Supplementation to improve the production of yearling steers grazing poor quality forage. 2. The effects of oats, supplementary nitrogen, lupins and cottonseed meal

Abstract

Four supplements were compared in an experiment in which yearling Hereford steers were grazed on mature annual pasture for 84 days and fed, at levels of 0, 300, 600 and 900 g/steer.day, supplements of pelleted cottonseed meal, lupins, oats + isobutylidene diurea (IBDU) or oats alone. The supplements increased growth rates from - 2 14 (no supplement) to 321, 119, 47 and 47 g/steer.day respectively (900 g/ steer.day). The cottonseed meal supplement produced significantly better growth rates than the other three supplements, the responses to which did not differ significantly. During a period of 111 days after supplementation, when all steers were lot-fed as one group prior to slaughter, there was substantial, but not complete compensatory growth and a significant inverse relationship between growth during supplementary feeding and growth during the next 111 days. There were, however, no significant differences in growth during lot-feeding, carcass weights, dressing percentages or carcass fatness associated with the previous supplementary feeding treatments. The effects of five different supplements (including the four mentioned above) on the intake of a poor quality roughage by weaner lambs were compared in a preliminary pen-feeding experiment. The supplements (pelleted cottonseed meal, lupins, oats + IBDU, oats + urea, and oats alone) significantly improved roughage consumption by 26-49%. There were no significant differences between supplements.