Page 8 - Wairere 2021 Catalogue ebook

compared. For example, a bull with an EBV of +50 kg for on calving ease in purebred females calving at two
600-Day Weight is estimated to have genetic merit 50 kg years of age.
above the breed base of 0 kg. Since the breed base is CE % Daughters = Daughters' Calving Ease – The
set to an historical benchmark, the average EBVs of EBV for daughters' calving ease indicates how easily
animals in each year drop has changed over time as a that sire's daughters will calve at two years of age.
result of genetic progress within the breed.
Gestation Length EBV (days) is an estimate of the time
The absolute value of any EBV is not critical, but rather from conception to the birth of the calf and is based on AI
the differences in EBVs between animals. Particular and hand mating records. Lower (negative) GL EBVs
animals should be viewed as being "above or below indicate shorter gestation length and therefore easier
breed average" for a particular trait. calving and increased growth after birth.

Whilst EBVs provide the best basis for the comparison of Birth Weight EBV (kg) is based on the measured birth
the genetic merit of animals reared in different weight of progeny, adjusted for dam age. The lower the
environments and management conditions, they can only value, the lighter the calf at birth and the lower the
be used to compare animals analysed within the same likelihood of a difficult birth. This is particularly important
analysis. Consequently, NZ ANGUS BREEDPLAN when selecting sires for use over heifers.

EBVs cannot be validly compared with EBVs for any 200-Day Growth EBV (kg) is calculated from the weight
other breed. of progeny taken between 80 and 300 days of age.
Values are adjusted to 200 days and for age of dam. This
Although EBVs provide an estimate of an animal’s EBV is the best single estimate of an animal's genetic
genetic merit for a range of production traits, they do not merit for growth to early ages.
provide information for all of the traits that must be
considered during selection of functional animals. In all 400-Day Weight EBV (kg) is calculated from the weight
situations, EBVs should be used in conjunction with of progeny taken between 301 and 500 days of age,
visual assessment for other traits of importance (such as adjusted to 400 days and for age of dam. This EBV is the
structural soundness, temperament, fertility etc). A best single estimate of an animal's genetic merit for
recommended practice is to firstly select breeding stock yearling weight.
based on EBVs and to then select from this group to
ensure that the final selections are otherwise acceptable. 600-Day Weight EBV (kg) is calculated from the weight
of progeny taken between 501 and 900 days of age,
EBVs are published for a range of traits covering fertility, adjusted to 600 days and for age of dam. This EBV is the
calving ease, milking ability, growth, carcase merit and best single estimate of an animal's genetic merit for
feed efficiency. When using EBVs to assist in selection growth beyond yearling age.
decisions it is important to achieve a balance between Mature Cow Weight EBV (kg) is based on the cow
the different groups of traits and to place emphasis on weight when the calf is weighed for weaning, adjusted to
those traits that are important to the particular herd, 5 years of age. This EBV is an estimate of the genetic
markets and environment. One of the advantages of difference in cow weight at 5 years of age and is an
having a comprehensive range of EBVs is that it is indicator of growth at later ages and potential feed
possible to avoid extremes in particular traits and select maintenance requirements of the females in the breeding
for animals with balanced overall performance. herd. Steer breeders wishing to grow animals out to a
larger weight may also use the Mature Cow Weight EBV.
Calving Ease EBVs (%) are based on calving difficulty
scores, birth weights and gestation length Milk EBV (kg) is an estimate of an animal's milking ability.
information. More positive EBVs are favourable and For sires, this EBV indicates the effect of the daughter's
indicate easier calving. milking ability, inherited from the sire, on the 200-day
CE % Direct = Direct Calving Ease - The EBV for weights of her calves. For dams, it indicates her milking
direct calving ease indicates the influence of the sire ability.