DEFINING MULTIPLE-TRAIT OBJECTIVES FOR SUSTAINABLE GENETIC-IMPROVEMENT

Genetic improvement is inherently a long-term process in which progres s in the future is built upon improvement in the past. Discounting of future returns is often used in deriving economic values of traits und er selection, but this gives a shortterm perspective that is in confli ct with the long-term nature of genetic improvement. Changes in manage ment, market environment, and genetic potential over time can negative ly affect the attainment of breeding goals. Nonlinear optimization tec hniques can be used to find optimum economic weights each year over an y time horizon. Nearly optimal solutions can be found by deriving econ omic weights for a single, specified future date. Uncertainty about fu ture production and marketing environments creates risk that might be lessened by maintaining or selecting for diverse genetic stocks that c ould be used in the future. Such programs may need to be coordinated i nternationally because they may be too expensive for individual compan ies to undertake. Consideration of risk and careful analyses of future technical and environmental conditions are needed to define multiple trait objectives for long-term genetic change.