Leppi if your question is simply 'Was Bentham a vegetarian ?' the answer is that not even the International Vegetarian Union claims him as one, though perhaps they'd liked him to have eaten no meat. They give his name with '(??)' after it to indicate that he may have been one but they don't know

(source: their website under their list of famous vegetarians).
You may be concerned with a wider question, though.
Here's a quote from his 'Introduction to the Principles of Morals and Legislation' [ You may find the original;I've had to retranslate it from a French website; you can guess , from the opening words, why they chose it

)]:
" The French have already realised that a dark skin is no reason to abandon, without remedy, a human being to the whims of his persecutor.Perhaps one day we'll end up by appreciating that the number of legs, the furriness of the skin or the tip of the sacral bone are completely inadequate reasons for abandoning a sensate animal.
The question is not 'Can they reason?' nor 'Can they speak ?' but 'Can they suffer ?' "
This question ' So, do you think animals have rights?' is a favourite one, of many surprises, to spring on would-be students at Cambridge University in their first interview. It is preceded by the disarming,chatty, innocuous and amicable 'I see/hear you ride horses/keep pets' or whatever reference they can find or get out about animals and the candidate. Whatever the answer they'll have a good follow up line. (So, Leppi, apply now; you may be one up on the others!

)
You may think that it's not a question of animals having rights but of humans having duties.Some vegetarians would have us believe that raising animals to kill for food is immoral.Humankind has done more than just raise. It has selectively bred animals for the sole purpose of eating them, sometimes with bizarre results; the Christmas or Thanksgiving turkey is not just far removed from its ancestors but is far removed from other birds. The male bird is so enormous and unnaturally shaped that he cannot, normally, mate naturally and so the birds are bred by artificial insemination. What interference with his or the species' rights is that?
The sustainable argument, which Bentham certainly approved of, was no more than that we had a duty not to cause suffering to animals. The fact is that the stun gun used to kill those pigs, cows and bullocks that we bred, fed and cared for causes instantaneous death. That kiling is humane and morally justified. The same cannot be said of force feeding geese so that their livers are distorted and enlarged to make foie gras or keeping veal calves in low light and in narrow cages (so they cannot move about) just to ensure that the meat is tender and white. And if you are wondering about other European 'traditions' this particular English farm owner thinks hunting foxes with hounds is a barbaric cruelty as well.
I don't suppose that Bentham opposed the death penalty, though I stand to be corrected by you or others (you'd best check

). His concern would be, as with the black people and the French, that the condemned man should not suffer cruelty and , for example, execution by decapitation in France was not cruelly causing suffering. He would condemn, though, torturing people or inflicting physical hurt whimsically whatever the supposed reason, if any.