CONCENTRATED FOODS 273 



All leguminous seeds are more or less binding in their 

 effects, and in large quantities they give rise to febrile 

 symptoms. They are chiefly useful for mixing with maize and 

 other starchy foods so as to raise the albuminoid ratio. They 

 are employed in this manner in the rations for milk cows, and, 

 to a certain extent, as a partial substitute for oats in the 

 rations of working horses. 



Oily Seeds. With the exception of linseed (flax seed) 

 these seeds are not used in their natural state for feeding cattle. 

 The high value of the oil they contain makes the price 

 prohibitive. Linseed, however, is used to a considerable 

 extent for feeding newly weaned calves. For this purpose it 

 is boiled with water and allowed to cool. The mucilaginous 

 carbohydrate which it contains swells up, forming a practically 

 homogenous mixture which sets as a jelly on cooling. This is 

 much appreciated by the young animals, and is considered one 

 of the best substitutes for milk. 



Oil Cakes. The oil is generally obtained from oily seeds 

 by subjecting them to great pressure. The compressed 

 residues are known as oil cakes. They still contain some of 

 the oil and all the other nutrients originally present in the seed. 

 In fact, the percentages of these ingredients in the cake are 

 much greater than in the whole seed ; for they are increased 

 in proportion as that of the oil is diminished. Oil cakes are, 

 therefore, very rich and valuable feeding stuffs. Originally a 

 by-product, they are now probably as great a source of profit 

 as the oil itself. They are distinguished by the name of the 

 seed from which they are produced, and English law requires 

 that they should be pure. 



The method of manufacture is much the same in all cases. 

 Briefly, it is as follows : The seed, after it has been cleaned 

 and purified by screening, is ground to a coarse meal. This 

 is slightly moistened with water, crushed under heavy rollers, 

 and then heated in a steam kettle to 100 C. Measured 

 quantities, according to the size of cake to be produced, are 

 introduced into woollen bags and placed between wooden or 

 iron moulds in the press. While the temperature remains at 

 about 50 C., pressure of about a ton to the square inch is 



T 



