Losing animals can be tough. Yesterday one of my pigs pulled a chicken through the fence and killed it. Chickens don't usually fit through the fence (sometimes they go over it) but apparently a pig knows how to manage it in a second. The chicken was a notorious little fella always trying to steal the pig's treats though the fence, even though he's got the same pasture on his side of the fence. Well, the pigs cashed him in and spent the morning eating him up. And that's how you turn stupid/bold chickens into tasty pork. The grass is NOT always greener after all.
I think Burra pretty much said all there is to say about it. It's animal food at best and plant fertilizer at least.
It's also best that the runt be gone before he has the chance to pass on his weak genetics if you decide to let them breed. Though, after spending five months feeding and caring for him, I'm sure it's a little sad to not be able to consume him. It sometimes feels like a waste. Find a good use for him and you'll return his nutrients to your property to "try again".
When my kids drop food on the floor we call it an "upgrade" because we feed it to the chickens or pigs and get it back as eggs, chicken or pork.