ENERGY VALUES OF RATIONS FOR FARM ANIMALS. 



Maintenance requirements of sheep, per day and head. 



15 



Live 



Digestible 



Net 



Weight. 



protein . 



value. 



Pounds. 



Pounds. 



Therms. 



20 



0.013 



0.30 



40 



.028 



.54 



60 



.039 



.71 



80 



.050 



.87 



100 



.055 



1.00 



120 



.061 



1.13 



140 



.072 



1.25 



REQUIREMENTS FOR GROWTH. 



While young animals gain in weight faster than do older ones, a 

 j>ound of increase in live weight in the young animal contains much 

 more water and less dry matter than in the case of a more mature 

 animal. Moreover, the dry matter in the case of the young animal 

 contains relatively more protein and less fat, as a rule, than in the 

 older one, and fat contains much more chemical energy than protein, 

 the proportion being 1 to 1.67. The consequence is that a gain of 1 

 pound in live weight represents the storing up of much less energy 

 in the young than in the mature animal, and therefore requires a 

 smaller supply of energy in the feed. 



Unfortunately no very extensive determinations of the composi- 

 tion and energy values of the increase of live weight in growing 

 animals have yet been reported. The following estimates by the 

 writer, derived from such data as are available, may serve to give a 

 general idea of the requirements per pound of growth of cattle and 

 sheep at different ages, but they can not lay claim to any high 

 degree of accuracy. The figures refer to normal growth, with no 

 considerable fattening. 



Estimated energy value of 1 pound of gain in weight by growing cattle and sheep. 





Net 



Age. 



energy 





value. 



Months. 



Therms. 



3 



1.50 



6 



1.75 



12 



2.00 



18 



2.50 



24 



2.75 



30 



3.00 



The growing animal also requires a sufficient supply of digestible 

 protein for maintenance and to supply material for new growth. 

 No very systematic study of the latter requirement has yet been made, 

 but from the results of a considerable number of practical feeding 

 trials it is possible to make a fairly satisfactory estimate of the total 



