DISEASES OF THE OX AND SHEEP. 649 



of gestation did not exceed 286 days, the number of cow-calves 

 produced was 233, and the number of bull-calves 234; while 

 from those whose period exceeded 286 days, the number of cow- 

 calves was only 90, while the number of bull-calves was 152." 

 Hence it seems to be the case that when the time of gestation of 

 a cow is longer than usual, the produce is generally a male 

 <5aH. 



Labour, although perfectly natural, may occupy some time, 

 or be rapidly effected. In the mare delivery is as a rule quick, 

 the birth of a foal rarely occupying more than a few minutes. 

 In the cow half an hour may be regarded as about the average 

 time after labour-pains have shown themselves, while in the ewe 

 it not unfrequently happens that several hours may be spent in 

 labour. 



We have now to consider briefly the ordinary mode of 

 delivery. As the time draws near, a discharge of thick mucus 

 may bo observed, the mammary gland becomes swollen, hot, and 

 full of colostrum (the first milk), the ligaments of the pelvis 

 give way, the cow becoming "down in her bones." The cow 

 separates herself from the herd, if in the field, and shows 

 signs of uneasiness. When delivery is at hand, the animal 

 •evinces great restlessness, lies down and rises again quickly, and 

 the labour-pains come on and gradually increase in intensity, 

 until after a time the act of bringing forth takes place. This 

 will be generally about 280 days or perhaps a few more after 

 impregnation. The cow may assume the recumbent posture. 



The symptoms denoting the approach of labour are in fact 

 restlessness, frequent change of position, lying down, quick 

 rising, straining, and so forth. 



These all indicate an excited state of the system accompanied 

 with pains of a bearing down and intermittent character. 



The amnion is first protruded and then ruptured, a watery 

 "fluid being consequently set free. Then the fore-leet of the 

 calf appear, and soon afterwards the head also shows itself, as it 

 rests upon the legs near the knees, and finally and slowly the 

 whole animal. {See Fig. 85.) The act of delivery may be said 

 to occupy in the general way about an hour. 



In giving aid, it is important to remember that advantage 

 should be taken of each labour-pain, gentle force being applied 

 by pulling the fore-legs, and, if necessary, the head also. In 



