...or indeed, any sentient being).
I ask these questions as a vegetarian of long-standing.
Rats are sentient and there are more rats on this planet than humans, should we be eating them as a method of control and also in order to reduce the developed world's insatiable appetite for industrially produced meat and, at the same time, provide a valuable protein source for folk in the under-developed nations? What about locusts or anything destructive including deer and rabbits but not humans ?!?!?!
Guinea Pigs are a food staple in South America, particularly in the Andes where they originate, how come we in the West keep them as pets and think it's not OK to eat them?
Is it OK to run drug tests/trials on animals? If not, how are they to be tested before releasing them for human use? Maybe we should run the tests only on the people on Death Rows around the world? If they complete 5 years of trials without it killing them, they get a pardon and are released back into society???
Where is the line in the sand that says this "thing" that breathes is sentient and this one is not?
I wish this (ab)use of animals question had an equitable answer but, in my opinion, it never will have because even if the world eats laboratory grown meat what will we do with the few animals of all species that will be kept in zoos, private collections and in the wild. They will need to be husbanded to make sure they don't die out or outgrow their allotted space. What will we do with them when they are too old to be self-sustaining and what do we do with the animals that need to be culled because there are too many of them. Will they all be sold for consumption in specialist restaurants to the rich and the famous who will, arguably, be the only ones to afford such exotic fare?
Whatever the "solution", sentient animals will have to be killed and we will certainly not just compost them, not when there is money to be made - even if the money goes back into a fund to maintain that status quo.