120 FEEDS AND FEEDING 



This ration meets the standard with sufficient closeness. It falls 

 below by more than 1 Ib. of dry matter, due to the fact that the Wolff- 

 Lehmann standards were devised to cover the common systems of feeding 

 in Europe, where considerable straw or other low grade roughage is com- 

 monly included in rations for horses and ruminants. When only such 

 high grade roughages as silage and legume hay are used, rations which 

 supply enough digestible nutrients will fall below the standard require- 

 ment in dry matter. Provided the ration furnishes bulk sufficient to 

 distend the digestive tract properly, as in this ration, no further attention 

 need be paid to such a deficit. American rations will usually furnish 

 an excess of fat over the standard, as is the case with this ration. Then 

 the carbohydrates may fall somewhat below the standard as an offset, 

 it being borne in mind that 1 Ib. of fat will replace 2.25 Ibs. of carbo- 

 hydrates. (70) 



Several devices 5 have been suggested to shorten the work of computing 

 rations, but it seems best in this book to show how to perform the cal- 

 culations in the simplest and most direct manner. Thru such drill the 

 student will become familiar with the quantity and proportion of the 

 several nutrients in common feeding stuffs and the amount of these 

 required by farm animals according to the standards. 



IV. KELLNER 's STARCH VALUES AND FEEDING STANDARDS 



As has already been pointed out (78-80), the careful and laborious 

 investigations of Kellner, Zuntz, and Armsby have shown that the total 

 quantity of digestible nutrients in a feeding stuff is not necessarily the 

 true measure of its feeding value, as is assumed in the Wolff -Lehmann 

 feeding standards. These investigators have found that, to determine 

 the true net value of any given feeding stuff to the animal, it is necessary 

 to deduct the energy expended in the work of mastication, digestion, 

 and assimilation from the total available energy furnished by the digest- 

 ible nutrients in the feeding stuff. 



169. Kellner's starch values. As a result of his investigations Kellner 

 formulated feeding standards based on what he called * ' starch values. ' ' 6 

 He found that on the average 1 Ib. of digestible starch fed to the ox in 

 excess of maintenance requirements produced . 248 Ib. of body fat, and 

 other digestible pure carbohydrates had about the same value. Taking 

 1 Ib. of digestible starch as his unit, he found that 1 Ib. of digestible 

 pure protein had a starch value of 0.94 Ib. ; i. e., it would produce 94 

 per ct. as much body fat as 1 Ib. of digestible starch. Further, in oil- 

 bearing seeds and oil meal, in which the ether extract, or so-called ' ' fat, ' ' 

 is practically all pure fat, 1 Ib. of digestible fat had a starch value of 

 2.41 Ibs., while in roughage, roots, etc., it had a starch value of only 



"Willard, Kan. Bui. 115; Spillman, Wash. Bui. 48; Bundles, U. S. Dept. Agr. 

 Bui. 637. 

 "Ernahr. Land. Nutztiere, 1907. 



