26 BULLETIN 459, U. S. DEPARTMENT OF AGRICULTURE. 
The first step is to compute, in precisely the same way as in the 
previous example, the estimated requirements of these cows per day 
as follows: 
Digestible | Net-energy 
protein. value. 
Pounds. Therms. 
HOT MAIN FeMan COs es Se = Sore wa Ae Sino oe ae at SS ee ee eee 0. 50 : 
For 24 pounds of milk: 
iProtein'24<0052 ass Seek ce caja sede. Hee Oe eee 125 iS eee 
Net energy 24X0.29...-..- Poke oh oS heeinitic ls eater Oe eee oe Oe SES oe Eee See | pe ere 6. 96. 
Notalirequirement.: 2... Slee oo. ons PAS Ae eee tee ee aoe oeeiee aie 1.75 12. 96 
The amount of silage and clover hay available: will furnish, ac- 
cording to the table on pages 11-13, the following amounts of dry 
matter, digestible protein, and net energy value: 
Total dry | Digestible | Net energy 
Kind and amount of feed. matter. protein. value. 
Cont silage. 32 pounds: soto eet: Sah ree oe noe eee ; 8. 42 0.19 5.09 
Clovyermhay, 8 poundss Oo rs ksh eee ee ses see 2 Sr ene Pesce exe 6.97 -39 3.09 
ol Woy Dats Sete pealcegn epee ai pre se SR eter me Nene re ae cy gees 15.39 58 8.18 
The question now is what feeding stuffs is it most economical to 
buy (or to refrain from selling if in stock) to complete the ration. 
The first step in deciding this question is to compare the various feeds 
as sources of energy and see which one furnishes a unit of net energy 
value at the lowest price. This computation gives the following 
results: 
4 ce Eneey ces of 
P ost of 1 value 1 therm 
Kind of feed. pounds. | of100 - | net energy 
| pounds. value. 
| Therms. . Cents 
(OY iSite ee ON a ios Sa ace Oe eM LN Ao eS aes oe ee $1.25 67.56 1.85 
WOTTINIMNOALS ets eee sr SON Soc A Sas re ee ete 1.25 88.75 1.41 
Vid 0132 1 0) a 0 pee ee en MR re oP Yeh ae bk 1.05 53. 00 1.98 
Wiheatemiid dings h is. esse oss es nl eae ieee ee 1.20 75.02 1. 60 
Dried bnuewer’s STAINS 2) 2 se o0 oe 5 ee Se eee ee TS 53.38 2.15 
MGlinbenem eal ee ae 0 1235 84.15 1.60 
Coptousbedsmeal ns oe Sas ee ene 1.50 90. 00 1. 67 
@Old-processiinseedimealee 32; 025. Sis ae eee 1.65 88.91 1. 86 
Evidently, if it were simply a question of supplying energy to the 
animals, we should use corn meal, since that supplies a unit of energy 
at a much lower price than any of the other feeding stuffs. If it 
were thought desirable to add variety to the ration, wheat middlings 
would obviously be our next choice. 
