Page 9 - MWC 3-31-2022s
P. 9

The Impact of Bull Selection –Part 1                                                       The Midwest Cattleman · March 31, 2022 · P9

                                            By Mark Z. Johnson

         Let’s take a look at an ex-        In this example, we use
      ample of what happens to ex- herd bulls as rotational
      pected herd performance in  sires, selecting the best 20%
      the next generation based on  of heifers to develop as re-
      the bull we use.                   placements, and sell all other
         First, last  fall  at weaning  calves at weaning.
      we took the following mea-            Since genetic values are
      sures of herd performance.         comparable across time and
         •1,400-pound average ma- geography, we can use the
      ture cow size (4 – 7 year old  registration numbers of the
      cows)                                           continued on page 13
         •85% pregnancy rate
         •82% calf crop weaned
         •Average weaning weight
      500 pounds
         •Pounds of Calf  Weaned/
      Exposed Female = 410
         This data indicates that we
      need to improve the Pounds of
      Calf Weaned/Exposed Female
      on a whole herd basis to im-
      prove the profit potential of
      this operation.  Traits of eco-
      nomic significance to improve
      this number are weaning
      weight, cowherd fertility, cow
      milk level and mature weight
      of cows.   An EPD exists for
      each and can be used as a
      basis of selection to improve
      the 410 value.



            Center, Inc.

             On I-70, 4 miles east of
        Kingdom City, MO on outer road


              Feeder Sale

               12:30 p.m.

         1st Thursday Night
            of Each Month

                6:00 p.m.

          Special Cow Sale

             Jack Harrison

           John P. Harrison

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