MENDELISM IN FUR SHEEP CROSSES 



Russell W. Duck 

 Departryient of Animal Husbandry, Syracuse University 



SOME interesting results have been 

 obtained from crossing Karakul 

 rams on long-wool and Cheviot 

 ewes. Work along this line by F. E. 

 Dawley, of Fayetteville, N. Y., shows 

 the complete dominance of Karakul 

 fleece, provided the Karakul cross is 

 homozygous, for the color and fur 

 bearing factor. The work also shows 

 the practical value of a knowledge of 

 Mendel's first law. 



Karakul lambs at birth arc black in 

 color with an occasional white spot on 

 the head or tail, the ringlets of fur 

 should be of a bright luster and tight 

 curl. Density, curl, luster, pattern and 

 color are the factors which determine 

 merit in a Karakul skin, known com- 

 mercially as Persian Lamb. The beauty 

 of pattern formed by the irregular 

 arrangement of the curls, and the fine- 

 ness and softness of the coat add 

 much to its value. The desired condi- 

 tion of the skin of the lamb soon disap- 

 pears as it grows older. When only 

 twent\-four to forty-eight hours old 

 the curls begin to loosen, and the fleece 

 increases in length ; as the lamb nears 

 six months of age the fleece gradually 

 changes to dark gray wool, very long 

 and open in character. 



Da\enport found black wool reces- 

 sive to white in sheep. He has shown 

 that black crossed on black gives only 

 black, and that black outcropping in 

 white sheep is simj)le recessiv'e segrega- 

 tion. But, in the Karakul cross on 

 white wool, the white wool factor be- 



haves quite differently, it is unmistak- 

 ably recessive to black. 



In 1912 Mr. Dawley made some 

 crosses to determine the inheritance of 

 coat color and fur bearing qualities 

 of Karakuls when crossed on other 

 breeds. Two large type Karakul rams, 

 forty Lincoln, twenty Leicester, twelve 

 Cheviot, ten Black Faced Highland 

 and ten Cotswold ewes were used in the 

 first cross. The same ewes were bred 

 to the same rams again in 1913. The 

 table at the bottom of this page shows 

 the results obtained. 



Out of ninety-two ewes and two 

 years' lamb crop all the lambs except 

 two were black. One red lamb was 

 dropped in 1912 by a Leicester ewe and 

 another was yeaned in 1913 by a Lin- 

 coln ewe. The production of an occa- 

 sional red is apparently not associated 

 with any particular breed, and might 

 be explained by the introduction of an 

 extension factor, which is of infrequent 

 occurrence. The dominance of black 

 color was duplicated by three other 

 characters, curl, density and luster, 

 which proved dominant to straight, 

 long, dull wool. The skins of the Fi 

 lambs were decidedly of the fur type. 

 From the illustration it will be noted 

 that the skin from an F^i lamb was 

 curled and lustrous, closely approach- 

 ing the desired Karakul t>'pe (Persian 

 Lamb). 



In 1914 and 1915 the F„ black 

 ewes from the first cross were bred 

 back to an imported Karakul ram 



Karakul Rams Crossed with Other Breeds. 

 Parent Offspring 



410 



