34 BOVINE OBSTETBICS 



manifest ; oestrum in the cow repeats itself every three to four 

 weeks. Should oestrum not set in, conception is surmised. 



In many cases this holds true, although some cows rut 

 quietly and are overlooked. Besides, it happens at times 

 that pregnant cows bull three or four weeks after fecundation, 

 take the male, and the cow as a consequence is three or four 

 weeks too early, or, rather, the attendant overlooks the fact 

 that she conceived at the first coition. 



During the first months of pregnancy the behavior of the 

 cow changes some ; she avoids galloping, jumping ditches and 

 fighting with other cows. Some observers noticed that certain 

 cows develop peculiar notions, viz., eat dirt, gnaw stones, 

 drink a great deal of water, etc. Some cows when pregnant 

 become fat. This symptom is often quite a positive one to the 

 owner or attendant. 



An increase in the quantity of blood takes place in 

 the second half of gestation as a consequence of the increased 

 placental circulation. As a further consequence, the heart 

 undergoes greater efforts to supply the parts with blood, 

 the heart becomes larger, active dilatation — hypertrophy — 

 takes place. This hypertrophy of the heart does not dis- 

 appear soon after parturition, but continues for quite a while, 

 to become permanent if immediate fecundation occurs. There- 

 fore, hypertrophy of the heart is frequently seen in old cows 

 who calved yearly. 



It is well known that the horns grow less during preg- 

 nancy than otherwise. This alternating increase and decrease 

 in the production of horn is recognized by ring formation 

 of the horns. The number of rings, therefore, give an ap- 

 proximate idea how many periods of pregnancy or how many 

 calves the cow had. An unusually large space between two 

 rings indicates that the periodical yearly pregnancy was 

 missed. Of course one must remember that an alternating 

 rich and poor diet, when extending over a period of about 

 six months, influences the growth of horn similarly. 



The changed position of the gravid uterus causes a 

 dilatation of the right lower region of the belly ; it becomes 



