Page 35 - C-B Charolais Bull & Heifer Production Sale – March 26, 2024
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AICA EPD Guide


        Calving Ease Direct EPD (CE) is expressed as a difference in
         percentage of unassisted births in first calf heifers. A higher value
         indicates greater calving ease. It predicts the average difference
         in unassisted births with which a sire’s calves will be born when
         bred to first-calf heifers.

        Birth Weight EPD (BW) The expected difference in average birth
         weight (pounds) of progeny. Birth weight reflects prenatal growth.

        Weaning Weight EPD (WW) The expected difference in average
         weaning weight of calves. The evaluation reflects the genetic
         influence on pre-weaning growth rate.

        Yearling Weight EPD (YW) The expected difference in average
         yearling weight of progeny. The evaluation reflects genetic
         influence on both pre-weaning and post-weaning growth rate.

        Maternal Milk EPD (MILK) The genetic ability of a sire’s or
         dam’s daughters to express in pounds of weaning weight in her
         calves due to her maternal ability through mothering instinct and
         milk.

        Calving Ease Maternal EPD (MCE) is expressed as a difference
         in percentage of unassisted births in first calf daughters. A higher
         value indicates greater calving ease. It predicts the average
         difference in unassisted births with which a sire’s daughters will
         calve as first-calf heifers when compared to daughters of other
         sires.

        Total Maternal EPD (MWW) A value to predict the weaning
         weight performance of calves from a animal’s daughters due
         to genetics for growth and maternal ability. Total Maternal is
         calculated by adding ½ the WW EPD to the Maternal Milk EPD.

        Terminal Sire Index (TSI) The AICA Terminal Sire Index is a
         formal method of combing Expected Progeny Differences (EPD)
         – BW, WW, YW, REA, CW, MARB and FAT – into one single value
         on which to base selection decisions. The TSI uses estimates of
         the genetic relationships between traits with an economic default
         value based on three year rolling USDA data.

          The TSI represents a dollar index per terminal progeny produced
         for a bull in the AICA database, ranking them for profit potential.
         This dollar index is to be interpreted much like single trait EPD.
         For example, if Sire A’s index is $191.66 and Sire B’s index is
         $200.00, then we would expect Sire B’s offspring to average
         $8.34 more net return ($200.00 minus $191.66) than Sire A’s
         offspring.
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