Page 14 - Te Mania Angus 2021 Catalogue eBook

UNDERSTANDING EBVS

AND HOW TO USE THEM

The TransTasman Angus Cattle Evaluation (TACE) is an advanced genetic evaluation system that
provides a genetic description of Angus cattle for a large range of traits influencing fertility, growth,
maternal and carcase performance. It provides predictions of the genetic merit of individual animals

called Estimated Breeding Values (EBVs).

EBVs are based on all the available pedigree and performance records provided by breeders in
Australia and New Zealand, along with available overseas genetic information.

EBVs are expressed in the units of measure for each particular trait, and are shown as positive (+)
or negative (-) values. The average EBV for different traits changes over time as the breed makes
genetic progress. The averages for calves born in 2011 are shown at the bottom of each page and the
percentile bands are shown on Page 16. The averages and percentile bands are the easiest way to
compare the merits of particular animals.
Accuracy (%) Provides an indication of the reliability of an EBV. As more performance information
becomes available on an animal, its progeny and relatives, the accuracy of its EBVs for particular traits
increases. The higher the accuracy, the less chance that the figure for each EBV will change.
Calving Ease Direct (%) CE Dir This tells us the amount of calving ease we can expect from a
particular bull, relating directly to the females he is joined to. The calving ease figures will generally only
appear on the chart of a sire, but can also appear on a younger bull’s chart if there has been a lot of
information gathered on his relatives. A positive value here is better.

Calving Ease Daughters (%) CE Dtrs This tells us the amount of calving ease we can expect from a
particular bull’s daughters. A positive value here is better.
Gestation Length (Days) This figure gives us a value relating to the number of days from the date of
conception to the calf birth date. A shorter gestation length is better as it gives more time for the cow
to get back into calf and there is less chance of the calf getting too big in the uterus and increasing the
chances of calving difficulties. A negative value here is better

Birth Wt (kg) Birth weight gives us an indication of how much the calves of a particular animal will
weigh at birth. This figure should be monitored, but be careful not to go too low as this can cause
problems with calf mortality and calving ease down the track. We must also remember that only a small
percentage of calving ease is related to birth weight.

200-Day Wt (kg), 400-Day Wt (kg), 600-Day Wt (kg) Estimates the genetic differences between
animals in liveweight at 200, 400 and 600 days of age. For example, if you have two bulls, one with a
600 day weight figure of +70 and the other with a figure of +80, you would expect the bull who is +80
to sire calves that would average 5kgs heavier at 600 days than the other sire (the sire provides 50% of
the genes to the calf, 10kgs divided by 2). A higher positive value for these growth figures is better.
Mature Cow Weight (kg) This figure provides an estimate of the genetic differences between animals
in cow weight at 5 years of age. We try to keep this figure below the 600 Day Weight Figure. Where this
is the case in the catalogue we have highlighted the mature cow figure in red.
Milk (kg) The Milk Figure provides an estimate of the genetic differences between animals in milk
production, expressed as a variation in the 200-day weight of their daughter’s calves. Angus cattle
generally don’t have a problem providing enough milk for their offspring so we don’t need to worry too
much about pushing this figure. Too much milk can lead to udder problems and difficulty getting back in

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