UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1166 
Washington, D. C. T July 26, 1923 
APPLE BY-PRODUCTS AS STOCK FOODS. 
By G. P. Walton. Assistant Chemist, and G. L. Bidwell, Chemist in Charge, 
Cattle Food Laboratory, Miscellaneous Division, Bureau of Chemistry. 1 
PURPOSE OF INVESTIGATION. 
Shortly after the close of the World War American manufacturers 
became greatly interested in the possibilities of utilizing dried apple 
pomace and similar dried residues as stock foods. Information, 
founded on scientific research, concerning the feeding value of dried 
apple by-products and their effect on the production of milk when 
fed to cows was limited. Accordingly, the Bureau of Chemistry of 
the United States Department of Agriculture undertook an investi- 
gation of the utilization as stock food of dried apple pomace and 
dried apple-pectin pulp. Special attention was given to the value of 
the dried pomace and pectin pulp as sources of succulence for cows 
during the winter. 
UTILIZATION OF APPLE BY-PRODUCTS. 
The first industrial problem in connection with the by-products 
of the apple probably arose with the first crude attempts to prepare 
a drink from its juice. Evidently the early cider makers (1-fi)* 
were not greatly impressed with the value of cider press cake, or 
apple pomace, as food for stock, in spite of the fact that Cato and 
Varro (77) and other Roman writers on agricultural subjects had 
advocated the feeding of grape marc, the refuse from wine making. 
The use of apple pomace as a food for stock may have been ignored 
for the reason that, according to Evelyn (7) and Mortimer (4). the 
fruit employed for making cider at that time was so harsh that 
swine refused to eat it even before the juice had been extracted. 
In 1708 Philips {120), the first to mention in the literature the 
possibility of feeding apple residues to animals, recommended the 
final press cake from cider making as a fertilizer. By the end of 
1 The feeding trials with dried apple pomace and dried apple-pectin pulp reported in 
this bulletin were conducted at the Beltsville Experiment Farm, Bureau of Animal Indus- 
try. Dairy Division, T. E. Woodward. Dairy Husbandman, in d 
*The italic numbers in parentheses throughout this bulletin refer to tho literature 
cited, pages 35 to 39. 
44664°— 23 1 1 
