24 BULLETIN 1166, r. S. DEPARTMENT OF AGRICULTURE. 
workers are the only ones which have been determined by actual di- 
gestion experiments. 
Few tests showing the effect on milk production of feeding fresh 
apple pomace to cows have been reported. Most investigators have 
merely generalized on its comparative merits. 
Johnson (93) stated that horses and colts ate frozen pomace "with 
evident relish and benefit, but that cattle would have none of it. 
Goessmann (71) quotes Wolff as stating that the " fodder constitu- 
ents " in pomace are worth more than those in the same weight of tur- 
nips and as much as those in sugar beets. 
Jenkins (91) fed pomace to horses and to cattle with good results. 
He states that it is prized as a food for these animals. 
Houzeau (87) assigned a much lower feeding value to pomace, in 
comparing it with hay, than that reported later by Lindsey. In his 
estimation, 10 pounds of straight (one-pressing) pomace, or 7 pounds 
of exhausted " small cider " residue (after three pressings) , 31 is equiv- 
alent to 1 pound of good hay. There is nothing in Houzeau's report, 
however, to indicate that his results were based on actual feeding 
trials. In fact, it is evident that he formed his opinion as to nutri- 
tive value on the content of crude protein. Furthermore, he dealt 
with pomace from French cider apples, which for generations have 
been grown with the view of obtaining a large yield of juice with a 
high content of tannins and sugars. Such pomace undoubtedly 
would contain less digestible matter than that from American sources, 
where, as a rule, good eating apples are used. 
Houzeau. and earlier LeChartier (97). directed attention to the 
effect of the thoroughness of extraction of the juice upon the quality 
of the resulting pomace. Exhausting the marc by repressing, 
especially with the addition of water, lowers the content of soluble 
carbohydrates but increases the proportion of crude fat and protein. 
European writers have assigned varying feed values to apple 
pomace. Desplanques (90) gives its nutritive value as half that of 
beets. He states that when feci to the extent of half the ration to 
cows it increases the milk flow. TVarcollier and Hediard (140) 
believe that it compares favorably with beet forage or with fresh 
beet pulp. Lhoste (97) states that approximately 3^ pounds are 
equivalent to 1 pound of good hay, a comparison evidently based on 
Kellner's data. 
In 1911 the Harleshausen Agricultural Experiment Station, Ger- 
many, compared apple pomace with maize (corn) meal as the basal 
ration for swine. The pomace proved to be the more economical 
when the supplementary feeds were potatoes, barley, wheat bran, and 
meat meal (80). 
Most of the earlier writers, especially the French, discuss the 
popular beliefs prejudicial to apple pomace, either fresh or ensiled. 
Before the cause of contagious abortion in cattle was discovered it 
was generally believed that the feeding of apple pomace was a con- 
tributing factor. With more reason, perhaps, pomace was often 
blamed for off-flavor in milk or butter. Investigators now agree, 
however, that this is due to a fermented 32 or decomposed condition 
a Tn France the press cake was broken up and reground with water between pressings. 
• : - Normal silage fermentation is not injurious, but aerobic acidification appears to be so. 
