Breeding goal definition and index selection for Austrian cattle population.

The aim of the study was to define the breeding goal for the predominant cattle breeds in Austria - Fleckvieh, Brown Swiss, Holstein Friesian, Pinzgauer and Grey cattle - under the new production circumstances after joining the EU and to implement a total merit index. The economic values were estimated for milk and beef production traits and functional traits under three different quota scenarios: in Scenario I, no quota was assumed, in Scenario II a quota on milk with a reference fat content was assumed and in Scenario III the quota was on the sum of fat and protein yields. The derivation of economic values was based on a model simulating an average herd for each breed. Economic values for milk production traits were sensitive to the assumed quota situation while the economic values for beef production traits and functional traits were insensitive. The relative economic value of the milk production traits was lower under Scenario II and III. Functional traits were of considerable economic importance and should therefore be included in the aggregate genotype. For the calculation of the total merit index (TMI) and subindices for milk, beef and fitness, which were calculated separetely from the TMI, it was assumed that estimated breeding values (EBV) for all the breeding goal traits will be avalailable. The weighting factors in the selection index depend on the reliabilities of the EBV and will therefore be different from animal to animal.