Another mode of examination through the flank is by touch. The palm of the hand is pressed strongly inward, about 8 inches in front of the stifle and a little below, several times in succession, and is then brought to rest with the pressure maintained. Presently there are felt distinct and characteristic movements of the fetus, which has been disturbed and roused to action. Another mode is to press the closed fist strongly inward in the same situation and hold it so, forming a deep indentation in the abdominal wall. Presently the knuckles are felt to be struck by a solid body, which is no other than the fetus that has been displaced to the left by the push of the hand, and now floats back in its liquid covering (amniotic fluid; see [Pl. XII]) downward and to the right.
Of all the modes of examination by touch, that done through the rectum gives the earliest satisfactory indications. The hand and arm, well oiled, are introduced, and the excrement having been removed if necessary, the palm of the hand is turned downward and the floor of the pelvis carefully examined. There will be felt in the median line the pear-shaped outline of the bladder, more or less full, rounded or tense, according to the quantity of urine it contains. Between this and the hand will be felt a soft, somewhat rounded tubular body, which divides in front into two smaller tubes or branches, extending to the right and left into the abdomen. This is the womb, which in its virgin, or unimpregnated, condition is of nearly uniform size from before backward, the main part or body being from 1½ to 2 inches across, and the two anterior branches or horns being individually little over an inch wide. Immediately after conception the body and one of the horns begin to enlarge, the vacant horn remaining disproportionately small, and the enlargement will be most marked at one point, where a solid, rounded mass indicates the presence of the growing embryo. In case of twins, both horns are enlarged. At a more advanced stage, when the embryo begins to assume the form of the future animal, the rounded form gives place to a more or less irregular nodular mass, while later still the head, limbs, and body of the fetus may be distinctly made out. The chief source of fallacy is found in the very pendent abdomen of certain cows, into which in advanced gestation the fetus has dropped so low that it can not be felt by the hand in the rectum. The absence of the distinct outline of the vacant womb, however, and the clear indications obtained on external examination through the right flank will serve to prevent any mistake. The fetus may still be felt through the rectum if the abdomen is raised by 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, which are best heard in the absence of rumbling, are about 120 a minute and easily distinguished from any bowel sounds by their perfect regularity.
DURATION OF PREGNANCY.
From extended statistics it is found that the average duration of pregnancy in the cow 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 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 shortened, the question of profit must still hold sway, and, when disqualified, 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 regards both exercise and feed, 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 ditches or fences, subjecting to blows with the horns of pugnacious cattle, driving on icy or otherwise slippery ground, carrying in railroad cars, kicking by vicious attendants, and fastening or throwing down for operations. The diet should be good, not of a kind to fatten, but with a generous quantity of nitrogenous constituents which will favor both the yield of milk and the nourishment of the fetus. Aliments like wheat bran, middlings, etc., which are rich in lime and phosphates, can be used to advantage, as there is a constant drain of earthy salts for the building of the body of the calf, and thereby the danger of undue concentration of the urine is lessened. Hard, innutritious, and indigestible aliments, musty grain or hay, partially ripened rye grass, millet, Hungarian grass, vetches, peas, or maize are objectionable, as they are liable to cause indigestion or even paralysis; and corn or hay affected by smut or ergot, or that has been spoiled by wet, overripened, and rendered fibrous and innutritious, is equally objectionable. In the main the feed should be laxative, as costiveness and straining are liable to cause abortion. Roots and green feed that have been frosted are objectionable, as being liable to cause indigestion, though in their fresh condition most wholesome and desirable. Ice-cold water should be avoided, as calculated to check the flow of milk, to derange digestion, and to cause abortion. A good temperature for the drink of the dairy cow is 55° F.
In the case of plethoric and heavy-milking cows of mature age and in the prime of life, the hitherto liberal diet must be changed at the last week for the scantiest possible fare, and the bowels must be kept open by laxatives, if need be, if the owner would avoid milk fever. Her stall should not incline downward from shoulder to croup, lest the pressure of the abdominal organs should produce protrusion or abortion. She should be kept aloof from all causes of acute diseases, and all existing diseases should be remedied speedily and with as little excitement of the abdominal organs as possible. Strong purgatives and diuretics are to be especially avoided, unless it is in the very last days of gestation in very plethoric cows.