INHERITANCE OF WOOL-CHARACTERS IN SHEEP 385
Warwick (1931) and Warwick and Bell (1929) carried out experiments to
determine the mode of inheritance of chalky fibres. They obtained results as
shown in the following tables from Warwick (1931) :—
Chalky-facedXclalky-faced Merino sheep.
|
— |
Chalky |
Ckalky |
Total |
|
Expected (3-1) . . . . . . . . . . |
15 |
5 |
20 |
|
Actual . . . . . . . . . . |
13 |
7 |
20 |
|
Deviation . . . . . . . . . . |
—2 |
+2 |
— |
Clean-facedXchalky-faced Merino sheep.
|
— |
Chalky |
Chalky |
Total |
|
Expected (1—1) . . . . . . . . . . |
7 |
7 |
14 |
|
Actual. . . . . . . . . . |
3 |
11 |
14 |
|
Deviation . . . . . . . . . . |
—4 |
+4 |
— |
Warwick, therefore, concludes that the condition is due to dominant rather
than to recessive characters, and suggests that only one pair of dominant factors
is responsible. Rigid and continual selection against chalk-face would therefore
serve to eliminate this condition from a stock of breeding ewes, and only rams free
from it should be used.
Soft, and stiff hairs on face. Wriedt (1925) reports the results of experiments
conducted to determine the inheritance of soft and stiff hairs on the face, especially
the nose, of Rygaya sheep in Royaland, Norway, He obtained the following
results:—
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