Page 6 - Hemingford 2021 ebook

EBVs

We feel this is a vital tool for us as Stud breeders. It is important to remember that
they are still only an estimate of some productive traits which are relatively easy
to measure, based on the amount of information available at the time. As Stud
breeders we see how animals EBV’s change from year to year. Even on proven high
accuracy animals there can be large movements up or down as more information
is collected. Out of the bulls you could for example expect a third of the bulls actual
breeding values to be significantly different to their EBV’s. We therefore recommend
that EBV’s be used as a guide along with the other information provided, if you
require assistance, please ask.
Your breeding objective should relate to your vision of likely future market demands
in at least 2-4 years time. That is when the results of your current breeding decisions
will be realised. An important principle to remember is that for maximum market
versatility it is important to avoid extremes in any trait.
Accuracy – Accuracy (%) is presented with every EBV and gives an indication of the
amount of information that has been used in the calculation of that EBV. Accuracy
below 75% should be considered low.
How to use EBVs - The first step is to decide which characteristics are important in
your breeding program, and then select the EBVs which fit the bill for your herd.
Birth Weight EBV (kg) – based on the measured birth weight of animals, adjusted for
dam age. The lower the EBV the lighter the calves are expected at birth.
200-day Growth EBV (kg) – this EBV gives an estimation of the animal’s genetic
merit for a 200-day growth calculated independently of the maternal milk effect.
Important if a bull is used as a terminal sire for vealer production.
400-day Weight EBV (kg) – this EBV gives us an estimation of the animal’s yearling
weight potential. Combined with the carcass EBVs this is the best indicator of growth
for early maturing young cattle.
600-day Weight EBV (kg) – this EBV is an indicator of the animal’s genetic potential for
growth beyond yearling age. Heavy steer and bullock producers will be interested in
this EBV, as it is the best measure of an animal’s ability to grow on to maturity.
Scrotal Size EBV – is an indicator of the Male Fertility in regards to semen quantity.
Rump Fat and Rib Fat EBVs – are in mm. Positive EBVs indicate animals which will
breed progeny fatter (or earlier finishing) than base animals.
Eye Muscle Area EBV (sq.cm) – is currently analysed on an age constant basis so that
bulls with high growth and at least average “muscling” have the highest EBVs.
Retail Beef Yield EBV (%) – indicates genetic differences between animals for retail
yield percentage in a standard 300kg carcase. Sires with larger EBVs are expected
to produce progeny with higher yielding carcases.
2021 Breed Average EBVs for 2019 Born Calves
BW Milk 200 400 600 SS EMA Rib Rump RBY IMF
+0.2 +7 +12 +24 +32 +1.1 +1.6 +0.4 +0.5 +0.0 +0.2

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