Alternative methods of selenium (Se) supplementation have been evaluated in Merino sheep grazing irrigated pasture at Tara Hills Research Station near Omarama. Unsupplemented ewes and lambs were extremely Se deficient and production losses were high. Barium selenate (DeposeI@) injections, intraruminal Se pellets (Permasele) or the strategic grazing of recently Se-topdressed (Selcotee) pasture for at least one month pre-joining all gave a rapid and large rise in the Se status of ewes and met ewe requirements for 12 months. The barium selenate and intra-ruminal pellet treatments allowed a substantial transfer of Se to lambs at birth, and lambs would not require further Se supplementation until after weaning. With strategic grazing and oral treatments it is necessary to provide lambs with supplementary Se as early as possible. A single application of Selcote Ultra* prills at 1 kg/ha was effective in supplying adequate Se to Merino wethers for 24 months. Deposel, infertility, liveweight, Permasel, Selcote, Selcote Ultra, selenium, sheep, white muscle disease, wool
