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,’ commercial rice bran may contain 
as low as 4 per cent of protein and 2 per cent of fat, 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 20 per cent fiber. 
Test for Rice 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 
into the 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, e.g., cane molasses (p. 192). 
Pure rice bran and rice polish are both 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.* 
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., b. 330. 
