Feeding Standards — Calculating Rations. 105 



of feeding standards based on the digestible nutrients contained in 

 feeding stuffs. These standards set forth the amount of digestible 

 crude protein, carbohydrates, and fat required daily by the differ- 

 ent classes of farm animals. 



The value and importance of the Wolff standards were at once 

 recognized; and with their promulgation and adoption came the 

 first widespread effort toward the rational feeding of farm animals. 

 The Wolff standards were first brought to the attention of the 

 American people in 1874 by Atwater,^ America's worthy pioneer 

 in the science of animal nutrition. Armsby's Manual of Cattle 

 Feeding, based on Wolff's book- on the same subject, appeared in 

 1880. 



The Wolff standards are still popular among progressive Ameri- 

 can farmers and stockmen and have been used wherever agricul- 

 tural science is recognized. Their abiding popularity is due to their 

 simplicity, ease of application, and the positive nature of the state- 

 ments made. In these standards, accompanied by tables of the 

 composition and digestibility of feeding stuffs, the stockman has 

 all the data necessary to formulate rations for the different farm 

 animals, little or nothing being left to uncertainty. 



The AYolff feeding standards appeared annually in the Mentzel- 

 Lengerke Calendar down to 1896. From 1897 to 1906 they were 

 presented by Dr. C. Lehmann of the Berlin Agricultural High 

 School with but slight modification. In 1907, however. Dr. 0. Kell- 

 ner, the talented director of the Mockern (Germany) Experiment 

 Station, took charge of this portion of the Calendar and substituted 

 tables and feeding standards based on starch values, as elsewhere 

 briefly presented in this work. 



In this chapter are set forth the other feeding standards which 

 have followed those of Wolff, all seeking the same end in some- 

 what different ways. In their efforts to avoid the weaknesses of 

 the Wolff system, each gains in some particulars and loses in others. 

 In this work the Wolff standards are given first place because of 

 their historical and foundational importance. The student of feed- 

 ing problems should begin l)y familiarizing himself with them, no 

 matter where he closes his studies. 



II. Tables of Feeding Stuffs and the Wolff-Lehmann Standard 



Eations. 

 127. Nutrients.— The term nutrient is applied to any food con- 

 stituent, or group of food constituents of the same general chemical 



' Ept. Me. State Bd. Agr., 1874; Ept. Conn. Bd. Agr., 1874-5. 

 ' Tutterungslehre, 1st ed., 1874. 



