Page 8 - Grampians Angus 2021 Catalogue ebook
P. 8

When using EBVs to assist in selection decisions it is important
      to achieve a balance between the different groups of traits and
      to  place emphasis on  those traits that are important to the
      particular herd, markets and environment. One of the advantages
      of having 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.

      6          Grampians Annual Sale
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