MANUAL OJb' CATriiE-FEEDIKG. 845 



§4 Oil Seeds akd Oil Cake. 



Oil Seeds.— The seeds of certain plants, of wliich the 

 most common are flax, rape (or coka), and cotton, contain 

 large quantities of oil — flax containing 30-40 per cent., 

 rape 35-45 per cent., and cotton about 30 per cent. — and 

 are commercial sources of oil. These seeds are also rich 

 in albuminoids, but they are not often used as fodder on 

 account of their high price. Flax, however, is sometimes 

 gatheied when still unripe, in order to obtain a better 

 quality of tibre, and in that case the seeds are compara- 

 tively poor in oil, and tlieir price is so much lower that it 

 would doubtless often be advantageous to use them for 

 feeding. A fodder for young animals, for milk, or for 

 fattening, if deflcient in fat, can be essentially improved 

 by such an addition, provided that the quantity of fat 

 is not made too great. Cxenerally, when it is desired to 

 add fat to a ration, it can be effected to better advantage 

 in this way than by the addition of pure oil. It must, 

 however, bo borne in mind that these seeds contain also 

 largo quantities of protein. 



Digestibility. — No direct experiments have yet been 

 made on the digestibility of oil seeds. It may, however, 

 be assumed, until we have better data, to be the same as 

 that of the corresponding kinds of oil cake. 



Oil Cake. — The high price of oil seeds prevents their 

 general use as a fodder. They are chiefly applied to the 

 production of oil, and only tlie residue from this manufac- 

 ture is used for feeding purposes. 



The oil is generally obtained by subjecting the seeds to 

 liydraulic prcBsure, by which a large part of the oil is 

 forced out, while mobt of the albuminoids remain behind. 

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