Page 4 - Kia Toa Charolais Catalogue ebook

EBV’S EXPLANATION

Estimated Breeding Values (EBV’S)
EBVs for the growth traits are calculated in kilograms. The EBV is
the best estimate of an animals genetic merit for that trait.
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 % Dir = 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 = Daughter’s Calving Ease - The EBV for
daughters’ calving ease indicates how easily that sire’s daughters
will calve at two years of age.
Gestation Length (days) is an estimate of the time from
conception to the birth of the calf and is based on AI 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.
Smaller, or more moderate EBVs are generally more favourable.
The Mature Cow Weight EBV may also be used by steer breeders
wishing to grow animals out to a larger weight.
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 and 400 day weights of
her calves. For dams, it indicates her own milking ability.
Scrotal Size EBV (cm) is calculated from the circumference of the
scrotum, measured in centimetres and adjusted to 400 days of
age. This EBV is an estimate of a sire’s genetic merit for scrotal size
and is positively correlated to age of puberty in female progeny.
Days to Calving (days) - This EBV indicates the fertility of the
daughters of the sire. It is the time interval between the date
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
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