(W)4 FOOD REQUIRED DURING PREGNANCY. 



of tne animal body. Thus in regard to the same growth of bone, it ap- 

 pears that, while linseed and other oil cakes are mainly used with the 

 view of adding to the fat, some varieties are more fitted at the same time 

 to minister to the growth of bone than others are. Thus, four varieties 

 of oil-cake examined in my laborato'-y, contained respectively of earthy 

 phosphates and of other inorganic matter in 100 lbs. the following quan- 

 tities : — 



PER CENTAGE OP 



Earthy phosphates. Other inorganic matter. 



British linseed cake . . 2-86 2-86 



Dutch do. . . 2-70 2-54 



Poppy cake .... 5-22 1*24 



Dodder cake .... 6-67 3-37 



The numbers in the first column, opposite to poppy and dodder cake, 

 show that these varieties of oil-cake contained a much larger proportion 

 of the phosphates thaa the others did, and consequently that an equal 

 weight of them would yield to growing stock more of those substances 

 which are specially required to build up their increasing bones. 



§ 10. Kind and quantity of additional food required by a 

 pregnant animal. 



The food of the pregnant animal must sustain the full-grown mother, 

 and must add at the same time to the substance of her unborn young. 

 The quantity of food which is necessary to sustain the mother — if herself 

 full-grown, which is often far from being the case — varies with many 

 circumstances. 



It is said that in the stall an ox or a cow will eat one-fifth of its weight 

 of turnips in a day, or one-fiftieth of dry food, such as hay and straw. 

 With this allowance of food the animal would probably increase in 

 weight in some degree, — but according to Riedesel one-sixtieth of its 

 weight of dry hay is necessary merely to sustain it. From what we 

 have already seen of the composition of the different grasses, it is obvi- 

 ous that the quantity required will be much affected by the kind of hay 

 with which the animal is fed. 



To nourish the young calf in the womb of its mother, an additional 

 quantity of food must be given, and this quantity must be increased as 

 the state of pregnancy advances. And though the kind of additional 

 food which is given must readily supply the materials of the growing 

 oones and muscles of the foetus, yet it must contain also a larger quan- 

 tity of starch or sugar also than the mother in her ordinary slate would 

 require. This is owing to the circumstance that the mother must now 

 breathe for two animals, for herself and her young. The quantity of 

 blood is increased, more oxygen is taken in by the lungs, and more carbon 

 is given oif in the form of carbonic acid. To supply this carbon, more 

 of farinaceous or saccharine food must be eaten from the time when 

 pregnancy takes place, and it must increase as the young animal en- 

 larges in size. 



Except in the way of feeding the mother, in all respects well, I am 

 not aware that any experiments have been made with the view of spe- 

 cially affecting the condition of the future calf by the kind of food given 

 to the mother. A certain proportion of bone and muscle no doubt must 



