342 SCIENTIFIC FEEDING OF ANIMALS 



If in drawing up feeding standards for milch 

 cattle the " value " or " quanti valence " (p. 90) of 

 the food-stuffs is taken into account, the following 

 considerations must be noted. First of all it is 

 clear that the energy required for the work of 

 mastication and digestion, and also losses due to 

 fermentation and putrefaction, must be the same 

 in male and female animals of the same species. 

 Many observations made by those whose work is 

 the control of milk supplies, and also experiments 

 carried out on food-stuffs of different " values," 

 have shown that calculations based on the starch 

 equivalents are also correct for milking stock. In 

 an experiment with 24 cows, for example, there 

 was the same amount of digestible nutrients always 

 given, but in the first and last periods of the experi- 

 ment one part of the nutrients was replaced by 

 mangels, in the second period by dried beet slices, 

 and in the third by beet slices made into silage. 

 The starch equivalent of the mangels was 2-00 kg., 

 of the dried beet slices 2-35 kg., and of the silage 

 2-65 kg., and it was found that the milk yields 

 stood in the same relation, namely, the dry slices 

 gave per day per head 0-95 kg. more milk than the 

 mangels, and the silage slices 172 kg. more, the 

 fat contents of the milk remaining unchanged. 



In another experiment, a leguminous straw which 

 was rich in crude fibre was compared with clover 

 hay, and there was also here an increase of -51 kg. 



