774 EXPERIMENT STATION RECORD. 



weight. All cows were kept farrow. A maintenance trial was made for 7 cows 

 using the same ration as fed when in milk. A 10-day digestion trial was made 

 for 5 of these when at maximum milk production and again when on mainte- 

 nance. 



" The data bear out the results of others that more energy value is required 

 in the ration for rich milk than for milk lower in fat. The maintenance re- 

 quirements for the 7 cows showed some variation but was close to Armsby's 

 standard for cows of the same weight. 



" The protein fed was in excess of that called for in the standard of Armsby 

 or Haecker but no attempt was made to determine the minimum requirement. 

 When the energy value of the ration, in excess of maintenance, was calculated 

 by the use of 'production value' tables it was found that the cow producing 

 milk with 3.4 per cent fat used 0.245 therms per pound while one with milk 

 averaging 6.09 per cent fat used 0.524 therms per pound. 



" When Haeker's maintenance requirement was used and the amount of 

 ' digestible nutrients ' calculated by using Henry's tables it was found that 6 

 cows used more than Haecker's standard and 4 less. When actual maintenance 

 was deducted every cow used nutrients in excess of this standard. The de- 

 ficiency increased with the richness of the milk. Four Jersey cows required 

 from 23.1 per cent to 55.2 per cent more nutrients than called for by Haecker's 

 standard. This standard is clearly too low for cows with rich milk. According 

 to average digestion coefficients the 5 cows should have digested 70.8 per cent 

 of the ration received during the digestion trial when in milk. The results 

 showed only slight variation with individuals and an average of 65.57 per cent 

 digested. On maintenance the same cows should have digested 66.69 per cent 

 of the ration received, according to average figures, but the results were higher 

 in every case and showed an average of 71.2 per cent. 



"A calculation based upon the chemical analyses of the feed and the actual 

 digestion coefficients showed the actual energy value used in the feed per pound 

 of milk was lower than indicated by applying Armsby's * production value ' 

 tables directly to the ration received. The cow producing milk with 3.4 per cent 

 fat actually used only 0.235 therms per pound milk while for 6.09 per cent fat 

 the requirement was 0.442 therms. The total energy required in the feed was 

 slightly less per pound fat produced in the richer milk. However, after sub- 

 tracting maintenance the energy per pound fat is consistently higher for the 

 richer milk. 



" The cheaper production of fat in the richer milk is shown to be due to a 

 smaller maintenance requirement per unit of fat on account of the smaller 

 size of the animals producing the richer milk. The energy value of the milk 

 solids is greater In proportion to the energy value of the feed required with 

 the milk lower in fat. This indicates the production of rich milk requires an 

 increase in feed in excess of the increase in energy value of the milk. The 

 cow is able to utilize energy in her ration to better advantage than is indicated 

 by Armsby's 'production value' tables, which are based upon experiments 

 with mature fattening animals. A tentative standard is given of energy value 

 and protein for cows producing milk from 3 to 6.5 per cent fat." 



Feeding" sug-ar-beet pulp to dairy cattle, L. Malpeaux (Vie Agr. et Rurale, 

 3 {1912), No. 1, pp. 13-16). — In trials comparing the value of ensiled beet pulp 

 and beet fodder for dairy cattle it was observed that the pulp showed superior 

 qualities for milk production, evidently due to its sugar content which de- 

 velops during the ensilage process. Ensiled pulp of good quality evinced no 

 harmful influence on the quality of the milk, aside from a tendency to in- 

 creased acidity and a special flavor. 



