DAIRY, SEED IMPROVEMENT, STOCK BREEDERS' MEETINGS. 2.^7 



4. THE RELATION OE THE TIME OF SERVICE TO THE SEX 



RATIO IN CATTLE. 



One of the primary purposes for which the cooperative cattle 

 breeding record plan discussed in the preceding sections was 

 undertaken was to get comprehensive statistics to show whether 

 any definite effect on the proportion of male and female calves 

 born could be observed when service occurred at different times 

 in the heat period. Work done at the Station some years ago 

 suggested that when service occurred very early in heat there 

 was likely to be born a larger proportion of heifer calves, and 

 when service occurred very late in heat there was likely to be 

 born a larger proportion of bull calves. With the hope of get- 

 ting a very much larger amount of more precise data on this 

 point, and demonstrating whether the suggestion of the earlier 

 results was correct or not, the cattle breeding record plan was 

 inaugurated. 



A considerable mass of material on this point has accumu- 

 lated, but it is thought desirable to wait until another year's 

 records are in hand before reporting further in regard to the 

 matter. 



5. CYSTIC DEGENERATION OF THE OVARIES. 



During the past year there has been published the results of 

 the study" of an interesting case of a fairly common cause of 

 sterility in cows. A pure-bred registered Ayrshire cow, named 

 Dorothy of Orono (23010), belonging to the University of 

 Maine, produced three calves, on dates as follows : September 

 17, 1909, September 10, 1910, February 24, 1912. When 3 

 years and 327 days old Dorothy of Orono was started on an 

 official milk test of one year, which she completed with a record 

 of 1 1463 lbs. of milk, carrying 417.71 lbs. of butter fat. For 

 this record she was entered as No. 426 in the Ayrshire Ad- 

 vanced Registry. Her complete lactation record is shown in 

 Table 10. 



liPearl R. and Surface, F. M. Sex Studies, VII. On the Assumption of Male Second- 

 ary Characters by a Cow with Cystic Degeneration of the Ovaries. Me. At. ExDt 

 .«!f-.nt_ Ann Rpnf 101.=; t^r^ r,S_Rn ° ' 



Stat. Ann. Kept., 1915, pp. 65-80. 



