Animal Husbandry Investigations in 1917. 221 



when i year and 236 days old. She was served one-half hour 

 after the appearance of this heat by a vigorous young bull in 

 lithe- cattle yard. At this service she stood for 3 coverings of her 

 own free will manifesting no difference in behavior from other 

 normal cows. Subsequent anatomical examination showed this 

 animal to be a typical freemartin with no uterus or ovary. The 

 place of the ovary was taken by what is called the saccus vagi- 

 nales with what appear to be the homologue of the gonad inside. 

 Thi(s perverted gonad is about the size of a small pea bean. 



From these facts the following conclusions appear justi- 

 fied. (1) A typical freemartin can come in heat that to all 

 appearances is normal. (2) Heat can appear in cattle where 

 only gonads of very different appearance from that of either 

 normal sex is present. (3) The deduction appears justified 

 that the growth or release of the egg is not the cause for the 

 appearance of heat. 



Cooperative Cattle Breeding Records 



The cooperative cattle breeding project, in which about 200 

 of the leading breeders of cattle in Maine, and a few outside 

 the State, have contributed was closed in September 1917 as 

 the mass of the material collected was sufficient to satisfy the 

 objects of its collection. As previously pointed out in other 

 reports the amount of these data are very large, constituting a 

 wholly unique mass of material for the study of many of the 

 most vital problems in the physiology of reproduction in cattle. 



These large amount of data will take a considerable time to 

 analyze completely. Already some facts of considerable prac- 

 tical and scientific interest are available which it seems well to 

 place immediately in the hands of the dairymen of the State. The 

 points that will be dealt with are 5, (a), the effect of the size 

 of the breed on the weight of the calf; (b), the normal length 

 and variation of the period of gestation; (c), the change in the 

 sex ratio due to twin births; (d), the time after the appearance 

 of heat that service is most likely to cause conception to take 

 place; (e), the decline in the number of conceptions as the 

 number of necessary services increases. 



