Page 8 - Monymusk Herefords Catalogue eBook.pdf

EXPLANATORY NOTES 600-DAY WEIGHT EBV (KG) is calculated from the weight of
progeny taken between 501 and 900 days of age, adjusted to 600
CALVING EASE EBVS (%) are based on calving difficulty scores, days and for age of dam. This EBV is the best single estimate of an
birth weights and gestation length information. More positive EBVs animal’s genetic merit for growth beyond yearling age.
are favourable and indicate easier calving.
MATURE COW WEIGHT EBV (KG) is based on the cow weight
CE % DIRECT = Direct Calving Ease - The EBV for direct when the calf is weighed for weaning, adjusted to 5 years of age. This
calving ease indicates the influence of the sire on calving ease in EBV is an estimate of the genetic difference in cow weight at 5 years
purebred females calving at two years of age. of age and is an indicator of growth at later ages and potential feed
maintenance requirements of the females in the breeding herd. Steer
CE % DAUGHTERS = Daughters’ Calving Ease - The EBV breeders wishing to grow animals out to a larger weight may also use
for daughters’ calving ease indicates how easily that sire’s the Mature Cow Weight EBV.
daughters will calve at two years of age.
MILK EBV (KG) is an estimate of an animal’s milking ability. For
GESTATION LENGTH EBV (DAYS) is an estimate of the time from sires, this EBV indicates the effect of the daughter’s milking ability,
conception to the birth of the calf and is based on AI and hand mating inherited from the sire, on the 200-day weights of her calves. For
records. Lower (negative) GL EBVs indicate shorter gestation length dams, it indicates her milking ability.
and therefore easier calving and increased growth after birth.
SCROTAL SIZE EBV (CM) is calculated from the circumference of
BIRTH WEIGHT EBV (KG) is based on the measured birth weight the scrotum taken between 300 and 700 days of age and adjusted to
of progeny, adjusted for dam age. The lower the value the lighter the 400 days of age. This EBV is an estimate of an animal’s genetic merit
calf at birth and the lower the likelihood of a difficult birth. This is for scrotal size. There is also a small negative correlation with age
particularly important when selecting sires for use over heifers. of puberty in female progeny and therefore selection for increased
200-DAY GROWTH EBV (KG) is calculated from the weight of scrotal size will result in reduced age at calving of female progeny.
progeny taken between 80 and 300 days of age. Values are adjusted DAYS TO CALVING EBV (DAYS) indicates the fertility of the
to 200 days and for age of dam. This EBV is the best single estimate daughters of the sire. It is the time interval between the day when
of an animal’s genetic merit for growth to early ages. the female is first exposed to a bull in a paddock mating to the day
400-DAY WEIGHT EBV (KG) is calculated from the weight of when she subsequently calves. A negative EBV for days to calving
indicates a shorter interval from bull-in date to calving and therefore
progeny taken between 301 and 500 days of age, adjusted to 400 higher fertility.
days and for age of dam. This EBV is the best single estimate of an
animal’s genetic merit for yearling weight.
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