Page 6 - Blenheim 2021 Catalogue ebook

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.
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

BLENHEIM BULL SALE
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