Possibilities and requirements for organic dairy breeding lines

Summary

Possibilities and requirements for organic dairy breeding lines
Until now, improvements in the efficiency of organic dairy production have mainly occurred through better management, feeding and production strategies, using the dairy cattle breeds developed in conventional production systems. The potential of breeding lines of dairy cattle that are genetically adapted to organic milk production is essentially unexploited even though specific lines offer the potential to breed for cows with specific characteristics.
The main reason why organic lines of dairy cattle not have been established in the past is most likely based on the assumption that the correlation between the breeding goals in the two production systems is above 0.8. As a correlation higher than that, assuming that the testing capacity used for progeny testing bulls was the overall driver of genetic gain, has been shown to cause loss of genetic gain in lines of size less than a million cows. With the recent implementation of genomic selection in dairy cattle breeding, the overall driver seems to have changed to the size of the reference population which can be considerable even in a small population (< 100,000 cows), if it is made up of individual cows. Therefore the critical limit regarding the correlation between breeding goals are higher now. Two main factors affect this correlation. The first is the economic values in the breeding goal. The second is the presence of biological genotype-by-environment interactions
Given different economic values and G*E interactions this indicates a new potential for establishing different lines of conventional and organic dairy cattle and thereby further improve the efficiency of organic dairy production through selective breeding. Possibilities and requirements for setting efficient organic dairy breeding lines will be discussed in this presentation.