122 Report oF THE DEPARTMENT OF ANIMAL HUSBANDRY OF THE 
for each pound gain than did the contrasted lot (Lots XII, XIV 
and XVI) having vegetable food supplemented by bone ash. On 
the average about 13 per ct. more food was required. 
Less than 7 per ct. more food was required by Lot XXII of 
laying hens for each pound of eggs produced than was required 
by Lot XXI. 
Lot D of ducklings required over 30 per ct. more food for each 
pound of gain in weight than did Lot C having animal food. 
GENERAL CONCLUSIONS. 
In some feeding experiments conclusive results can be obtained 
in a direct manner from a few animals. In other feeding experi- 
fents, however, where mixed foods must necessarily be used longer 
than for a short time, many conditions exist which cannot be 
subjected to particular control, and the nature of the evidence is 
so largely circumstantial that conclusions can only be satisfactory 
when they are based upon data from several feeding trials and a 
larger number of animals. In these experiments relating to the 
use of animal food, including the preliminary trials reported in 
Bulletin 149, 1,000 chicks and 170 ducklings were grown to mar- 
ketable size; 90 hens and 40 cockerels were used. The results, 
therefore, not any of which are of conflicting nature, seem to 
justify certain conclusions. 
In general, rations containing animal food appear more palat- 
able than rations of somewhat similar chemical composition con- 
sisting wholly of vegetable food. ations in which the lack of 
palatability was overcome by using an unusual variety of grain 
foods were inferior for growing chicks and laying hens and de- 
cidedly inferior for ducklings to rations in which nearly one-fifth 
of the dry matter was supplied by animal food. After the period 
of most rapid growth had passed and the young birds approached 
maturity the difference in the efficiency between such rations rap- 
idly disappeared. 
