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A STUDY OF SOME FACTORS INFLUENCING FERTILITY 

 AND STERILITY IN THE BULL 



HERBERT L. OILMAN" 

 Veterinary Experiment Station, Cornell University 



Normal reproduction is the fundamental foundation upon which 

 the entire cattle industry rests. For this reason, any factor 

 capable of interfering with it is a detriment to the industiy, and 

 a matter of prime importance to the breeder and the veterinarian. 

 With the relative increase in number and value of cattle, an.l the 

 fact that the profession is depending more and more on this in- 

 dustry for a livelihood, these problems are assuming greatei- im- 

 portance. The part plaj^ed by the bull has been emphasized 

 entirely too little, with the result that, as in human medicine, 

 many fail to appreciate the effects of sterility or lowered fertility 

 in the male. The part played by the sire in the spread of genital 

 infections, though discussed frequently, has received little sys- 

 tematic investigation. 



The bull miLst be regarded as at least half the herd, not only 

 from the standpoint of the characters he imprints upon his prog- 

 eny, but because of his relation to the reproductive efficiency in 

 the herd. It seems quite probable that he does disseminate during 

 copulation, infection associated \\i\h. the genital organs, with tlie 

 result that the bull is a very important factor in a study of the 

 subject. Too frequently, his ability to copulate in an apparently 

 normal manner, is taken as a standard of fertility. Gross changes 

 in his genitalia, or the absence of spermatozoa from the semen 

 are given due consideration, while other more ol^seure al)nor- 

 malities are not looked for nor regarded in their proper light. 

 Neither fertility nor sterility are always absolute, but the terms 

 should be used relatively inasmuch as we may have all degrees of 

 infertility or impotency. All Too frequently we foi'get the many 

 delicate and intricate mechanisms involved in ihe reproductive 

 process, with the result that many phases of the problem are neg- 

 lected or disregarded. The genital organs woi'k as a unit, each 

 part of which must function in perfect accord with the others to 

 the end that full fertility may result. The physiological factors 

 involved in the formation of the semen are too little understood, 

 or at best, our knowledge regarding them is more or less hazy. 



The purposes of the present work have been: (1) to summarize 

 the work so far done on the subject. (2) to review brietly the 

 known facts throwing light on the anatomy and physiology of the 

 male genital organs, (3) to carry out systematic studies upon the 

 pathology and bacteriology of the genital tract of the bull, and 

 (4) to ascertain if possible whether the ])ull is a disseminator of 

 those infection!^- which interfere with reproduction in the female. 



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