In sheep, where artificial insemination programs are not widespread, management units may be relatively isolated from each other genetically. The changes in estimated breeding values for lamb weight depending on degree of genetic connectedness between flocks were studied in Suffolk sheep breed. Correlation coefficients between breeding values for 100 day lamb weight estimated by variants wíth different degree of connectedness between management units varied from r=0,898 to 0, 997 for direct genetic effect and from r=0,587 to 0, 973 for maternal genetic effect.