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Genestar Marbling Test - Mating Outcomes |
Mating Designs: The result of mating
different GeneSTAR bulls with various GeneSTAR cows is
shown in terms of expected progeny proportions below:
|
Sire
is |
Dam
is |
Proportion
of progeny expected to be |
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|
|
100% |
|
|
|
|
|
50% |
50% |
|
|
|
|
|
100% |
|
|
|
|
50% |
50% |
|
|
|
|
25% |
50% |
25% |
|
|
|
|
50% |
50% |
|
|
|
|
100% |
|
|
|
|
|
50% |
50% |
|
|
|
|
|
100% |
What is the effect associated
with the marker?
The test determines if an animal has zero, one
(heterozygote) or two copies (homozygote)
of the favorable marker allele.
Research conducted by CSIRO has revealed that the
effect of the allele is largely recessive.
The
heterozygotes are closer in marbling performance to animals with no copies
than homozygotes.
Thus
the major benefit of the effect is obtained through increasing the frequency
of homozygote animals.
These
results are illustrated in the graphs shown below reproduced by permission of
CSIRO and MLA.
Figure 2:
Effect of 0, 1 or 2 copies of the GeneStar Marbling allele in Angus (A),
Shorthorn (S) and
a
mixed group of breeds (M) on average marbling score following 200 days on
feed.
|
Extract
copy from Genestar Website |
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