12 FEEDS AND FEEDING 



having lower feeding value; and nitrogen-free extract, which is easily 

 digested and hence has much higher value. 



22. Concentrates and roughages. These terms are used to differ- 

 entiate feeds of a coarse, bulky nature from those which are more con- 

 densed and nutritious. 



Concentrates are feeding stuffs of condensed nature, which are low in 

 fiber and hence furnish a large amount of digestible matter. Examples 

 of this class of feeds are the various grains, such as Indian corn, wheat, 

 and oats, and milling by-products of high feeding value, such as wheat 

 bran, linseed meal, gluten feed, etc. 



Roughages are the coarser feeding stuffs, which are higher in fiber and 

 supply a lower percentage of digestible matter. Such feeds as hay, 

 corn fodder, straw, and silage belong to this class. Some of the low-grade 

 milling by-products, such as oat hulls, ground corn cobs, and peanut 

 hulls are roughages, rather than concentrates, for they are largely fiber 

 and furnish but little nutriment. Roots are watery and bulky, and 

 contain relatively little nutriment per pound, yet based on the composi- 

 tion of their dry matter they are more like concentrates than roughages, 

 as they are low in fiber. They are really watery, or diluted, concentrates, 

 tho for convenience they are included under fresh green roughages in 

 Appendix Table I. t 



III. THE STUDY OP AN ACRE OF CORN 



The great basic facts in plant life, briefly set forth in the preceding 

 pages, are admirably illustrated by a study of Indian corn, the greatest 

 of our agricultural plants, such as has been made by Ladd at the New 

 York (Geneva) Station 1 and Jones at the Indiana Station 2 . 



23. Changes in a growing corn crop. Analyzing the plants at various 

 stages from July 24, when they were about 4 feet high, until Oct. 8, when 

 the kernels were hard, Jones secured the data which are given in the 

 table on the next page. These figures are based on an average stand of 

 10,000 stalks per acre. 



From July 24, at a stage when sometimes fed as soilage, to Aug. 28, 

 when the silks were drying, the crop increased over 19,000 Ibs. in total 

 weight and nearly 4,000 Ibs. in dry matter. The increase was thereafter 

 less rapid, the total weight reaching the maximum when the kernels were 

 in the milk stage. After this it decreased by over 4,000 Ibs., due to the 

 drying out of the crop as it matured. The dry matter, however, con- 

 tinued to increase rapidly until the plants were fully ripe. Indeed in 

 less than a month following Aug. 28 the acre of corn stored over 3,000 

 Ibs. of dry matter! 



1 N. Y. (Geneva) Rpt. 1889. 

 2 Ind. Bui. 175. 



