I heard that more animals die with vegetarian diets than with meat diets.
It's because the amount of grains needed to supply someone with food is like 12 pounds or something but the equivalent to feed a cow would be 7 pounds of grains. However the amount of animals that dies in that extra 5 pounds of grains is a lot more compared with the 7 pounds plus the cow or whatever it is they kill. This is counting vermin, but I think people only care about the cute animals.
I haven't heard such bullshit for a while. It lacks any logic. Where did you read it?
Even people that really know nothing about nourishment should see, that huge amounts of energy are needed for organical transitions.
If you feed a cow only on grain it dies after two days,
but for increasing the overall weight for 1kg per day calfs get a power diet of
2kg each day containing
Oats 14%
Barley 14%
Linseed cake 12%
Molasses 5%
Extraction meal (soy or canola) 16%
Dried beet pulp (sugar beet) 20%
Mineral feed / vitamins 4%
If you want to directly translate the energy needed for 1kg beef in grain anyway, you end up at 16kg.
You could feed lots of humans with that.