162 



CANADIAN FARM YEAR BOOK. 



Principles and Practices in Breeding. 



Determination of Sex. 



More than five ihundred Itlieories 

 exist on this subject. Under the 

 theory of evolution any theory may 

 prolbably oome true haJsf the time. 

 Theory of male and female testicles 

 dis.proved by the fact ithat .stallioms 

 with ibut one testicle sire, both male 

 and female. Same tlheory applied to 

 females disproved on similar grounds. 

 Theory of strong personality disprov- 

 ed by the fact that sires are generally 

 better ibred than dams, yet do not give 

 a preponderance of male foals. That 

 service early in heat produces male 

 (some say female) disproved because 

 in nature females are served early in 

 their season. 



It is noticeable that nearly every 

 theory on the aetermination of sex con- 

 tains some trace of male superiority. 



It would sef-m, then, that there are 

 various circumstances that appear to 



influence the sex of offspring. These 

 seem in some cases to be connected 

 with nulution and in others with the 

 inherent nature of the germ. The 

 present knowledge is insufficient to 

 solve the problem of sex differentia- 

 tion, but it is safe to say that none of 

 the traditional facts are warranted iby 

 the known facts.— "Davenport." 



Grading. 



By "grading" is meant the mating 

 of a common or relatively unimproved 

 parent with one that is more highly 

 improved, that is, a "pure ibred." The 

 mating might be made either way, 'but 

 in practice th^? male is taken for the 

 pure-bred parent for economic rea- 

 sons. One pure-bred bull with a Iherd 

 of twenty cows can give all the calves 

 in the herd a pure^bred sire (that is. 

 make them half bloods), whereas il 

 the making of half ibloods were at- 



Daisy Dean by Dunure Baron, Champion Heavy Draft Canadian National, 1915. 



