A SIMULATION STUDY OF THE EFFECT OF CONNECTEDNESS ON GENETIC TREND

A breeding scheme was simulated with four subpopulations over seven se parate generations. Males were progeny tested before selection. A vary ing proportion of link sires were used across populations to estimate the genetic level of each subpopulation. The male replacement policy a llowed some gene flow across subpopulations. Without any connection be tween subpopulations, the genetic differences between subpopulations w ere not estimable and the overall genetic trend was limited. With few connections (proportion of link sires = 1/16), the accuracy of the con trast between subpopulations was poor but the gene flow between subpop ulations made it possible to increase the overall genetic trend, parti cularly for the first generations. A high level of connections improve d the accuracy of the genetic evaluation but only slightly increased t he genetic trend.