Page 9 - Tangihau Angus Catalogue 2021 ebook

TACE EBVS - HOW TO USE THEM

TransTasman Angus Cattle Evaluation calculates 200-Day Wt (kg), 400-Day Wt (kg), 600-Day Wt (kg)
predictions of genetic merit called EBVs for a range of Estimates the genetic differences between animals
traits on a national across-herd basis. in liveweight at 200, 400 and 600 days of age. For
example, if you have two bulls, one with a 600 day
The EBVs are calculated using information on the weight figure of +70 and the other with a figure of +80,
animal’s own performance plus the performance of you would expect the bull who is +80 to sire calves
all known relatives (sire, dam, half-sister and brother that would average 5kgs heavier at 600 days than the
etc.), the relationship between the traits and the other sire (the sire provides 50% of the genes to the
pedigree links between animals and between herds. calf, 10kgs divided by 2). A higher positive value for
these growth figures is better.
EBVs are based on all the available pedigree and
performance records provided by breeders in Mature Cow Weight (kg) This figure provides an
Australia and New Zealand, along with available estimate of the genetic differences between animals
overseas genetic information. in cow weight at 5 years of age. We try to keep this

EBVs are expressed in the units of measure for figure below the 600 Day Weight Figure. Where this
each particular trait, and are shown as positive (+) is the case in the catalogue we have highlighted the
or negative (-) values. The average EBV for different mature cow figure in red.
traits changes over time as the breed makes genetic Milk (kg) The Milk Figure provides an estimate of the
progress. The averages for calves born in 2011 are genetic differences between animals in milk production,
shown at the bottom of each page and the percentile expressed as a variation in the 200-day weight of their
bands are shown on Page 16. The averages and daughter’s calves. Angus cattle generally don’t have
percentile bands are the easiest way to compare the a problem providing enough milk for their offspring so
merits of particular animals. we don’t need to worry too much about pushing this
figure. Too much milk can lead to udder problems and
Accuracy (%) Provides an indication of the reliability
of an EBV. As more performance information becomes difficulty getting back in calf, so keep it positive but
available on an animal, its progeny and relatives, the keep in mind the implications of too much milk.
accuracy of its EBVs for particular traits increases. Scrotal Size (cm) This figure tells us about the scrotal
The higher the accuracy, the less chance that the circumference of an animal at 400 days of age.
figure for each EBV will change. We measure scrotal size because there is a strong

Calving Ease Direct (%) CE Dir This tells us the positive correlation between scrotal size and fertility in
amount of calving ease we can expect from a the male and female offspring. The larger the testicles,
particular bull, relating directly to the females he is the more likely that bull will sire more fertile daughters
joined to. The calving ease figures will generally only and get more females in calf. A higher positive value
appear on the chart of a sire, but can also appear is better.
on a younger bull’s chart if there has been a lot of Days to Calving DC (Days) This tells us about female
information gathered on his relatives. A positive value fertility. It is expressed as the number of days from the
here is better. start of the joining period until subsequent calving.
A more fertile cow i.e. one that gets in calf earlier is
Calving Ease Daughters (%) CE Dtrs This tells us the
amount of calving ease we can expect from a particular obviously more beneficial in a breeding program. A
bull’s daughters. A positive value here is better. negative value here is better.
Gestation Length (Days) This figure gives us a Carcase Weight (kg) Carcase weight provides us
value relating to the number of days from the date of with an estimate of the variation in carcase weight of a
conception to the calf birth date. A shorter gestation particular animal’s progeny at slaughter (this figure is
length is better as it gives more time for the cow to adjusted to 750 days of age). The higher the number
get back into calf and there is less chance of the the better.
calf getting too big in the uterus and increasing the Eye Muscle Area (cm2) Results from ultrasound
chances of calving difficulties. A negative value here is scanning of cattle at 15-18months of age are used to
better calculate the expected genetic differences between
animals in eye muscle area at the 12th/13th rib site, in
Birth Wt (kg) Birth weight gives us an indication of
how much the calves of a particular animal will weigh a 400kg carcase. This figure gives us a good idea of
at birth. This figure should be monitored, but be the muscling ability of the animal. The more muscling
careful not to go too low as this can cause problems an animal possesses the better. Therefore a higher
with calf mortality and calving ease down the track. positive value is better.
We must also remember that only a small percentage Rib and Rump Fat (mm) Ultrasound scanning data
of calving ease is related to birth weight. is also used to calculate these figures which estimate
the genetic differences between animals in fat depth

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