Page 7 - Ariki ebook

on EBVs and to then select from this group to ensure that the
final selections are otherwise acceptable.
EBVs are published for a range of traits covering fertility, calving
ease, milking ability, growth, carcase merit and feed efficiency.
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

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