OIL BEARING SEEDS AND THEIR BY-PRODUCTS 177 



ized only when the meal is first fed to animals and the resulting manure 

 applied to the soil. (436) With increasing knowledge of the usefulness 

 of this feed, it is to be hoped that instead of annually exporting one- 

 fourth the cottonseed cake and meal produced to other countries, as has 

 been done, all will be fed on American farms. 



251. Cottonseed hulls. Cottonseed hulls, which contain somewhat less 

 digestible nutrients than oat straw, are extensively employed in the South 

 as roughage for cattle feeding. The hulls are low in crude protein, of 

 which but a small part is digestible. With only 0.3 Ib. of digestible crude 

 protein in 100 Ibs. the hulls have the extraordinarily wide nutritive ratio 

 of 1 :122, the widest of any common feeding stuff. Obviously they should 

 be used with feeds which are rich in protein. Fed with cottonseed meal 

 to steers by Wilson at the Tennessee Station, 24 cottonseed hulls pro- 

 duced somewhat lower gains than corn silage, 100 Ibs. of hulls replacing 

 170 Ibs. of corn silage. (773) Because of their low palatability and di- 

 gestibility, cottonseed hulls are not well suited to dairy cows, corn stover 

 having a higher feeding value. (628) 



Cottonseed hulls are usually fuzzy, due to short lint which remains on 

 the seed. Sometimes this lint is removed from the seed at the oil-mills 

 for paper making and other purposes and the hulls from such seed 

 ground, being then called cottonseed hull bran. Tho finely ground, 

 the value of the product is not appreciably greater than that of ordinary 

 hulls. 



252. Flax seed. The average production in the United States of seed 

 from the flax plant, Linum usitatissimum, from 1911 to 1920 was about 

 14,980,000 bushels of 56 Ibs., over 95 per ct. of which was grown in Min- 

 nesota, the Dakotas, and Montana. 25 The reserve building material is 

 stored in the flax seed largely as oil and pentosans, instead of as starch, 

 which most seeds carry, no starch grains being found in well-matured 

 flax seeds. On account of the high commercial value of the oil it con- 

 tains, flax seed is rarely used for feeding stock other than calves. (681, 

 683) 



The oil of the flax seed is either extracted by the "old process/ 1 thru 

 crushing and pressure, as in the production of cottonseed oil, or it is 

 dissolved out of the crushed seed with naphtha, the residue in either case 

 being variously termed linseed oil meal, Unseed meal, or simply oil meal. 

 Pure linseed meal should contain no screenings. In the United States 

 practically all the linseed oil meal has been made by the old process. 



According to Woll, 26 in the manufacture of new-process oil meal the 

 crushed and heated seed is placed in large cylinders or percolators, and 

 naphtha poured over the mass. On draining out at the bottom the naph- 

 tha carries with it the dissolved oil. After repeated extractions steam is 

 let into the percolator, and the naphtha remaining is completely driven 

 off as vapor, leaving no odor of naphtha on the residue, which is known 

 as " new-process " linseed oil meal. 



"Tenn. Bui. 104. "IT. S. Dept. Agr. Yearbook. "Wis. Bpt. 1895. 



