Observations on the response of Merino weaners to a fodder supplement, a feeding block, and cobalt and selenium treatments

Abstract

Summary-The response to supplementary feeding of weaners was studied at Condobolin, New South Wales. Three equal groups of 120, 3-4-month-old Merino weaners were rotated every six weeks for 18 weeks in a three-paddock system. The pasture consisted mainly of relatively dry heliotrope (Heliotropitlm europaetm) but there was some green fodder provided by other pasture species. Unsupplemented weaners gained 54 g per day and a group supplemented with unrestricted amounts of a hammerrnilled mixture of three parts chopped lucerne hay and one part oat grain gained an additional 7 g per day (P<0.05). The mean greasy fleece growth of the supplemented group (2.86 kg) between birth and approximately 10 months of age was greater than the unsupplemented group (2.68 kg, P*lt;0.05). The cost of the supplement would appear to be greater than the increased returns. Weaners allowed unrestricted access to a mineral feeding block gained a mean weight of 42 g per day which was significantly less than the unsupplemented group (P<0.05) and failed to maintain weight during the last six weeks of the trial. Selenium and cobalt treatments, which were given to some sheep in all groups, did not affect body weight gain or wool production.