26 January 1996

Economic index added

CHANGES to Canadian bull proofs evaluations have been introduced in the countrys latest evaluation run.

The lifetime profitability index (LPI) has been revised to put more emphasis on protein production and type, particularly functional traits such as feet and legs and udders.

Published alongside LPI is a new total economic value (TEV) index calculated from production figures, herdlife traits, and somatic cell scores to give each bull a profit value in Canadian dollars.

Herdlife is measured directly by looking at survival of daughters in their first, second and third lactations and indirectly using type traits linked to herdlife such as feet and legs, udders, rumps, and capacity.

To bring production evaluations more in line with other countries milk, fat and protein, proofs will now be expressed as estimated breeding values (EBVs) in kg rather than as Canadian breed class averages (BCAs).

There has been a further change to sire type proofs which are now calculated using the first type classification of progeny in their first lactation instead of using the latest classification results. These are shown in a new conformation score, also included in the LPI.