Mature Cow Weight Data by lindayy


Mature Cow Weight Data

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									       Wanted - Mature Cow Weight Data!
Why is mature cow weight important?

Mature cow weight affects:
    Cow herd feed maintenance costs
    Heavy steer size
    Cull cow value.

Cow herd feed maintenance costs:
Smaller or moderate Mature Cow Weight EBVs are generally more favorable for reducing
herd maintenance costs. Feeding is a major component of the cost of running a beef
operation. It is now widely accepted that the cow herd consumes about 60 - 80% of the
energy required for beef production. When feed resources are variable and often limiting,
that’s Australian agriculture!!, moderate sized cows with moderate milk are more
economically efficient as they tend to get back in calf within a normal joining period more

Producers can use Mature Cow Weight EBVs to select ‘curve-bender’ sires that are expected
to breed daughters with moderate mature weights relative to that predicted from their earlier
growth performance. With Mature Cow Weight EBVs a producer with a self-replacing herd
in a tough environment no longer has the dilemma of having to sacrifice calf growth to get
cows back in calf. Mature cow weight is highly heritable therefore by using genetic selection
the feed maintenance costs of a cow herd can be quite significantly reduced.

Heavy steer size:
Heavy steer producers may seek high Mature Cow Weight EBVs. 600 Day Weight EBVs are
a good indicator of heavy steer weights eg for grassfed Jap bullocks. However Mature Cow
Weight EBVs can at times be an even better guide. Mature Cow Weight EBVs are
particularly useful at studs where yearling bulls are sold and fewer 600 day weights are taken.

Cull cow value:
Sale of surplus females, including cull cows, can represent a significant proportion of the
income of a beef cattle breeding enterprise. Typically 30-40 % of the income of a
commercial beef breeding operation comes from the females. Increasing cow sale weights
can have a large impact on income.

Considering cow herd feed maintenance costs, heavy steer size and cull cow value can be a
balancing exercise, and the appropriate balance will differ for producers with different
environments, production systems and target markets. Mature Cow Weight EBVs help you
increase growth, while keeping mature cow weight acceptable for YOUR ENVIRONMENT
and management system.
Why is recording mature cow weight data important?

Submitting more mature cow weight data to Breedplan will increase the accuracy of Mature
Cow Weight EBVs. The self replacing Angus selection indexes place emphasis on an
animal’s Mature Cow Weight EBV, in particular the Longfed/CAAB $ Index. The genetic
progress that can be made if selecting with the aid of a selection index can be improved by
increasing the amount of data being submitted to Breedplan for the index component traits.
You might not use selection indexes, but have you considered the number of commercial
clients that use selection indexes as a tool?

Data recording

Cow weights collected at the same time as calf 200 day weights are taken (to be exact
Breedplan will include cow weights for animals that have had a calf weight recorded within
two weeks of this, where the calf is between 80 – 330 days of age) contribute to Mature Cow
Weight EBVs.

Cow fat scores using the 1 to 6 scale that is used for market descriptions are also being
collected. Fat score is not currently used in the Breedplan analysis, however that data may be
valuable for refining this trait in the future.

With some practice fat scoring isn’t a hard skill to develop. It is differences between
individuals within the mob that are required for the data to be analysed. Fat score
descriptions are included below. In some states Department of Primary Industries Beef
Officers offer courses that include fat scoring.

How does Breedplan handle mature cow weight data?

Breedplan can analyse up to 4 mature weights for each cow. Cow weights are sliced into
analysis groups on an age basis. Weights from cows in a 365 day ‘slice’ are age adjusted and
also adjusted according to their age at first calving.

Further information is contained in a tip sheet titled “Understanding Mature Cow Weight
EBVs”. This is available from the technical area of the BREEDPLAN website
                                   Angular and narrow. Hips, pins,
                                   backbone and ribs very prominent.
                                   No filling in the brisket. Cut up

                                   Hips, pins, backbone and ribs very
                                   obvious but not prominent. Flank
                                   still cut up. A little filling in the

                                   Moderately rounded appearance.
                                   Hips, pins, backbone and ribs
                                   lightly covered. Flank filled to
                                   about stifle joint. More filling in

                                   Smooth covering over hips, pins,
                                   backbone and ribs to give well
                                   rounded appearance, particularly
                                   near tail head. Flank filled to
                                   below stifle joint. Brisket full.

                                   Heavy fat covering, starting to be
                                   lumpy over hips, pins, backbone
                                   and ribs. Pronounced fat deposits
                                   near tail head. Distended brisket.

                                   Very heavy and lumpy covering
                                   over hips, pins, backbone and ribs.
                                   Very pronounced (‘boxing gloves’)
                                   near tail head. Very distended

Figure 1. Fat score descriptions

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