46 



MAINTENANCE EAT IONS OF FAKM ANIMALS. 



energy of tlie rations consumed from the data given in Bulletin 71 of the Penn- 

 sylvania station with the following results: 



Maintenance rations of yearling steers — Evvard. (First experiment.) 



No. of 

 animal. 



Length 

 of experi- 

 ment. 



Average 



live 

 weight. 



Estimated available 

 energy per day. 



Per head. 



Per 1,000 

 pounds 1 



live 

 weight. 



590 

 598 

 596 

 595 



Days. 

 60 

 60 

 60 

 362 



Pounds. 

 608 

 461 

 464 

 609 



Therms. 

 5.63 

 3.85 

 4. 34 

 5.83 



Therms. 

 7. 85 

 6.45 

 T. 25 

 8.09 



1 Computed in proportion to the two-thirds power of the live weight. 



In addition to the uncertainty attaching to such live-weight experiments, as 

 well as to the fact that the available energy was estimated, there is also a special 

 difficulty in determining the true maintenance requirement of growing animals, 

 which will be referred to later. Nevertheless, the results appear to agree fairly 

 well with those obtained in the respiration calorimeter experiments. 



The metabolizable energy of the rations, also computed from the data given 

 in Bulletin 71 of the Pennsylvania station, is, on the other hand, lower than 

 fhat found in either the Pennsylvania or the Moeckern experiments, although 

 agreeing well with Haecker's results on dry cows, viz, per 1,000 pounds live 

 weight : 



Therms. 



No. 590 10.42 



No. 598 8.57 



No. 596 . 9. 63 



Average 9. 54 



Evvard's first three animals were also fed a maintenance ration of the same 

 feeds in the same proportions for 120 days after having been previously fed 

 heavier rations for 127 days, during which No. 590 received about one-fourth of 

 full feed, No. 598 about one-half, and No. 596 full feed. The results of this 

 second maintenance period are summarized in the following table : 



Maintenance rations of yearling steers — Evvard. {Second experiment.) 



No. of 

 animal. 



Length 

 of experi- 

 ment. 



Average 



live 

 weight. 



Estimated available 

 energy per day. 



Per head. 



Per 1,000 

 pounds 



live 

 weight. 1 



590 

 598 

 596 



Days. 

 120 

 120 

 120 



Pounds. 

 706 

 665 

 860 



Therms. 

 6. 47 

 6.44 

 9.66 



Therms. 

 8. 15 

 8. 45 

 10. 62 



i Computed in proportion to the two-thirds power of the live weight. 



