264 Pork Production 



proteins from vegetable sources. Another reason why 

 tankage is highly efficient for balancing corn is because 

 of its extreme richness in ash or bone-building material. 

 Furthermore, a large part of this ash is calcium or lime, 

 which is present in very meager amounts in corn. Tank- 

 age is a mild laxative when fed in small amounts and tends 

 to promote a healthful condition generally. 



LINSEED-OIL MEAL 



Linseed-oil meal is the ground residue after the oil 

 has been extracted from flaxseed. There are two methods 

 of removing this oil, known as the old and the new process. 

 Woll 1 describes the methods of manufacture as follows : 

 "By the former method the cleaned and ground seeds 

 are placed in large linen bags and subjected to heavy 

 pressure until the residue forms cakes about one inch 

 thick and about 13 by 32 inches. The cakes are broken 

 into small pieces or ground to a fine meal, usually the 

 latter, which is generally sold as old-process linseed-oil 

 meal, or simply oil meal. In the new process of manu- 

 facture the flaxseed is ground, and heated to about 160 F., 

 and is then placed in large percolators which hold about 

 1000 bushels or more. The seed is treated repeatedly 

 with naphtha until practically all the oil is dissolved. 

 Live steam is then introduced into the percolators and 

 the naphtha gradually driven out of the mass. The meal 

 is transferred to steam-heated driers, and, when dried, 

 elevated to the meal bins and sacked." 



There is little difference in the value of these feeds 

 suggested by the figures given in the composition table. 

 The chief difference is that the old-process meal contains 



1 "Productive Feeding of Farm Animals." 



