Feeding Tables and Standards. 109 



ous feeding stuffs, and so there were about as many tables of " hay 

 equivalents ' ' as there were writers on economic agriculture. Im- 

 perfect as it was, Thaer's table served to draw attention to an 

 important subject and was the beginning of something far more 

 elaborate and useful. 



139. The first feeding standard. In 1859 Grouven 1 proposed 

 the first feeding standard for farm animals, based on the total 

 quantity of protein, carbohydrates and ether extract found by 

 analysis in feeding stuffs. This standard fell short of require- 

 ments, since it considered the total nutrients instead of the digesti- 

 ble portion. 



140. Wolffs standards. In 1864, Dr. Emil v. Wolff, the great 

 German scientist and author, published for the first time, in 

 Mentzel & v. Lengerke's Agricultural Calendar, standards based 

 upon the digestible nutrients of feeding stuffs. In these stand- 

 ards the attempt was made to meet the physiological require- 

 ments of the animal by supplying sufficient protein, carbohydrates 

 and ether extract for all the needs of the body, without waste of 

 any of the nutrients. Wolff's feeding standards have become 

 popular among the more progressive American farmers and 

 stockmen and have been used wherever agricultural science 

 is recognized. Their popularity is due in a large measure to 

 their simplicity, ease of application, and the positive character 

 of the statements made. In these standards, accompanied by 

 tables of digestibility, the stockman has before him the data 

 necessary to calculate rations for the different farm animals, little 

 or nothing being left in uncertainty. 



141. Kuehn's position. The strength of Wolff's standards is 

 also their weakness, for such mathematical statements cannot 

 stand without marked qualifications when dealing with the com- 

 plex problem of animal life and its nurture by food. 



Julius Kiihn, another German writer and investigator of the 

 highest repute, holds 2 that Wolff's standards "are objectionable 

 and misleading to the farmer. 77 According to this author, Wolff 



1 Feeding Standards for Domestic Animals, Expt. Sta. Rec., vol. IV; 

 also Agricultur-Chemie, Koln, 1859, p. 603. 



2 Feeding Standards for Domestic Animals, Expt. Sta. Rec., vol. IV, 

 pp. 6-13. 



