It depends on your moral values which can be different.
If you skip the simplification vegans are using to justify eating plants (they don't scream and run away when we're trying to eat them) you hardly can eat anything ethically.
If you skip the simplification vegans are using to justify eating plants (they don't scream and run away when we're trying to eat them) you hardly can eat anything ethically.
>> Plants lack nerves or a central nervous system or the ability to directly react to their circumstances
Is the same as:
>> they don't scream and run away when we're trying to eat them
A pasture-fed cow kills approximately zero of the same.
Assuming your ethics give equal treatment to all mammals, the rural hobby farmer comes out far, far ahead of the urban vegan.
Sure, if we all had a cow and two acres and lived in a temperature environment where the animals could graze all year, we could have milk after the cow has had a calf. But who impregnated her? And what are you doing with the calf because it needs two acres of grazing pasture too. And then who impregnates her next year and what do you do with that calf? Another two acres? What about the harsh winter or summer? You're going to need to supplement with extra hay. Off to the agricultural supply who... ah crap, they farm. Farming kills fuzzy animals! Now we're terrible again!
Cows, like all mammals, aren't unending milk supply systems. They dry up because they lactate for a reason. Your imaginary hobby farm is an unsustainable system.
Source: I have a grazing pasture and grazing animals.