Page 8 - Brackenfield 2020
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a comprehensive range of EBVs is that it is possible to avoid
      extremes in particular traits and select for animals with balanced
      overall performance.
      Calving Ease EBVs (%) are based on calving difficulty scores, birth
      weights and gestation length information.  More positive EBVs are
      favourable and indicate easier calving.
      CE % Direct = Direct Calving Ease - The EBV for direct calving
      ease indicates the influence of the sire on calving ease in purebred
      females calving at two years of age.
      CE % Daughters = Daughters’ Calving Ease -  The EBV for
      daughters’ calving ease indicates how easily that sire’s daughters
      will calve at two years of age.
      Gestation  Length EBV  (days)  is  an  estimate  of  the time  from
      conception to the birth of the calf and is based on AI and hand
      mating records. Lower (negative) GL EBVs indicate shorter
      gestation length and therefore easier calving and increased
      growth after birth.
      Birth Weight EBV (kg) is based on the measured birth weight of
      progeny, adjusted for dam age. The lower the value, the lighter the
      calf at birth and the lower the likelihood of a difficult birth. This is
      particularly important when selecting sires for use over heifers.
      200-Day Growth EBV (kg) is calculated from the weight of progeny
      taken between 80 and 300 days of age. Values are adjusted to 200
      days and for age of dam. This EBV is the best single estimate of an
      animal’s genetic merit for growth to early ages.
      400-Day  Weight EBV (kg)  is calculated from the weight of
      progeny taken between 301 and 500 days of age, adjusted to 400
      days and for age of dam. This EBV is the best single estimate of an
      animal’s genetic merit for yearling weight.
      600-Day  Weight EBV (kg)  is calculated from the  weight of
      progeny taken between 501 and 900 days of age, adjusted to 600
      days and for age of dam. This EBV is the best single estimate of an
      animal’s genetic merit for growth beyond yearling age.
      Mature Cow Weight EBV (kg) is based on the cow weight when
      the calf is weighed for weaning, adjusted to 5 years of age. This EBV
      is an estimate of the genetic difference in cow weight at 5 years of
      age and is an indicator of growth at later ages and potential feed
      maintenance requirements of the females in the breeding herd.
      Steer breeders wishing to grow animals out to a larger weight may
      also use the Mature Cow Weight EBV.
      Milk  EBV (kg)  is an estimate of an animal’s milking ability. For
      sires, this EBV indicates the effect of the daughter’s milking ability,
      inherited from the sire, on the 200-day weights of her calves. For
      dams, it indicates her milking ability.
      Scrotal Size EBV (cm) is calculated from the circumference of the
      scrotum taken between 300 and 700 days of age and adjusted to
      400 days of age. This EBV is an estimate of an animal’s genetic merit
      for scrotal size. There is also a small negative correlation with age
      of puberty in female progeny and therefore selection for increased
      scrotal size will result in reduced age at calving of female progeny.
      6                                   BRACKENFIELD
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