FEEDING DAIRY CATTLE 



97 



77 per cent of the corn meal was digestible. On account of 

 the energy required for digestion, still less was available for 

 use in storing up fat, or for producing milk. On the basis 

 of digestibility 168 pounds of timothy was equal to 100 

 pounds of corn, but for production purposes, that is, for 

 sto -ing fat, producing milk, or making growth, 269 pounds 

 of 1 imothy was necessary to equal 100 pounds of corn. Table 

 14 gives a comparison of the amounts of energy available 

 fro in corn and from timothy hay. 



TA SLE 14. ENERGY VALUES PER 100 POUNDS OF CORN MEAL 

 AND TIMOTHY HAY, EACH CONTAINING FIFTEEN PER CENT 



WATER 



It is not safe to compare roughage with grain on the basis 

 of digestible nutrients, but such a comparison between dif- 

 ferent classes of hay is fairly reliable, and grains may be 

 compared with grains on the basis of digestible nutrients. 

 The best way thus far found for comparing different feeds is 

 on the basis of the energy values for ' production. The 

 feeding standards given on pages 298 to 304 are based on 

 digestible material. Armsby's standards given in this 

 chapter are based on production values. 



91. Feeding Standards. The many analyses that have 

 been made enable us to know how much of each of the sev- 

 eral constituents is contained in all common feeds on the 

 average. It is also known that the cow needs all of these 



