322 POULTRY PRODUCTION 



poultry."! This is because the so-called urine contains the 

 broken-down tissue from the body, which cannot be dis- 

 tinguished from the undigested portions of the food by 

 present analytical methods. 



The white, pasty material appearing in the droppings of 

 birds is uric acid, excreted by the kidneys. This increases 

 in amount as the ration becomes more nitrogenous. The 

 droppings of wild birds living almost entirely upon worms and 

 insects are quite white. 



Table XXIX. — ^Avebage Digestion Coefficients of the 

 Nutrients with Chickens." 



No satisfactory method of separating the urine from the 

 feces has been generally adopted. Some successful work 

 has been done by means of a surgical operation, whereby a 

 false urinary aperture has been made. In very few cases, 

 however, do the birds operated upon return to apparently 

 normal health so that the results of the trials are trustworthy. 

 The digestive coefficients of the three organic nutrients for 



' Brown, Bureau of Animal Industry, Bulletin No. 56. 

 2 Rearranged from Bartlett, Maine Bulletin No. 184, who secured the 

 'data from various sources. 



