land could be used for growing crops. Often ruminants are grazing on marginal land that isn't good for growing other foods.
Similarly methane from ruminants digestion is considered the same as methane from a gas wells for most climate change modelling. But it seems to me that over the 20 year lifetime of methane in the atmosphere, a fixed heard of ruminants would have a fixed amount of methane in the atmosphere. While methane from fossil fuels is more carbon put back into the carbon cycle just seems objectively much more damaging.
Also a smaller portion of their feed ruminants consume would naturally turn into methane if it hadn't been eaten by farmed ruminants.
I've cut back on the amount of red meat that I am eating, but I still think that a more holistic look at ruminants would probably have them looking better than some simple statistics make them look.
My bias is that I grew up on a farm. I am fond of cows and sheep and I would be sad if they went away. I want them treated well, but don't mind them being slaughtered for food.