ENERGY VALUE OF FEEDING STUFFS 169 



one year it should be one-fortieth for ruminants, while more mature, 

 producting herbivora may have as high as one-thirty-third of their live 

 weight. Mature horses, work oxen and boars require one-fortieth, and 

 growing pigs, after weaning, and fattening swine demand one-thirty- 

 third of their live weight in the form of dry matter. While the values 

 given should be rather closely followed for the digestible nutrients, a 

 variation in the total dry matter, amounting to 10 per cent, is of less con- 

 sequence, provided always that any change from the accustomed volume 

 is made gradually. A considerable proportion of the dry matter for 

 herbivora is furnished in the form of hay, horses requiring about (5) 

 8-10 (20) pounds, cattle (6) 12 (28), sheep (1) 2 (4-5) pounds per 

 day per head, or, figured on the basis of live weight, horses one one- 

 hundredeth, cattle one-eightieth, and sheep one-fiftieth per total live 

 weight. 



In the past, feeding rations were based on the chemical composition of the feeding 

 stuffs, under the impression that a correct relative proportion of the nutrient ele- 

 ments was all that was required. But Kellner has pointed out the fallacy of this 

 assumption. "Should we persist in this assumption and ascribe equal values to the 

 various nutrients, irrespective of their source, whether contained in straw or in the 

 grains, we should blunder most seriously. Nor should the crude fiber of the various 

 feeding stuffs be looked upon as useless and our attention confined to the other 

 ingredients as formerly. This would be a serious mistake." 



The value of crude fiber is subject to variation. The crude fiber contained in 

 certain feeding stuffs requires more energy for its digestion than it furnishes the 

 organism. In other feeding stuffs a certain amount of the digested crude fiber is 

 equal in value to that of starch. The fact that the energy value of a feeding stuff 

 does not correspond directly to its chemical composition is due to its variable physical 

 character (its requirement for mastication and overburden of the digestive tract), 

 to its characteristic chemical "structure," its possible content of valuable nonnutri- 

 ents (enzymes and stimulants) as well as to its mere bulk or volume, its behavior 

 toward fermentative processes, etc. 



Kellner has determined the energy value of the most important feed- 

 ing stuffs and introduced it in the calculation of rations. The energy 

 value of a feeding stuff includes the total productive action of all of the 

 digestible organic substances, hence all of the albumen or protein, fat and 

 carbohydrates combined. The energy value of starch is used as a basis. 

 In the calculation of feeding rations, according to Kellner's method, it is 

 necessary to consider only the starch value and the digestible proteids. 

 This not only simplifies calculations but, since the peculiarities of the 

 different feeding stuffs are also taken into consideration, the results are 

 considerably more accurate. 



The starch value of feeding stuffs the nutrients of which are 100 percent avail- 

 able can be readily calculated. According to Kellner, thus : 



1 part of digestible protein = 0.94 parts of starch value. 



1 part of digestible fat, in roughages, chaff, root crops and their by-products = 

 1.91 parts of starch value. 



1 part of digestible fat in grains and their by-products not belonging to the oil- 

 producing seeds = 2.12 parts of the starch value. 



1 part of fat in oil cake or meal = 2.41 parts of starch value. 



1 part of digestible nitrogen-free extract and crude fiber (combined) = 1.0 parts 

 of starch value. 



Since the digestible nutrients of only a few feeding stuffs (potatoes, corn, hulled 

 rice, some feed meals, oil seeds and oil cake, gluten, and feeding stuffs of animal 



