Page 8 - Merchiston Angus Catalogue ebook

EBVs EXPLAINED

An animal's breeding value is its genetic merit, half of which will be passed on to its progeny. While we will never know the
exact breeding value, for performance traits it is possible to make good estimates. These estimates are called Estimated
Breeding Values (EBVs).
In the calculation of EBVs, the performance of individual animals within a contemporary group is directly compared to the
average of other animals in that group. A contemporary group consists of animals of the same sex and age class within a
herd, run under the same management conditions and treated equally. Indirect comparisons are made between animals
reared in different contemporary groups, through the use of pedigree links between the groups.
EBVs are expressed in the units of measurement for each particular trait. They are shown as + ive or - ive differences between
an individual animal's genetics difference and the genetic base to which the animal is compared. For example, a bull with an
EBV of +50 kg for 600-Day Weight is estimated to have genetic merit 50 kg above the breed base of 0 kg. Since the breed
base is set to an historical benchmark, the average EBVs of animals in each year drop has changed over time as a result of
genetic progress within the breed.
The absolute value of any EBV is not critical, but rather the differences in EBVs between animals. Particular animals should be
viewed as being "above or below breed average" for a particular trait.
Whilst EBVs provide the best basis for the comparison of the genetic merit of animals reared in different environments and
management conditions, they can only be used to compare animals analysed within the same analysis. Consequently,
TRANSTASMAN ANGUS CATTLE EVALUATION EBVs cannot be validly compared with EBVs for any other breed.

Although EBVs provide an estimate of an animal’s genetic merit for a range of production traits, they do not provide information
for all of the traits that must be considered during selection of functional animals. In all situations, EBVs should be used in
conjunction with visual assessment for other traits of importance (such as structural soundness, temperament, fertility etc). A
recommended practice is to firstly select breeding stock based 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 ANGUSPURE PARTNER STUD EXTRA ANGUSPURE
ages. AngusPure NZ has teamed up with 88 Angus studs who share ENDORSEMENT FOR MARBLING
400-Day Weight EBV (kg) is calculated from the weight of progeny taken between 301 and 500 days of age, adjusted to 400 in our vision - to focus on the end consumer. This stud is proud In addition to the ‘A’, and to assist bull buyers who wish to select

days and for age of dam. This EBV is the best single estimate of an animal's genetic merit for yearling weight. to be named as one of them, and by using the finest genetics for more marbling we are rewarding those animals that are in the
and implementing best management practice they can help you top 25% of the breed for AngusPure index and who also have
600-Day Weight EBV (kg) is calculated from the weight of progeny taken between 501 and 900 days of age, adjusted to 600 produce more premium quality Angus beef. their marbling EBV (IMF) in the top 50% as well. These bulls will be
days and for age of dam. This EBV is the best single estimate of an animal's genetic merit for growth beyond yearling age. Only our AngusPure Partner studs display these devices in their sale awarded an ‘A+’ endorsement. Marbling is one of the very highest
catalogues. They indicate bulls endorsed by AngusPure NZ. eating quality attributes and is necessary in order to meet some of
Mature Cow Weight EBV (kg) is based on the cow weight when the calf is weighed for weaning, adjusted to 5 years of age. the highest premium requirements for our new program, AngusPure
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 Special Reserve. To qualify for the ‘A+’ endorsement, bulls must meet
potential feed maintenance requirements of the females in the breeding herd. Steer breeders wishing to grow animals out to a ANGUSPURE ENDORSED BULLS a minimum AngusPure index of +$141. They must also meet the
larger weight may also use the Mature Cow Weight EBV. minimum marbling requirement of +1.7 for IMF
AngusPure continues to endorse bulls for sale that are in the top 40% of the
Milk EBV (kg) is an estimate of an animal's milking ability. For sires, this EBV indicates the effect of the daughter's milking breed for AngusPure index. This index gives commercial farmers confidence These bulls will be => +$141 for AngusPure index and => + 1.7

ability, inherited from the sire, on the 200-day weights of her calves. For dams, it indicates her milking ability. that by using this selection tool, bulls are most likely to leave progeny with for IMF EBV.
Scrotal Size EBV (cm) is calculated from the circumference of the scrotum taken between 300 and 700 days of age and superior carcase quality and at the same time achieve desirable outcomes for AngusPure recognises the need to lift the amount of marbling in

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 self replacing herds, as the AngusPure index still rewards cattle with strong our New Zealand cow genetics, in order to fill the requirements of
maternal attributes like calving ease, scrotal and growth, along with carcase
negative correlation with age of puberty in female progeny and therefore selection for increased scrotal size will result in weight. To qualify for the ‘A’ endorsement, bulls must meet a minimum consumers going forward. Marbling has two critical components;
reduced age at calving of female progeny. AngusPure index of +$120. genetics and feeding. Feeding on a rising plane of nutrition is vital
but without the genetics these attributes will not be able to express
These bulls will be => +$120 for AngusPure index. themselves.
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