122 STATE BOARD OF AGRICULTURE. 



charge from the vaghia which has a peculiar odor that attracts the male and 

 enables him to distinguish between those females which are in season and 

 those which are not. It also seems to excite the amatory desires of the male, 

 which, in a great measure, accounts for male and female animals remaining 

 quietly together when not in season. 



The oestrum is intermittent and occurs at certain seasons of the year, but 

 may be induced at almost any time by bringing the sexes in contact with one 

 another a few times. The duration of the heat varies from one to fifteen 

 days; it is shortest in the cow and sheep, and longest in the bitch. 



GESTATION OR PREGNAJfCY 



Is the time during wliich the female carries her young in the womb, while it is 

 undergoing certain development. This period, like puberty, differs in different 

 species, and also in different animals of the same species. The usual time for a 

 mare to carry her young is eleven months, or say 335 days, it often being a 

 little longer when colts are born than when fillies, but the time is subject to 

 considerable variation; for instance, in one case where a record of 284 mares 

 was kept the period varied from 307 to 394 days, but the extreme limits ai'e 

 considered at from 300 to 400 days, below or beyond these being of exceedingly 

 rare occurrence. 



In the cow the period is usually estimated at nine months, or say 274 days, 



• but the record of 1062 cows at an agricultural college in- Germany gives the 



average 283 days. In the American Journal of Medical Science the result of 



observation in sixty-two cows gives the shortest period as 213, and the longest 



at 336, the average being for male calves 288, females 282. 



In sheep the usual time is five months, or say 152 days; in one instance 

 where a record of 429 was kept the period only varied 13 days. 



In swine the period is about four months, or, as some record it, three 

 months, three weeks, and three days. The bitch takes only two months or 

 sixty days. As the signs of pregnancy are of importance to those engaged in 

 stock raising, it may be well now to mention some of those which can be 

 recognized without much difficulty. About the earliest symptom taken into 

 consideration is the cessation of the heat, after which the venereal appetite 

 subsides, the animal becomes comparatively tranquil, and does not exhibit any 

 desire for the male, and in many instances the male will refuse to copulate 

 with the pregnant female. This is perhaps more noticable in the bull than in 

 most other domestic animals. Occasionally we meet with females that will 

 receive the male up to within a very short period of parturition. As a rule in 

 cattle and sheep there is a tendency to lay on fat during the early months of 

 pregnancy, and many owners take advantage of this circumstance when pre- 

 paring their animals for market. 



About the middle period of pregnancy, the means resorted to, by way of 

 telling whether an animal is in young or not, is by making an examination 

 per rectum, or per vagina. I prefer the former, for I think there is less risk 

 of causing abortion. To proceed, the animal should be standing with its 

 forequarters elevated, in order that the foetus (the creature before it is born), 

 if present, may come closer to the pelvic basin, and to bring it still more 

 within our reach, the bottom of the belly should be raised, by assistants pass- 

 ing a sack, or something of tlie sort, under it, and raising it up. The rectum 

 should be emptied of its coutents, the hand and arm well oiled, and the 

 exploration made. The fostus can generally be easily felt, indeed when 

 pressed upon it will often make a convulsive movement. 



