BY R. R. SLOCUM 75 



effect of carbonaceous and nitrogenous rations on egg yield, fattening and 

 the general health of the fowls. Another test of the same nature is the 

 comparison of a ration rich in vegetable protein with another equally rich in 

 animal protein. Proprietary feeds also have been given considerable 

 attention. 



DIGESTION EXPERIMENTS 



Few experiments have been carried on with the object of determining 

 the digestion coefficients of feed stuffs for poultry. One of the chief 

 reasons for this is the fact that such experiments are difficult because an 

 operation on the birds is necessary in order to separate the feces and the 

 excreta of the kidneys, which are normally voided together, in order to 

 make analyses of each separately. Other difficulties were the lack of 

 suitable equipment and the need of chemical assistance. It is just possible 

 also that poultrymen have not realized fully the importance and necessity 

 of such work. 



As a result of a lack of work of this character, our present feeding 

 standards for poultry are at best rather inexact. It is necessary in figuring 

 poultry rations to use the digestion coefficients established for other classes 

 of animals. This information is fundamental and before any exact feeding 

 tests can be carried on, it must be obtained. 



CRITICISM OF FEEDING WORK 



The feeding experiments which have been carried on in the past have, in 

 a majority of cases, been open in one or more particulars, to criticism of a 

 rather severe nature. Perhaps the most common weakness has been the 

 failure to recognize the importance of individual variation. As a result 

 conclusions have been drawn from comparisons in egg yield of pens com- 

 posed of only a few fowls. In using these small numbers it is quite possible 

 that the difference in egg yield has been the result not of the method of feed- 

 ing or of the feed but of the unequal division of individuals producing 

 either above or below the average. As the numbers used are increased the 

 chance of such unequal distribution of individuals is diminished and the 

 more nearly comparable are the two lots of fowls. Also the use of fowls 

 of unknown history may have been a source of considerable inaccuracy. 



Probably the second greatest criticism is the lack of repetition or the use 

 of an insufficient number of pens. A feeding experiment carried only 

 through a single year, or with only one lot of fowls may be affected by 

 climate or other factors which are not readily recognized and which 

 materially change the results. Under these conditions, the results are of 



