Page 8 - Woodbank-Matariki ebook
P. 8

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.
      Days to Calving EBV (days) indicates the fertility of the
      daughters of the sire.  It is the time interval between the
      day when the female is first exposed to a bull in a paddock
      mating to the day when she subsequently calves.  A negative
      EBV for days to calving indicates a shorter interval from
      bull-in date to calving and therefore higher fertility.
      Carcase Weight EBV (kg) is based on abattoir carcase
      records and is an indicator of the genetic differences in
      carcase weight at the standard age of 750 days.
      Eye Muscle Area EBV (sq cm) is calculated from
      measurements from live animal ultrasound scans and from
      abattoir carcase data, adjusted to a standard 400 kg carcase.
      This EBV estimates genetic differences in eye muscle area
      at the 12/13th rib site of a 400 kg dressed carcase.  More
      positive EBVs indicate better muscling on animals.  Sires
      with relatively higher EMA EBVs are expected to produce
      better-muscled and higher percentage yielding progeny at
      the same carcase weight than will sires with lower EMA
      EBVs.
      Rib Fat and Rump Fat EBVs (mm) are calculated from
      measurements of subcutaneous fat depth at the 12/13-rib
      site and the P8 rump site (from live animal ultrasound scans
      and from abattoir carcases) and are adjusted to a standard
      400 kg carcase.  These EBVs are indicators of the genetic
      differences in fat distribution on a standard 400 kg carcase.


      6             Woodbank Angus & Matariki Herefords Bull Sale 2021
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