COMPOSITION OF FEEDING-STUFFS 5 



The tables in the Appendix of this volume show 

 clearly how considerably the amount of water in 

 the various feeding-stuffs varies. Those which con- 

 tain the most water are fresh slices of beetroot, 

 with 93% water ; then the roots and tubers, with 

 68-90%; followed by the green fodders, with 

 70-90%. Hay and straw contain about 12-17%, 

 cereal grains 11-15%, whilst oil cakes and oil cake 

 meals have only 9-13%. As a rule oily seeds (7-9%) 

 and dried by-products, such as brewers' grains 

 (7-12%), contain the least amount of moisture. 



A knowledge of the quantity of water in a food- 

 stuff is of great importance, not only as an indica- 

 tion of its feeding value, but also in respect to its 

 keeping properties. Most meals and cakes easily 

 undergo decomposition if they contain more than 

 14% of water. 



(2) The Proteins. 



The proteins are a group of substances which vary 

 a good deal in their properties, but agree in contain- 

 ing nitrogen. White of egg (albumin), the casein 

 of milk, lean meat, wheat gluten, are amongst the 

 best-known of these substances. In spite of the 

 variations which they show in chemical compo- 

 sition there is sufficient agreement to enable them 

 to be placed in one class. The proteins contain 

 from 50-6-55-2% of carbon, 15-0-18-4% of 

 nitrogen, 6-5-7-3% of hydrogen, 20-8-23-6% of 



