10 
BULLETIN 37, U. S. DEPAKTMENT OF AGKICULTURE. 
pound dried blood. These figures do not include bone or concen- 
trated tankage from tank water. 
From the figures estimated by the Bureau of Animal Industry as 
representing the total slaughter of cattle, calves, swine, and sheep 
in the United States, in 1912, it has been calculated that if all the 
materials rendered available by this slaughter had been saved and 
converted into tankage and dried blood they would have produced 
222,535 tons of tankage and 79,794 tons of dried blood. 
The present supply of tankage and dried blood depends largely 
on the output of the large packing houses, as the waste from the 
smaller ones is not so available for use as fertilizer. An increase in 
the output of these materials depends on the growth in size and 
number of the large abattoirs and the more complete utilization of 
the waste from the smaller slaughterhouses. The chances for any 
considerable development in the former manner are considered rather 
remote, owing to the settling of lands formerly devoted to the grazing 
of cattle. With regard to the latter manner of increase speculation 
perhaps is idle. All things considered, it may be said that the chances 
for any large immediate increase in the supply of tankage and dried 
blood appear rather poor. 
In this connection it should be pointed out that in Denmark country 
killing is being practiced on a cooperative basis in small community 
abattoirs, with the careful preservation of all the blood and much of 
the tankage. The introduction of this system among American agri- 
culturists undoubtedly would result in the increased output of both 
blood and tankage and should render available for fertilizer and feed- 
ing purposes the greater proportion of the 75 per cent of these prod- 
ucts created in country killing and now permitted to go to waste. 
Table XII. — Estimated slaughter of cattle, swine, and sheep during the fiscal year of 1912. 
[Estimate by Bureau of Animal Industry.] 
Slaughter. 
Cattle. 
Calves. 
Swine. 
Sheep and 
lambs. 
7, 500, 000 
5,000,000 
2,300,000 
3, 700, 000 
43,000,000 
23,000,000 
12,500,000 
2,500,000 
Total 
12, 500, 000 
6, 000, 000 
66,000,000 
15, 000, 000 
In deriving the estimate of yield of tankage and blood from the 
slaughter represented by the above figures it was assumed that all 
the tankage and blood were saved from the animals killed by whole- 
sale and 25 per cent of that from the retail and country killed. It is 
believed that the former estimate is too great and that not all of the 
tankage and blood obtainable from the wholesale slaughter is saved, 
though the greater proportion of this surely is saved. For the amount 
