Flaxseed is used only to a limited extent for feeding purposes, viz., mostly as a calf feed, its high price being rather prohibitive for feeding to other farm animals. It is always ground for calf feeding and mixed with boiling hot water in the proportion of a pound of meal to a gallon of water. The jelly-like liquid thus formed has a laxative effect and forms a highly-prized component of calf rations. It is generally fed mixed with standard, easilydigested concentrates, as wheat middlings, ground oats, barley, etc. (p. 221). Flaxseed contains about 22 per cent protein, 33 per cent fat (oil), and 7 per cent fiber; it has a high digestibility, containing over 20 per cent digestible protein, 17 per cent digestible nitrogenfree extract, and 29 per cent digestible fat; owing to the large content of digestible fat, its nutritive ratio is considerably wider than that of linseed meal, viz., 1:4.0 (p. 197).

Cotton Seed.—Only relatively small amounts of cotton seed are now fed to stock on account of the value of the seed for the manufacture of cotton-seed oil. Formerly the seed was used quite generally throughout the South as a feed for farm animals. It is fed either raw, roasted, steamed, or boiled. The composition of the cotton seed is, on the average, as follows:

It contains about 11 per cent of digestible protein, 33 per cent digestible carbohydrates, and 18 per cent digestible fat. Cotton seed possesses a high feeding value, especially as a cattle feed, but has sometimes proved injurious to stock on account of the lint and the dust that it collects. It has also a decided laxative effect when fed in large amounts, on account of the high per cent of oil that it contains. The main reason for its present limited used as a stock feed is, however, that the seed can generally be sold for a good price at the oil mills, or exchanged for cottonseed meal at the rate of 800 pounds per ton of seed. Direct experiments with fattening steers and dairy cows at Southern experiment stations have shown that it requires approximately 2 pounds of cotton seed to equal 1 pound of cottonseed meal in feeding value. Boiled or roasted cotton seed has been found to produce larger gains and to be more palatable and less laxative than raw seed, but the gains made are more expensive owing to the cost of preparing the seed. Moldy or heated seed should never be used for feeding farm animals. It is only under exceptional conditions that cotton seed is now fed to farm stock, having been largely replaced by cottonseed meal for this purpose. 13

66

66

436, “

66

References: Montgomery, “Productive Farm Crops,” Philadelphia, 1918. Farmers' Bulletin 16, Leguminous Plants for Green Manuring and Feeding," 1894. 18, “Forage Plants for the South,” 1894. 102, “ Southern Forage Plants," 1899. 300, Some Important Grasses and Forage Plants for the Gulf Coast Region,” 1907. 331, “Forage Crops for Hogs in Kansas and Oklahoma, 1908. 147, “Winter Forage Crops for the South," 1902. 502, “ Timothy Production on Irrigated Land in the Northwest," 1912. 509, “ Forage Crops for the Cotton Region,” 1915. 271, “ Forage Crop Practices in Western Oregon and Western Washington,” 1906 462, Logged-off Land for Pasture in West Oregon and Washington.” 1125, “ Forage for the Cotton Belt,” 1920. 420, Oats, Distribution and Uses,” 1910. * Winter Oats for the South,” 1911. 427, “ Barley Culture in the Southern States," 1910. 518, “ Barley Culture,” 1912. 968, “ Cultivation and L’tilization of Barley,” 1918. 724, “ The Feeding of Grain Sorghums to Livestock," 1916. 972, “ How to Use Sorghum Grain," 1918. 1137, “ Grain Sorghums: How to Grow Them,” 1920. 973, “Soy Bean: Its Culture and Uses," 1918.

3. What per cent of hulls do oats generally contain, and in what way are

the hulls of importance in feeding farm animals ? 4. What is "ground feed," and to which classes of animals is it generally

fed? 5. What are grain screenings? State under what conditions they may be

safely used, and what disadvantages are incident to their use. 6. Give the different kinds of sorghums used for feeding farm animals, and

the special points in their favor. 7. Name the leguminous seeds used for stock feeding, and give their average

composition and relative value in comparison with the cereal grains. 8. What oil-bearing seeds are used for stock feeding, and under what con

ditions are they used ? 9. Why is cotton-seed meal a better stock feed than cotton seed ? 10. To which classes of farm animals are (a) flax, (b) cotton-seed fed when

available for stock feeding ?

CHAPTER XVII

VARIOUS FACTORY BY-PRODUCTS

I. FLOUR AND CEREAL MILL FEEDS

In the manufacture of four or cereal products (breakfast foods) a large number of by-products are obtained that are of the highest value for stock feeding.

The flour-mill feeds are well-known by-products that have long been standard feeding stuffs in all parts of the country where livestock are kept. These are bran, middlings or shorts, and lowgrade feeding flour. A brief statement of the minute structure of the wheat kernel will make clear the characteristic differences in these by-products.

The wheat berry is covered by three different coatings of tough, thick-walled cells, which contain a considerable proportion of fiber and but little starch. Directly beneath the innermost seed-coat is a layer of cells, very rich in protein, called the aleurone layer; inside of this is the soft white portion (endosperm) of the berry, made up of cells largely filled with starch grains. These also contain protein substances, known under the name of gluten (gliadin and glutenin, see p. 9). Within the inner starchy portion of the berry is found the germ containing the embryo of the wheat plant. The following figures show the approximate proportion of the different parts of the wheat berry, according to Bessey:

Coatings or bran layers

5 per cent Aleurone layer .3 to 4 per cent Starch cells

.84 to 86 per cent Germ

6 per cent

.

Wheat is the main bread grain in this country. In the manufacture of flour the wheat is first passed over a series of screens which remove the impurities contained therein, such as weed seeds, chaff, etc. (p. 170). It is then scoured, and, after being heated somewhat, is run through a series of rollers, set at decreasing distances apart, so that the kernels are gradually broken into smaller and smaller pieces. The fine floury portion formed is separated after each “break,” and the tough outer seed-coats are thus gradually freed from adhering flour and make up the bran. The aim of the miller is to obtain all the starch cells and gluten possible from the wheat, and to avoid the germ and the bran, including the aleurone layer, which would give an undesirable yellow tinge to the flour and lower its keeping quality. There are considerable differences in the nomenclature of mill feeds adopted by millers in different sections of the country, but the more common terms recognized by the trade are wheat bran, shorts or standard middlings, white middlings, and red-dog flour.

Wheat bran is rich in protein and fat, and also in fiber, the average percentages of these components being about 15, 4, and 10 per cent, respectively. Its digestibility is lower than that of the cereals, viz., dry matter 66 per cent, protein 77 per cent, fiber 41 per cent, nitrogen-free extract 71 per cent, fat 63 per cent, making the percentage of digestible components:

Protein 11.9 per cent,
Carbohydrates and fat 47.6 per cent (X.R., 1: 4.0).

Bran is rich in mineral matter, and contains about 80 per cent of the phosphorus of the wheat berry; hence, it is very valuable as a source of this important element in feeding young, growing, or milk-producing animals. The ash is relatively poor in limet; in feeding wheat bran to these animals, it should, therefore, be supplemented by feeds that are especially rich in this component, like hay of legumes. Wheat bran also contains 6 to 8 per cent of the organic phosphorus compound phytin, to which constituent it largely owes its laxative properties.

The wheat bran on the market is of two kinds: Country-mill bran and roller or flaky bran. The former kind comes from small flour mills which do not have the perfect machinery for the separation of starch-cells from the seed coats that is found in large roller mills; this bran is, therefore, higher in starch and lower in protein and fiber than roller bran. The value of the two kinds for feeding purposes will depend largely on the combinations in which it is fed, and the kind of animals fed. While roller bran supplies more protein than does country-mill bran, its digestibility is likely to be somewhat lower on account of its larger fiber content. The differences in the nutritive values of the two kinds of bran are, in general, small, however, making it advisable, in case both kinds are available, to select whichever can be obtained at the lower price.

Wheat bran is often high-priced in comparison with other desirable concentrates, and farmers should study the market prices of different feeds and the feed bulletins issued by the various experiment stations so as to be able to take advantage of low market prices for other feeds that may serve their purpose equally well.