io The: Colorado Experiment Station. 
ration. With grain at one cent per pound and tankage at two cents 
per pound, the grain and tankage ration, with the grain forming 
five-sixths to nine-tenths of the ration, will cost from about $4.50 
to $5.25 for each 100 pounds gain upon fattening pigs under two 
hundred pounds live weight. 
What Selected Tankage Is .—The following description of the 
manufacture of Digester Tankage by Swift & Co., of Chicago, 
under date of Oct. 3, 1908, gives a good general idea of the 
methods used in the manufacture of selected tankage for feeding 
purposes. Such tankage does not contain any part of the animal 
carcasses condemned because of disease, and if any disease germs 
should find their way in with foreign matter they would be de¬ 
stroyed by the cooking process with live steam under pressure. 
“Digester Tankage is made from small scraps of meat trimmed 
from residues left in tanks after edible lard and tallow have been 
extracted from the carcass trimmings, and residues incident to the 
production of meats for human food purposes. These materials 
are taken onlv from animals which have been U. S. Government 
inspected and passed. This meat is a finished product and is a safe 
feed, absolutely free from diseased germs. 
“In the process of manufacture, the materials mentioned are 
placed in large tanks which are then sealed and the mass subjected 
to live steam, usually under a pressure of 40 pounds. The cooking 
process is timed for four to six hours, depending upon the char¬ 
acter of materials handled. When the cooking is completed the 
steam is turned off and tanks allowed to settle. When the liquid 
fat is found in a layer at the top it is removed. The residues con¬ 
sist of a watery solution, and at the bottom of the tanks a mixture 
of small pieces of meat and bone. The liquid is drained off to be 
dried separately and the solid meat—“The Tankage”—allowed to 
drain; it is then dried in large steam-heated rotary ovens in which a 
high temperature is maintained. The dried tankage is ground and 
put through a mill and screened to the desired fineness. It is then 
packed in ioo-pound sacks ready for shipment. 
“Digester Tankage has a very uniform composition, guar¬ 
anteed 60% Protein, 6% Phosphates, and 8% Fat.” 
Armour Packing Company, of Kansas City, make the follow¬ 
ing statements under date of October and November, 1908: 
“Our guarantee to the State of Kansas regarding meat meal 
is as follows: 
‘Made from regular run of good conditioned cattle 
and sheep offal from which oils and greases have been 
extracted. Sold under guarantee to contain a minimum 
of sixty per cent (60%) Protein, but will run as high as 
sixty-five per cent (65%) in certain lots.’ 
