120 THE BREEDING OF ANIMALS 



ticularly of the reproductive organs, which is to be re- 

 garded as favorable for conception. 



The importation of animals from foreign countries 

 often results in temporary barrenness. This condition 

 seldom or never becomes permanent. 



116. Sterility from fatty degeneration. The main- 

 taining of animals in an excessively fat condition for a 

 long period of time will eventually result in fatty degener- 

 ation of the tissues. When this condition attacks the 

 ovaries, it frequently causes permanent sterility. Cer- 

 tain foods are believed to hasten fatty degeneration of the 

 reproductive tissues. Tanner 1 holds that " this fatty 

 degeneration of the ovaries has been traced to the use of 

 foods rich in sugar. I have reason to believe that the 

 action of sugar in its various forms is most important 

 in its influence upon the generative system, and I think 

 there is just cause for considering that any animal may 

 by its use be rendered incompetent for propagating its 

 species." 



117. Sterility caused by abortion. Among the impor- 

 tant causes of infertility among the domestic animals 

 probably none is responsible for so many failures to 

 produce living offspring as abortion. Two kinds of 

 abortion are recognized, non-contagious and contagious. 

 Non-contagious abortion may result from a variety of 

 causes closely associated with the environment of the 

 animal. Law 2 gives a number of the more important 

 causes of abortion in the mare. " The mare may abort 

 by reason of almost any cause that very profoundly dis- 



1 Tanner, "The Reproductive Powers of the Domestic Ani- 

 mals," Journal of the Royal Agricultural Society, vol. 1, 1865, 

 p. 267. 



2 Law, "Diseases of the Horse," U. S. Department of Agri- 

 culture, 1903. 



