I use ear tags. Don't you trust the abattoir? I ask, as the one I use was recommended to me by a young vet as they did her pigs. I went out to have a look at it and I couldn't find it, I had to ask a postman. When I did locate it, it was shut but they also have a shop so I went to the shop and me being me, asked them straight out, "How can I guarantee that I get back my own animal?" Lets just say it went quiet! Anyway, the reply come back, politely, "We have rules that we have to follow and have built up trust with our customers!" I've been using them since 2003! I do also use a smaller abattoir which is further away, but only because I have no cattle transport and the previous time I had beef done, they came and got it but couldn't this time, so I asked him, "Can you haul for me or do you want the job?" He did the job, 2 big whopping Angus's too! He did another heifer and lambs for me last year. Its very much trust. Put it this way, I can eat the meat, but I cannot kill and skin etc!