I hire out registered Southdown tups for four weeks at a time, once only per season. Our flock has high health status (no scab, orf, toxo, Johnes, Jaagsiekte, etc.) and all are wormed, foot checked and quarantined for at least six weeks upon return. I mostly hire unrelated tups to folks who've purchased ewe lambs from me in the past. I've never had any problems with the tups upon return and they've always got all their girls pregnant in the four week hire period. It's getting a bit late for tupping in this area, tups are in now for an Easter lambing.