Page 10 - TwinOaks Angus 2021 Catalogue eBook

group/herd. For sires, this cross linkage is usually achieved through
AI but could also be through common dams.
TACE uses “multiple trait” evaluation which further increases the
accuracy of the EBVs
Because there is usually a genetic association between different
traits (which may be positive or negative and vary from weak to
strong) this information can be used enhance measurements of
recorded traits or estimate an animal’s breeding value for traits that
have not been directly measured.
TransTasman Cattle Evaluation is a modern genetic evaluation For example, 200 day weight has a positive association with 400
programme for beef cattle breeders. It compares cattle on the day weight – that is, as 200 day weight increases so does 400 day
basis of their breeding values. weight.
TransTasman Cattle Evaluation (TACE) is formerly known as The multiple trait analysis also helps to reduce the “bias” which can
BreedPlan. TACE provides predictions of the genetic merit of be introduced by a previous selection decision, say selective joining
individual animals called Estimated Breeding Values (EBVs). These or dis-proportional culling. For example, culling of lighter calves at
EBVs are used by Angus breeders and bull buyers to assist in weaning will give higher group average 400 day weight. The fact that
selection decisions and purchase of breeding stock. the remaining animals have a higher group average as a result of
previous culling is accounted for in TACE as long as the records of
EBVs are based on all available pedigree and performance records the previously culled animals are included in the evaluation.
provided by breeders in New Zealand and Australia, along with
available overseas genetic information. EBVs provide the best means EBVs are expressed in the same units as they were measured (eg,
for comparison of the relative genetic merit of animals across the kg) and are estimated relative to the breed benchmark of zero, which
breed for those traits included in the analysis. EBVs obviously cannot was established at the time of the first analysis.
be used in isolation in any selection or purchase decision. Visual
assessment is still necessary for those characteristics not adequately WHAT DOES TACE DO?
described by EBVs. TACE adjusts field measurements (raw data) submitted by

GROUP TACE EBVs have been proven to be more accurate than raw the breeder to calculate an estimate of the animals breeding
performance measurements for assisting in the selection of breeding value (EBV). It uses information from the performance of the
stock. Research results and industry experience has shown that individual animal as well as its relatives, and allows for differences
more rapid genetic gains can be achieved in herds which make use in environment and chance that animals have been exposed to and
of EBVs in their selection decisions. In the calculation of EBVs all that would otherwise bias our selection decisions.
available pedigree and performance information on each animal and It provides the best estimate of an animal’s breeding value from
its relatives (parents, ancestors, siblings, progeny, etc.) is combined the information available.
to provide a single best estimate of an individual’s genetic merit
for each trait. In addition, allowance is made for environmental TACE is a useful aid to selection, not because you are a poor judge
differences between properties, seasons and management groups of cattle but because when it comes to long term memory recall
on each animal’s performance. Differences in heritabilities between or making simultaneous adjustments for known environmental
traits and genetic associations between traits are also accounted for effects over a number of traits, human brain power is no match for a
in the calculation of EBVs. computer.

AN OVERVIEW OF TACE. WHY USE TACE TO ANALYSE
What you see in an animal is the effect of genes they inherit from PERFORMANCE RECORDS?
their parents modified by the effect of non-genetic (environmental) What we see or measure in an animal is influenced by both
factors such as feeding and parasite control, sex, age of dam etc. environmental and genetic factors.
To improve your herd by selection, you need to evaluate the genetic Environmental factors influence the way an animal may look or
merit of cattle – that is the proportion of the animals performance perform within a given environment but not the way his progeny
which is controlled by its genes, and not its overall performance will look or perform within a different environment. Environmental
which has been influenced by environmental and other non-genetic influences include nutrition (differences between paddocks or
effects. properties, supplementary feeding, or trace mineral capsules),
management such as castration and drenching, grooming and
Early approaches to performance recording used the ratio system. clipping, gut-fill, ill-health, and parasites.
The animals performance was corrected for sex, age of calf and
age of dam, and then compared as a percentage to other animals Observed differences of performance between animals resulting
within the same management group. Comparison of animals across from differences in environment can be large, but are not inherited
management groups, herds or years was not possible using this by their progeny, and as such can lead our selection decision astray.
system.
Genetic factors are the result of genes inherited from the parents
TACE represents a major improvement over the more traditional and are the blueprint for future performance, both of the individual
methods of performance recording. It uses all the records and its progeny.
available on the animal and its relatives to disentangle genetic You buy a bull not for what he looks like but how his progeny will
and environmental factors, giving the best estimate of the animals perform. It is only when environment factors are either standardised
breeding value that is possible from the available information.
or adjusted for that real genetic differences become apparent.
To allow comparison of animals from between management groups
or even different properties genetic links between contemporary TACE uses sophisticated computing technology to adjust for known
groups are essential. A genetic link is achieved where animals in one environmental effects over a number of selection traits.
group/herd have a parent in common with an animals in another