Breeding successful by using RZ

Since 1876 the German Holstein breeder associations are known for quality and innovation. The German relative breeding values are considered international standard.


A new epoch of breeding healthier and long-lived cows begins with the introduction of the genomic relative breeding values. By using the RZhealth animal health within the herd can be improved in an optimal economically way. Focusing on special health traits, one or more of the four complex breeding values can be used for selective breeding:


  • RZudderfit (includes traits for clinical and subclinical mastitis)
  • RZhoof (includes traits for claw disorders)
  • RZmetabol (includes traits for metabolic disorders)
  • RZrepro (includes traits for reproductive disorders)
  • RZhealth (as an overall breeding value index, composed of all four categories with different economical weighting)


The four complex breeding values contain 13 health traits all together and are combined in the overall breeding value RZhealth.

Vital calves with RZcalfhealth

Icon RZ Calfhealth CMYK
© RZcalfhealth RZKälberfit eng

New from August 2019 RZcalfhealth for sustainable improvement of calf vitality and reduction of calf losses.

Significant data for German breeding success

The base for estimation of direct genomic health breeding values is – besides other research projects- the national project KuhVision. The project includes the collection of health data from more than 650 farms and it's still going on.


International unique is the combination of diagnostic data from farms and data about culled animals from milk performance recording data. For more than 20 years it is a standard procedure in Germany that the reasons for culled animals are recorded with milk performance. Due to the central data processing at the Information provider vit a meaningful data evaluation of the raw data is available.


Although these data are not quite as differentiated as the direct health data, but by the large number of data sets they bring a crucial reliability increase in the health breeding values. The genetic breeding values offer reliabilities between 50 % and 60 % - these values are very high for a health trait and speak for the superior data quality of the German relative breeding values and breeding value estimation methods.


Dairy farmers can now use this unique information for targeted mating and thus for their farm development.