MENDELISM IN FUR SHEEP 

 CROSSES-II 



THE ZYGOTIC CAUSE OF RED LAMBS, WHEN FUR SHEEP ARE CROSSED 

 ON LONGWOOLS OR THEIR GRADE OFFSPRING 



Russell W. Duck 

 Animal Husbandry Department, Syracuse University 



IN A PREVIOUS article, published in 

 the Journal, it was shown from 

 results obtained, that homozygous 

 Karakul sires crossed on Longwool 

 ewes gave complete dominance of 

 black fur. However, a red lamb ap- 

 peared occasionally. This red individ- 

 ual was of a different color from either 

 of the original parent phenotypes. 



In the Journal of Heredity, Vol. 

 V, No. 4, April 1914, Dr. C. C. Young 

 frequently mentions the lack of any 

 systematic breeding methods among 

 the breeders of fur sheep in their native 

 home. He states that in May 1913 he 

 imported a herd consisting of seven- 

 teen Karakuls, one four-horned, fur- 

 bearing Karachiev ram, and one 

 enormous red Kalmik, fat-rumped ram. 

 He further states as follows, "The fur- 

 riers who in their ignorance call Kara- 

 kul skins, either full bloods or grades, 

 'Persian,' 'Persian Baby Lamb,' 'Per- 

 sian Broad-tail,' or 'Astrakan' furnish 

 the opportunity for certain breeders of 

 red Persian, fat-rumped sheep, to dis- 

 pose of their stock as 'Persian Broad- 

 tails.' " 



In view of these statements it is 

 apparent that some so-called full 

 blood Karakuls may carry the red 

 factor recessively, due to crossing on 

 these red strains in their native country. 

 Unfortunately, from a scientific stand- 

 point, the red lambs produced at the 

 Dawley Farm were eliminated from the 

 flock. Their skins, in every instance, 

 were undesirable commercially, due to 

 the fact that apparently the red color 

 factor was correlated with loose, dull 

 fleece. The exact behavior with re- 

 spect to white and black fleece was, 

 therefore, not established by direct 

 crossing. However, it is unquestion- 

 ably dominant to white (longwool) and 



recessive to black (Karakul). Pure- 

 bred Longwools bred pure do not pro- 

 duce red lambs. In correspondence 

 with Longwool associations and breed- 

 ers no record could be found of a red 

 lamb produced by registered Long- 

 wools, thus showing their freedom 

 from the red color factor. On the other 

 hand. Professor R. Owen Wahl, chief in 

 charge of fur-sheep breeding work for 

 Grootfontein School of Agriculture, 

 Middleburg (Cape), South Africa, 

 recently stated they had a full-blood 

 Karakul ram in their stud that pro- 

 duced red lambs when crossed on 

 full-blood Karakul ewes. 



In 1912 Mr. F. E. Dawley, Fayette- 

 ville, N. Y., crossed full-blood Karakul 

 sires on registered Lincoln, Leicester, 

 Cheviot, Black Faced Highland and 

 Cotswold ewes; this cross produced 106 

 black lambs and one red. In 1913 using 

 the same cross. 111 were black and one 

 was red. Both reds were by the same 

 sire, but, the 1912 red was out of a 

 Leicester ewe while the 1913 red was 

 out of a Lincoln. The behavior of 

 red with respect to white, in this case, 

 can be explained when it is known that 

 the reds in question were really not true 

 red but more of a chocolate color. True 

 reds were later produced in the Fa 

 generation by another sire. 



Let (B) represent the black factor 

 and (R) the red factor, then (b) and (r) 

 show their respective absence. The 

 Karakul sire, which produced the choc- 

 olate colored lambs, is homozygous for 

 black color, but heterozygous for red 

 color. He then has the zygotic consti- 

 tution, with respect to color, of (BBRr), 

 while the ewes are (bbrr). The sire 

 forms gametes (BR) and (Br) in equal 

 ratio, the ewes form gametes (br) 

 only. 



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