160 DISEASES OF CATTLE. 



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, which are best heard in the absence of rumbling, are 

 about 120 per minute and easily distinguished from any bowel sounds 

 by their perfect regidarity. 



DURATIOX OF PREGNANCY. 



From extended statistics it is found that the average duration of 

 pregnancy in the cow is 285 days. A calf bom at the tAvo hundred 

 and fortieth day may live, and a case is reported by Dietrichs of a 

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

 the Americiin Journal of Medical Science as born on the three hun- 

 dred and thirty-sixth day. It is the general observation that in 

 the majority of prolonged pregnancies the offspring is male. Lord 

 Spencer found a j^reponderance of males between the two hundred 

 and ninetieth and the three hundredth days, but strangelj'^ enough 

 all born after the three hundredth day under his observation Avere 

 females. It might 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 stimul- 

 late the womb to contraction until A'ery 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 

 secure 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 

 notwithstanding 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 profit must still hold sway, and she must yield 

 her place to another when disqualified. 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 

 regards both exercise and food, nothing is better than a run on a 

 smooth pasture. She should be withheld from all violent excitement, 

 hunting with dogs, riding or being ridden by cows in heat, driving in 

 herd rapidly through narrow gateways, causing to jump ditdies or 

 fences, subjecting to blows with the horns of pugnacious cattle, driv- 

 ing on icy or otherwise slippery ground, carrying in railroad cars, 



