Figure 1

Maximum long-term rates of genetic gain realised by optimum-contribution selection (OCS) without and with restrictions. Breeding scheme applying OCS without restrictions is Unrestricted OCS (dark-shaded bar). Schemes applying OCS with restrictions are Truncated dams, Dams unknown, One-chance (representing breeding scheme, one-chance OCS of sires), Pre-selection of sires 25, 10, 5, 1, and 0.5%, Sire multiples 5, 10, 20, 50, and 100, Offspring unknown, and Multiple (multiple restrictions). These schemes are presented as light-shaded bars, except those that failed to realise most of the long-term genetic gain realised by Unrestricted OCS (unshaded bars). Long-term rate of genetic gain realised by a conventional scheme with truncation selection (TS) is presented as a reference point (dotted line). Long-term refers to generations 23 to 25 (approximately). The rates are means of 100 simulation replicates. The means had standard deviations ranging from 5.8 to 12.0. The rates were scaled by setting to 100 the maximum long-term rate of genetic gain realised by OCS without restrictions. Rate of genetic gain at 100 is equivalent to 0.215 genetic-standard deviations per time and approximately 0.9 genetic-standard deviations per generation.