The April dairy proofs included several industrywide updates, including the addition of a new trait, a downward trend in Daughter Pregnancy Rate (DPR) and the calculation of crossbred evaluations. Read on so you are in the know on these industry updates.
Early First Calving Added
The Council on Dairy Cattle Breeding (CDCB) now publishes genetic values for a new health trait: Early First Calving (EFC). EFC is defined as age in days at first calving. Animals expected to transmit genetics that decrease the age at first calving have a positive EFC value. This means their offspring should calve sooner, which is more ideal. EFC values for the GENEX lineup are available through your GENEX representative.
Generally speaking, there was a downward trend in DPR values. The CDCB acknowledges this trend and is looking into the reason.
› Jersey DPR values (both genomic and daughter-proven) dropped 0.3 on average.
› Holstein genomic-proven bulls dropped an average of 0.8 DPR, while daughter-proven sires averaged a 0.6 drop in DPR.
These lower DPR values are reflected in the index values (ICC$™, LNM$, CM$, TPI® and JPI™) values for both Holsteins and Jerseys.
For more information, read the CDCB article “About Fertility Evaluations for Young Bulls in April.”
Crossbred Evaluations Now Available
The growing number of commercial dairy herds milking mixed breed composition animals has made the development of crossbred genetic evaluations a reality. With the April proof run, CDCB started calculating crossbred evaluations.
Important notes about the new crossbred evaluations:
› Genetic value estimates for crossbreds are less accurate than purebred estimates. The crossbred genomic predictions are calculated as a weighted average of the respective single breed evaluations.
› Breed Base Representation (BBR) values were updated with this larger reference population (BBR values changed slightly for some animals).
› BBR determines whether a sire has a BLENDED or SINGLE genetic evaluation.
› Any animal with a BBR ≥ 90% is evaluated with the breed of its highest BBR.
› Animals with a BBR < 90% are evaluated in a blended group and their predictions are
based on a weighted combination of marker effects from the different comprising breeds.
With these changes, the GENEX Jersey lineup - and Jerseys industrywide - experienced shifts in genetic values. All active Jersey sires under 90 BBR now have a blended evaluation, more accurately representing the genetic makeup of the animal. Since this is a change from prior proof runs, the genetic evaluations of some animals changed significantly.
For more in-depth information on the crossbred evaluations, view the CDCB webinar.
Connect with us to learn how our world-class cattle genetics, progressive reproductive solutions, and value-added services can advance your operation. Click here to contact us today!