84 



THE BREEDING OF ANIMALS 



known to secrete milk. The hybrid mare mule in rare 

 cases has been known to secrete milk through the excita- 

 tion of the mammary glands. In the cases observed, 

 the mammary glands have generally been stimulated 

 to secrete through the persistent suckling of some young 

 mule colt which may have been running in the same 

 pasture or lot. It is rare that the mammary glands of a 

 mare mule will develop to the point of secreting milk 

 in the absence of some such stimulation. 



The author has discovered one mare mule which has 

 secreted milk without any such stimulus. This mare 

 mule belonging to L. O. Swarner of Boonville, Missouri, 

 when first observed had been giving milk for some weeks. 

 The owner in a letter to the author says : "I have a mule 

 that has been giving milk the same as a brood mare does 

 when suckling a colt. She has been giving milk for about 

 five weeks. The mule is still giving milk, as much as a 

 quart at a time. (See Plate III, upper.) The milk is pure 

 white and streams from her udder." This mare mule 

 came in heat regularly and was bred several times but 

 failed to become pregnant. The milk was analyzed by 

 the Missouri Experiment Station. The analysis is shown 

 in the table in comparison with cow's and human milk : 



COMPOSITION OP MILK FROM MARE MULE COMPARED WITH 

 Cow's AND HUMAN MILK 



