106 ■ FISH FODDER FOR CATTLE. 



FISH FODDER FOR CATTLE. 

 By Dr Andrew P. Aitken, Chemist to the Society. 



To feed a cow upon fish may seem at the first mention of it 

 a very absurd, as it is a very unnatural, proceeding ; but the 

 absurdity vanishes when we inquire, in an unprejudiced way, 

 into the nature of food and the transformations it undergoes in 

 the animal body. Nothing is more evident than that cattle are 

 intended to be fed upon a vegetable diet. Their deficient 

 incisors and large grinding molars, their huge paunch and com- 

 plicated digestive apparatus, their power of ruminating, and 

 their very long alimentary canal, all indicate that they are 

 adapted for utilising a bulky, somewhat brittle, difficultly di- 

 gestible, and perhaps in great measure indigestible, kind of food, 

 such as grass, hay, and the like. But although they are pro- 

 vided with the means of extracting nourishment from what may 

 be called very refractory materials, that does not prevent their 

 being able to make good use of easily digestible and concen- 

 trated food if they can get it. Whatever be the nature of the 

 food an animal eats, whether it be a rough, poor, vegetable sub- 

 stance, such as wheat straw, or a rich one, such as young clover 

 or oilcake, or whether it be an animal substance, such as milk or 

 flesh, it owes its feeding properties to the presence of nutritive 

 constituents, classified under the head of albuminoids, fat, and 

 carbohydrates, and of course a certain amount of essential 

 mineral salts, which we may overlook for the present. The 

 business of digestion is to convert these substances- into albu- 

 men, fat, and sugar, and these are either consumed in carrying 

 on the functions of life, or are stored up in the tissues of the 

 animal. The albumen, fat, and sugar extracted from a veget- 

 able-diet does not differ from that extracted from an animal 

 diet. These substances are extracted more easily from one kind 

 of fodder, and with more difficulty from another; but the 

 mechanism of the digestive apparatus of different animals is 

 modified to suit the food which is natural to them. It is neces- 

 sary for a ruminant, with its capacious alimentary system, that 

 it should daily consume an amount of fodder sufficient to fill 

 its stomach, and thus enable the mechanical operations of 

 digestion to go on in a healthy manner ; but along with the 

 rough fodder required for that pur]3ose, some more concentrated 

 fodder must be given if the animal is to progress raj)idly in con- 

 dition. Whether that concentrated fodder is derived from 

 animal or vegetable sources is of no importance, so long as it is 

 wholesome and nutritious, and we must not put too narrow an 

 interpretation upon the definition that an animal is herbivorous 

 or carnivorous. The dog is by nature a carnivorous animal, but 



