There has been much research looking at heritability for various traits in livestock. It can be seen that most reproductive traits have low heritability (<.20), growth traits have moderate heritability (.20-.40), and carcass traits have fairly high heritability (>.40). This is not always true but is a good rule of thumb. Note that loin eye area is the second most heritable trait in sheep ( according to this study/chart).
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Table 4. Heritability Estimates for Sheep |
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Correlations |
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Trait |
h2 |
BW |
WW |
ADG |
FW |
FD |
SL |
CG |
FAT |
LEA |
|
birthweight (BW) |
.15 |
|
.34 |
|
|
|
|
|
|
|
|
90-day weight (WW) |
.25 |
.29 |
|
.53 |
.06 |
-.24 |
-.15 |
|
-.19 |
|
|
postweaning gain (ADG) |
.40 |
|
.30 |
|
.17 |
.16 |
-.20 |
|
-.19 |
|
|
grease fleece wt (FW) |
.35 |
|
.30 |
.22 |
|
|
|
|
.08 |
|
|
fiber diameter (FD) |
.40 |
|
-.01 |
.10 |
|
|
|
|
-.21 |
|
|
staple length (SL) |
.55 |
|
.01 |
-.01 |
|
|
|
|
.11 |
|
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carcass grade (CG) |
.20 |
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|
|
|
|
|
|
.31 |
-.28 |
|
fat thickness (FAT) |
.30 |
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|
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loin eye area (LEA) |
.50 |
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|
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ewe fertility |
.05 |
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|
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prolificacy |
.10 |
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scrotal circumference |
.35 |
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age at puberty |
.25 |
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lamb survival |
.05 |
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ewe productivity |
.20 |
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preweaning gain |
.20 |
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60-day weight |
.20 |
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120-day weight |
.30 |
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240-day weight |
.40 |
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carcass weight |
.35 |
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dressing % |
.10 |
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clean fleece weight |
.25 |
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crimp |
.45 |
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color |
.45 |
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aphenotypic correlations below diagonal, genetic correlations above diagonal Sheep Industry Develop Program Inc. 1987. Sheep Production Handbook. Lasley, J.F. 1978. Genetics of Livestock Improvement. Prentice-Hall. |
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