Page 6 - Waiterenui Angus Sale 2021 ebook

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TACE Traits differences in EBVs between animals. Particular animals should be
viewed as being “above or below breed average” for a particular trait.
UNDERSTANDING THE EBVS Whilst EBVs provide the best basis for the comparison of the genetic

An animal’s breeding value is its genetic merit, half of which will be merit of animals reared in different environments and management
passed on to its progeny. While we will never know the exact breeding conditions, they can only be used to compare animals analysed
value, for performance traits it is possible to make good estimates. within the same analysis. Consequently, TransTasman Angus Cattle
These estimates are called Estimated Breeding Values (EBVs). Evaluation EBVs cannot be validly compared with EBVs for any
In the calculation of EBVs, the performance of individual animals other breed.
within a contemporary group is directly compared to the average Although EBVs provide an estimate of an animal’s genetic merit for
of other animals in that group. A contemporary group consists of a range of production traits, they do not provide information for all
animals of the same sex and age class within a herd, run under of the traits that must be considered during selection of functional
the same management conditions and treated equally. Indirect animals. In all situations, EBVs should be used in conjunction with
comparisons are made between animals reared in different visual assessment for other traits of importance (such as structural
contemporary groups, through the use of pedigree links between soundness, temperament, fertility etc). A recommended practice is to
the groups. 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 expressed in the units of measurement for each particular
trait. They are shown as + ive or - ive differences between an EBVs are published for a range of traits covering fertility, calving
individual animal’s genetics difference and the genetic base to which ease, milking ability, growth, carcase merit and feed efficiency. When
the animal is compared. For example, a bull with an EBV of +50 kg using EBVs to assist in selection decisions it is important to achieve a
for 600-Day Weight is estimated to have genetic merit 50 kg above balance between the different groups of traits and to place emphasis
the breed base of 0 kg. Since the breed base is set to an historical on those traits that are important to the particular herd, markets
benchmark, the average EBVs of animals in each year drop has and environment. One of the advantages of having a comprehensive
changed over time as a result of genetic progress within the breed. range of EBVs is that it is possible to avoid extremes in particular
traits and select for animals with balanced overall performance.
The absolute value of any EBV is not critical, but rather the

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