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Muscle Selection Research Reveals Profit |
Edited by: Peter Speers
Selecting a Herd for Muscling can generate $150 per head higher returns from
Higher Yielding Carcases
with the bonuses of:
* Lighter Birth Weight Calves
* No increase in Calving Difficulty
* No change in Weight Gains
* Leaner Carcases
* Smaller Frame Scores
Importantly,
to substantially change a herd’s muscling levels,
the female herd
must also be selected for muscularity.
Selection using Live Muscle Scoring (LMS) has been shown in a NSW Agriculture research project to dramatically increase the level of muscling in a beef herd, with potential to boost sale progeny by $150 per head. The research also demonstrated that heavier muscled cattle are likely to have lighter birth weights with no increase in calving problems. The heavier muscled cattle in this research program also had similar weight gains and at the same age and weight were smaller framed and leaner.
SUMMARY
of FINDINGS
*
Increasing muscling via purebreeding will be slow due to moderate
heritability and a small variation
in the population.
*
For rapid progress, utilize between breed variation in muscling.
*
Using highly muscled bulls does not necessarily increase calving problems or
decrease growth rate.
*
The change in the distribution of progeny LMS (e.g. low muscled) is more
significant than the actual
quantitative change in
muscling.
*
Increase in height will decrease LMS unless selection is applied for muscling.
*
Future selection for maturity pattern should consider both frame score and LMS.
*
Selection for muscling must also be applied to the Female herd for significant
improvement
to occur.
Editor's Note:
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Simmental bulls, with their strong muscling attributes, offer crossbreeders the opportunity to boost progeny muscling levels in addition to increasing progeny weight gains. Also, by retaining Sim-infused females for breeding, their improved muscling will further contribute to improved progeny muscling levels and higher prices. Their superior milking ability ensures calves can fully express their superior weight gaining genetics, leading to heavier, well finished, highly muscled calves. |
Results
Outlined at Field Day
The
effects of selection for increased muscling on beef herd production and
profitability traits were outlined at a field day on 28th June 2002
at NSW Agriculture’s Elizabeth Macarthur Agriculture Institute at Menangle,
near Camden. The research project, now in its 10th year and led by
The Department’s technical specialist (beef grazing systems), Mr Bill
McKiernan, has studied a range of effects in divergent selection lines of
Angus cross Angus/Herefords.
The
project has used only one selection criteria – live muscle score (LMS) –
in a line of cattle selected for high muscle (HM)
and in a line selected for low muscle (LM). Preliminary results were
released at the field day.
Mr
McKiernan said that the divergence in muscle score in the steers from the two
selection lines has so far spread to almost 2 full muscle scores. In economic
terms based on recent market reports this equates to a difference of almost
$150 per steer at the same age of turnoff. The overall economic effect of
this, plus the extra value of the cull females on whole herd profitability is
quite extraordinary.
He
also said that the research to date on the side effects of selection for
increased muscling had dispelled beliefs by some in the industry that higher
muscling may lead to reduced reproductive performance.
Indications
to date are that the HM cattle are leaner at the same age and weight, and
smaller in height or frame score than the LM cattle. The HM line produces
lighter birth weight calves with no difference in calving ease between the HM
and LM lines.
It
appears that use of Frame Scoring alone as a measure of Maturity Pattern may
be flawed. Heavier muscled cattle are likely to have a lower Frame Score for
the same Maturity Pattern as poorer muscled cattle, with 1 muscle score
equivalent to 1 Frame Score.
Thus
a 3 frame score animal with “B” muscle score could have a similar maturity
pattern to a 5 frame score, “D” muscle score animal.
While
selection to improve muscling within a purebreeding program will be slow, it
can be hastened by crossbreeding with a better muscled breed.
Importantly,
to substantially change a herd’s muscling levels, the female herd must also
be selected for muscularity.
(Simmental
Australia takes no responsibility for the accuracy of these reported results,
and
indemnifies NSW Agriculture if they are inaccurately reported).