The base for U.S. genetic evaluations will be updated, effective with the April 7, 2020, triannual evaluations. With the base change, users of genetic evaluations may become aware that the standards they set for choosing service bulls or valuing females in the past may no longer meet the genetic quality to remain competitive, due to genetic progress.
Because gains were made across five years for most traits, most of these PTAs will be lowered by the amount shown. However, if the trends were unfavorable, the PTAs will generally increase. The exceptions can be for somatic cell score (SCS) and the four calving traits which may do the opposite because lower values are preferable for these traits. The average PTAs in the table are the differences in transmitting ability for animals over the five-year period. A note of caution, these will not be the exact changes coming because all will be recalculated before the April 2020 run using more complete and current data. Any updates in the traits’ variation will also cause these approximations to vary from the estimates presented. Click here for more.
Calving Ease, Stillbirth Evaluations Enhanced
With the April sire summary, improvements in calving trait evaluations are being made to provide more accurate predictions that reflect current dairy management. The updates are based on findings from a comprehensive review by Dr. Stefano Biffani. These modifications are expected to result in decreasing trends in the calving traits and reranking of animals in April, especially in daughter calving ease (DCE) and daughter stillbirth (DSB). Read the details here.
Disease Resistance (health) Traits for Jerseys
Disease resistance (health) evaluations for six traits (resistance to milk fever, displaced abomasum, ketosis, mastitis, metritis, retained placenta) have been available for Holstein animals since April 2018. Recent research indicated that expanding these evaluations for Jersey animals was feasible, as there has been a 112% increase in the total number of usable Jersey health records since the initial research was completed. Read more here.