Bee. 3, 1917 
Fatness of Cattle and Feed Utilization 
463 
Tabled XVIII .—Computed net energy values of concentrates per kilogram of dry matter 
Period No. 
Period 1. 
Period 2. 
Period 3. 
Period 4. 
Average for light rations. 
Average for heavy rations. 
Average in unfattened condition 
Average in fattened condition.. 
Gross 
energy 
(Table IX). 
Bosses in 
excreta 
(Table IX). 
Heat in¬ 
crement 
(Table 
XVII). 
Net 
energy 
value. 
Calories. 
Calories. 
Calories. 
Calories. 
4,562 
1,401 
| 1,288 
/ 1,873 
4,537 
*,33 4 
1 1,915 
/ 1,878 
1 1,783 
4,554 
4 , 548 
1,300 
*>389 
} 1*376 
4,555 
*, 395 
1*332 
I, 828 
1,897 
4,546 
1*317 
1*332 
4 , 55 ° 
1,368 
I, 288 
1,894 
4,551 
i >345 
1*376 
1,830 
SUMMARY 
(1) A steer in medium condition received, in two successive periods, 
an approximate maintenance ration and a fattening ration of the same 
standard mixture of hay and concentrates. The animal was then fat¬ 
tened and the comparison of a maintenance ration and a fattening ration 
of the same standard feed mixture was repeated. 
(2) The digestibility of the lighter ration was in both cases greater 
than that of the heavier one, although the difference was less than has 
usually been found in such comparisons. 
(3) The corresponding rations were digested equally well by the fat¬ 
tened and unfattened animal. 
(4) The relative losses of nitrogen, carbon, and energy in the urine 
were less on the heavy than on the light rations and a little greater in the 
fattened than in the unfattened state. 
(5) The production of combustible gases (methane), both as compared 
with the total feed and with the digestible carbohydrates, was notably 
less on the heavier than on the lighter rations. There was no distinct 
difference in this respect between the fattened and the unfattened states. 
(6) In consequence of the smaller losses in the urine, and especially in 
the combustible gases, the percentage of the gross energy of the feed 
which was metabolizable was greater in the heavier than in the lighter 
rations. No difference in this respect was observed between the fattened 
and the unfattened animal. 
(7) By far the larger share of the additional heat produced on the 
heavier rations was eliminated by means of evaporation of water. 
(8) The heat increment resulting from the consumption of a unit of 
feed was but little greater in the fattened than in the unfattened con¬ 
dition. Consequently the net energy values of the feed and the per¬ 
centages of the metabolizable energy which were available for gain were 
but slightly less in the fattened than in the unfattened condition. 
