We've been thinking about breeding season since lambing season. In fact, during lambing season we were thinking about breeding season. We marked twin and triplet born ewe lambs (they're ear notched when we ear tag) and marked (with SI-RO-MARK or Sprayline) which ram lambs to keep intact.
We're planning to breed 475 ewes this season. Rams went in May 1st with a select group of hair cross ewes. The remaining ewes will be bred in groups with plans to have breeding finished by Mid October (we're shooting to have our last lambing day on March 15th. To keep track of who has been bred and who hasn't we're using marking harnesses and raddle marker. Not exactly sure which as the farm guys haven't put the rams in with the ewes.
Yellow and blue were the least readable a week after marking (by hand, not by a ram). Test was at Premier in SE Iowa in July. Purple, green, red and orange were the most readable colors.
Purple and red were the most readable. Green, blue and orange less so. Yellow the least (but still readable).