Effect of Energy Levels Provided Ewe Lambs Post-Weaning on their Development and Subsequent Production

Replacement ewe lambs are usually fattened along with the wethers. This high feed intake, though normally followed by several months of maintenance feeding prior to breeding, results in a high cost to the sheep industry. Furthermore, a high condition in ewe lambs may be undesirable. Pinney et al. (1962) reported that open heifers fed energy levels during their first winter that resulted in high condition, were less productive in subsequent years. Bradford, Weir and Torell (1961) compared ewes raised from 6 to 17 months of age on either an unsupplemented dry range or on irrigated legume pasture. Although the ewes raised under dry range conditions were 25% lighter, produced significantly less wool as yearlings and remained significantly lighter through 3 years in a common environment, the first year's environment did not adversely affect their lifetime lamb production. Purser and Roberts (1964) noted large yearling body and fleece weight differences between ewe lambs wintered on abundant feed and those wintered on poor hay under hill conditions in Scotland.