DairyTalk 431: RZE vs. PTAT: Two breeding systems built for completely different outcomes - by Helmut Demmelhuber

This podcast episode is based on a technical article examining
the fundamental differences between the German RZE system and the
American PTAT approach in Holstein breeding. At the center is the
question of why both systems evaluate similar type traits but
pursue entirely different breeding objectives. While RZE is
designed around functional, durable, and economically efficient
cows for modern commercial housing systems, PTAT has
traditionally placed greater emphasis on visual style and
show-ring appeal. The analysis explains why direct numerical
comparisons between the systems are misleading and how different
countries define the “ideal cow” in very different ways. At the
same time, the discussion highlights a broader industry shift
toward efficiency, robustness, and lifetime performance instead
of extreme type selection.