Principles and Practice of Stock Feeding 15 



formulation of the food requirements of farm animals. Feeding experi- 

 ments, the careful observation of practice and the study of animal nutrition 

 have all contributed to this end ; and, as a result, several "'feeding stand- 

 ards " have been proposed. These standards have been classified under 

 three heads as the "physiological standard," the "formula for profit," 

 and the " average feeding ration." 1 They may be termed the physiolog- 

 ical, practicable, and the average standards. 



1. Physiological standards. — These are meant to express the propor- 

 tions of digestible nutrients best adapted to various animal needs and to 

 the sundry purposes for which stock is kept. A large part of the total nutri- 

 ents are required for mere maintenance, to keep the animal alive without 

 deterioration. The residue, if any, is applied to production. Much expe- 

 rimental work with stock, mainly bovine, has afforded some notion of the 

 relation between bodily needs and food supply. Yet differences among 

 individuals, breeds and species, as well as fodders and feeds, environments, 

 climates, care, etc., and among feeders, are wide ; and, moreover, analytical 

 methods are imperfect. Hence while physiological needs are known, ab- 

 solute standards based on definite requirements cannot be fixed. They are 

 both irrational and impossible. The use of these standards, then, is hedged 

 about with many limitations which should be clearly apprehended lest 

 these formulas which are extremely helpful if properly used become mis- 

 leading. 



The physiological standards are clearly expressed, easily understood 

 and readily used. On their face, if considered apart from the qualifications, 

 they make stock feeding essentially a branch of applied mathematics. 

 Their very simplicity and directness, however, are their fault, their 

 strength is their weakness, for animal life and nutrition are too complex to 

 be computed by mathematical rule. 



The study of the requirements of the individual animal and the adapt- 

 ing of food to its needs is to be preferred to placing the herd, as a whole, 

 upon any inflexible ration. The capacity of an animal to receive, its ability 

 to produce, the effects of the sundry feeds upon the health and condition of 

 the animal, upon its appetite and taste, upon the quality of the product, 

 the money values of feed and the profits to be derived from their use, are 

 important considerations which do not enter into the makeup of the physio- 

 logical standard but which are vital factors in the feeder's problem. 

 Clearly the physiological standards may supplement and in some measure 

 guide judgment, but cannot take its place. 



Under the head of physiological standards, may be listed the original 

 Wolff or " German " standards, the Kuehn standards, the Wolff standards 

 as modified by Lehmann, and those proposed by Atwater and Phelps (Con- 



i Atwater. Conn., (Storrs) Sta. Rpts. 7, pp. 268-221 (1894), 10, pp. 112-119(1897). 



