PRACTICAL PAPERS—ABORTION IN COWS. 
267 
lions, 939, or 71 per cent., occur during the last three months 
of utero-gestatioD, at the time the foetus must be consid¬ 
ered as making the greatest demand upon the dam for 
its nutrition; and yet, the reports of 1867 indicate a habit of 
milking cows to as late a period of pregnancy as they will 
give milk. The expressions not infrequently occured in reply 
to the question : What month of pregnancy are the cows 
dried off from milking ? “ As long as it will pay.” “ I milk 
for a pint.” “As long as possible.” And in but few 
instances were farmers able to give reliable answers as to the 
exact period of pregnancy at which any individual cows were 
dried off. Further evidence on this point would be desirable, 
but the report of every inspector, derived from the general 
statements of farmers, has been, that the habit almost univer¬ 
sally exists of milking the cows to the last paying drop. 
Besides the arrest of development from inanition, thus 
brought about, the persistent dragging at the mammary 
gland for milk during the latter months of pregnancy, is a 
source of irritation to the uterus, by reason of the intimate 
physiological connection between these organs, and tends 
very materially to excite contractions in the uterus. 
That irritation of this kind to the mammary gland in the 
pregnant human female will occasion contractions in the uterus, 
and abortion, is well known to, and practiced by physicians 
when that object is to be attained. And if, in the domestic 
cow, a liability to abortion by too early breeding is established, 
and a tendency to arrest the foetal development endangered 
by inanition, it is not improbable that so constant an irritation 
as this will account for many cases of abortion. 
The rule in the human female is very positive against the 
two processes of lactation and pregnancy going on, for a length 
of time, together, and its continuned violation is there followed 
by directly the consequences here complained of in the 
domestic cow. If, during lactation, pregnancy occurs, the 
former process must be stopped, or the mother is liable to a 
miscarriage ; or vice versa^ if lactation is stopped, the phenom¬ 
enon of ovulation, theretofore in abeyance, now begins again. 
