160 DISEASES OF CATTLE. 



the rectum if the abdomen is raised b}-^ a sheet passed from side to 

 side beneath it. 



Still another sign is the beating of the fetal heart, which may be 

 heard in the latter half of pregnancy when the ear is pressed on the 

 flank in front of the right stifle or from that downward to the udder. 

 The beats, whicli are best heard in the absence of rumbling, are 

 about 120 a minute and easily distinguished from any bowel sounds 

 by their perfect regidarity. 



DURATION OF PREGNANCY. 



From extended statistics it is found that the average duration of 

 pregnancy in the €Ow is 285 days. A calf born at the two hundred 

 and fortieth day may live, and Dietrichs reported a case of a calf 

 born on the three hundred and thirty-fifth day, and another was 

 reported by the American Journal of Medical Science as having been 

 born on the three hundred and thirty-sixth day. It is the general 

 observation that in most cases of prolonged pregnancies the offspring 

 are males. Lord Spencer found a preponderance of males between 

 the two hundred and ninetieth and the three hundredth days, but 

 strangely enough all born after the three hundredth day under his 

 observation were females. It may be reasonably inferred that while 

 the prevailing tendency is to carry the males overtime, yet that the 

 smaller and comparatively much less developed female sometimes 

 fails to stimulate the womb to contraction until very far beyond the 

 regular date. 



HYGIENE OF THE PREGNANT COW. 



Among domestic animals considerations of hygiene must be made 

 subservient to profit, and therefore the first consideration is not to 

 obtain the most robust health, but such a measure of vigor and 

 stamina as is compatible with the most profitable utilization of the 

 animal. The breeding cow must carry a calf every year, and this 

 notAvithstanding that she is at the same time suckling another large, 

 growing calf. The dairy cow must breed every year, and at the same 

 time must furnish a generous flow of milk from nine to eleven 

 months yearly. If her health is lowered thereby or her life short- 

 ened, the question of jH-ofit must still hold sway, and, when dis- 

 qualified, she must yield her place to another. There are exceptions, 

 of course, but this rule generally holds. 



There are certain points, however, in which the interests of hygiene 

 may be considered. The pregnant cow should have exercise, and as 



