36 BULLETIN 1413, U. S. DEPARTMENT OF AGRICULTURE 
ments in 1903. suggested the employment of cocoa shells in the 
preparation of a substitute for skim milk for calves. Lucas (29) 
replaced 3.3 pounds of wheat bran, in the ration of dairy cows, 
with -±.4 pounds of cacao shells, with the result that the flow of 
milk was materially decreased. He concluded that the unfavor- 
able effect of the shells was due not only to their low nutritive 
value, but to the presence of a substance inimical to milk secretion. 
Data on the amounts of digestible nutrients in cacao shells were 
reported by Kellner many years ago. More recently, Lindsey and 
Smith, of the Massachusetts station, working with sheep, deter- 
mined the actual percentage of digestibility (coefficients of digesti- 
bility) of the nutrient constituents of commercial cocoa shells (28). 
They also fed shells to dairy animals and found that from 1 to 3 
pounds, mixed with grain, could be fed daily. 
The alkaloid content of the shells, in relation to their use as 
stock food, seems to have been ignored in these earlier investiga- 
tions cited, and scant consideration appears to have been given to 
the possible toxic action of the theobromine and caffeine until, 
during the World War, several French army horses were fatally 
poisoned, following the feeding of 1.5 kilograms (3.3 pounds) of 
shells per day. Marchadier and Goujon (33), who were the first 
to report the poisonings, made a study of the toxicity of the shells 
in connection with one of the cases, in which seven horses died. 
The shells under suspicion were found to contain (average) 0.68 
per cent of theobromine and 0.22 per cent of caffeine; so that each 
horse ingested 13.5 grams of the alkaloids per day, or a total of 
54 grams in the four days preceding death. The investigators con- 
cluded that the deaths were caused by the alkaloids in these cacao 
shells, and they suggest that the absence of ill effects following 
the feeding of shells to horses by earlier investigators may have 
been due to a lower alkaloid content of the shells used (Compare 
Zipperer (61)). Another case of poisoning of French army horses 
is reported by Fonzes-Diacon, who found 0.7 per cent of theo- 
bromine in a sample of the cacao shells that had been fed to the 
horses (15). 
Later, Rothea (40) reviewed both of the preceding investiga- 
tions, and reported the analysis of a sample of ground cacao shells 
which he found to contain 1.09 per cent of theobromine. This ma- 
terial contained 9.36 per cent of fat, and 2.77 per cent of nitrogen, 
and may therefore have contained an appreciable amount of cacao 
nib, and have been comparable to some of the " cocoa-shell meal " 
marketed in America. Rothea also suggests that the residues of 
shells made safe for feeding through extraction of the alkaloids 
would have but slight nutritive value. 
One of the latest reports on the suitability of cocoa by-products 
for feeding purposes is that by Griffiths (17). After summarizing 
much of the preceding work, he concludes that the use of cocoa 
shells and meal as a feed stuff " can not be considered." A number 
of proximate feed analyses of cocoa shells are to be found scattered 
through recent experiment station reports (9, p. 10: 35, p. 230; 
43, p. 69). For the most part these show that commercial shells 
generally contain appreciable quantities of nibs. 
