I would ring the pound. Most people think that it is just for dogs but rural pounds will callect pretty much any domestic animal - and then the owner will have to pay a fee to recover it and also have to pay for their feeding.

Maybe I am mean - but seriously - if you are hand feeding then there is no way I would be having any other animal eating my precious fodder. I am guessing that they are at your place because there is no feed at home - and by the sounds of it the owner doesn't really care - so I wouldn't sent them back there I would get the guy at the pound to sort it out.