Influence of Economic Weights and Population Structure on Selection Response of Milk and Beef Traits

Summary

The effect of economic weights and population structure on selection response of milk and beef traits was investigated by aid of model calculation.

The economic weights of dairy traits calculated on national level are lower than on farm level.The reverse is true for beef traits. If the breeding objective is determined on farm level one gets a satisfactory selection response on both farm level and on national level. Therefore, the breeding objective should be determined on farm level. Otherwise the breeder runs the risk that the farmer buys his breeding stock somewhere else.

The optimal proportion of active breeding population proves to be around 50 to 60%. In this region there are combined a high profit with a satisfactory genetic gain.

Compared with milk recording the testing system for beef traits is underdeveloped. The extension of performance testing stations for bulls as well as the introduction of progeny test of bulls and performance test of cows in the field, yield a higher genetic gain and a higher profit. Moreover, these breeding activities seem to be an effective tool to balance the genetic gain of milk and beef traits.