I don't know if it's better to use them or just castrate the lamb when it's tailed. I think I prefer the little green bands, the nuts just drop off but there's still a common practice of knife castration when tailing the lambs. Actually having merinos in this country with the bloody flies is ridiculous. The farmers, graziers, pastoralists, they have to put a lot of work and resources into maintenance of the animals, particularly as they've been bred to develop larger folds than the original merinos from Spain and the Great Karoo so that they'd yield more wool. English breeds tend not to get flystrike so bad but merinos get it bloody awful if they haven't been mulesed or dipped on time.