DairyTalk 232: From Brachyspina to HH6 - Genetic Defects in Holsteins - by Helmut Demmelhuber

This article provides a structured overview of the most relevant
genetic defects in Holstein cattle and explains how genomic data
enables responsible breeding decisions. It covers lethal
conditions such as Brachyspina, CVM, and BLAD, as well as less
visible risks like Holstein Haplotypes HH1–HH6 and Cholesterol
Deficiency, which often manifest through fertility issues or high
calf mortality. The key message is clear: carrier animals can
remain valuable contributors to genetic progress, but only when
managed through precise mating strategies. Sustainable breeding
success depends on combining performance, transparency, and
disciplined genetic risk management.