1907.] PUBLIC DOCUMENT — No. 33. 63 



.96 cents both for the winter and summer periods. The 

 gross cost of food per egg on the corn ration for the winter 

 period was .86 cents and for the summer period .74 cents. 

 This year, as last, therefore, the food cost per egg has been 

 less on the corn than on the wheat. It is not easy to under- 

 stand why the results as measured by the number of eggs 

 produced in one instance should have been favorable to the 

 wheat and in the other to the corn, but it may be that the 

 difference in the average temperature of the two seasons in 

 part accounts for it. It will be remembered that both ra- 

 tions in this experiment are low in fat. One of the prod- 

 ucts of jDrotein metabolism in the animal body is fat, and fat, 

 as is well understood, is the most effective heat producer. 

 The higher protein content of the ration containing the more 

 w^heat may have proved serviceable, therefore, in enabling 

 the fowls the better to maintain normal body temperatures 

 during the cool weather. True, it is generally asserted that 

 corn may be used more freely as a food for laying fowls in 

 winter than in summer. It will be remembered, however, 

 that in this experiment the fat content of the wheat ration 

 was made equal to that of the corn ration by the addition 

 of corn oil. It would seem, therefore, that, while the results 

 in the two periods this year are not in exact agreement, they 

 nevertheless in a general way support the conclusion which 

 has previously been tentatively suggested, viz. : that, unless 

 the fat content of the ration is relatively high, the more 

 starchy foods are not sufficient to produce a satisfactory egg 

 yield, and the product falls below that obtained from feed- 

 ing a ration higher in protein. 



3. The fowls in houses Nos. 5 and 6 received rations in 

 both cases characterized by low protein, high ash and high 

 fat content. The deficiency in fat in the grains selected was 

 made up by the use of corn oil mixed with the meals used in 

 the mash, as in the other experiments. The fowls in house 

 No. 5 were fed grains, including oats and oat feed, charac- 

 terized by a high proportion of fiber. Those in house No. 6 

 were fed grains among which rice, which is characterized by 

 a very low percentage of fiber, was prominent. The object 

 in this experiment was to get light regarding the influence 



