122 Report of tiik Dki'aktmkxt of Animal IIusbandiiy of the 



for each pound gain than did the contrasted lot (Lots XIT, XIV 

 and XVI) having vegetable food supplemented by bone ash. On 

 the average about 13 per ct. more food was required. 



Less than Y 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 COJ^TCLUSIONS. 



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, manv 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 gi'own to mar- 

 ketable size; 90 hens and 40 cockerels were used. The results, 

 therefore, not any of wliicli 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. Rations in which the lack of 

 palatability was overcome by using an unusual variety of grain 

 foods were inferior for gi'owing 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. 



