DairyTalk 230: Index vs. Trait: The Most Common Genomic Misunderstanding - by Helmut Demmelhuber

Modern genomic data sheets provide an unprecedented level of
detail – yet they are often misinterpreted. This article
clarifies the fundamental difference between breeding values like
RZG and genetic traits. While RZG reflects an animal’s overall
genetic quality for production, health, and longevity, genetic
markers function as binary risk indicators for defects, fertility
haplotypes, or traits such as horn status and milk protein
variants. Being a carrier does not disqualify an animal, but it
requires strategic mating decisions. The piece shows why
successful breeding depends on combining index-based quality
assessment with targeted risk management – and how ignoring this
distinction can lead to fertility issues, mating failures, or
flawed herd decisions.