VARIOUS FACTORY BY-PRODUCTS 187 



In addition to the preceding by-products, a feed called " com- 

 mercial rice bran " is obtained and sold in the South. This is a 

 mixture of the pure bran with varying amounts of ground hulls, 

 the quantity of the latter being sometimes as high as 50 per cent. 

 According to the Texas station, 7 commercial rice bran may contain 

 as low as 4 per cent of protein and 2 per cent of fait, and as high as 

 50 per cent of fiber. An addition of rice hulls decreases the feed-, 

 ing value of bran in proportion to the amount of hulls added. 

 Adulteration of rice bran with hulls or mineral matter has been 

 largely practised by southern mills, and has brought the feed into 

 disrepute. In view of the danger of such adulteration, rice bran 

 should be purchased only of reputable dealers and on guarantees of 

 valuable components and maximum fiber content. It should con- 

 tain not less than 10 per cent protein and 6 per cent fat, and not 

 more than 15 per cent fiber. 



Test for Rioe Hulls. Pure rice bran and rice meal contain considerable 

 fat and are not moistened if placed on the surface of water. When the test 

 is made with rice bran or meal adulterated with hulls, these will soon sink 

 to the bottom when stirred in a tumbler of water. 



Rice polish is a highly digestible starchy feed which is used as a 

 feed for pigs, dairy cows, fattening steers, horses, and mules; its 

 high price often makes it more expensive under southern conditions 

 than, eg., cane molasses (p. 192). 



Pure rice bran and rice polish are botoh valuable feeds which 

 compare favorably with corn meal in feeding value and may be 

 fed under similar conditions. At the Louisiana station rice bran 

 was used successfully for one-half of the concentrates in rations for 

 horses and mules, and it is also a good cow feed, if fed with high- 

 protein concentrates and before turning rancid. 8 



The rice feeds will not keep long before they turn rancid on 

 account of the unstable character of the oil and the high oil con- 

 tent of these feeds. Rancid rice feeds are not palatable to livestock. 



QUESTIONS 



1. Describe the method of manufacture by which flour-mill feeds are obtained 



as by-products. 



2. What are the differences in composition and relative feeding value of 



wheat, wheat bran, wheat middlings, and red-dog flour? 



3. What are the common adulterations of wheat feeds, if any? 



4. Describe the by-products obtained in the manufacture of cereal feeds, 



barley, rye and buckwheat flour. 



5. Describe (a) the corn by-products; (6) the rice by-products. 



6. Why are rice hulls a dangerous material to be used for feeding farm 



animals ? 



7 Bulletin 73. 8 North Carolina Bulletin 169 ; U. S. Dept. Agr. Bui. 330. 



