Proceedings of Seventeenth Nokmal Institute 225 



feed which has been used in digestion experiments most widely, 

 namely, corn. Comparing the percentage of protein that is digested 

 from corn, we find the average from sixteen trials with poultry 

 to be 81.5 per cent; the average from twelve trials with cattle 

 to be 76 per cent; and the one trial with swine to be 69 per cent. 

 Next let us compare the trials with wheat : Protein digested from 

 wheat with ten trials by poultry averaged 75 per" cent; with four 

 trials by cattle 74 per cent ; and with an unknown number of 

 trials by swine 80 per cent. From these instances it would 

 .appear that poultry digest protein more nearly like cattle than 

 like swine. 



Comparing the percentage of the nitrogen-free-extract digested 

 from these feeds, we find with corn, poultry 91 per cent; 

 cattle 93 per cent; swine 89 per cent: with wheat, poultry 

 87 per cent; cattle 93 per cent; swine 83 per cent. In other 

 words, poultry are about midway between swine and cattle in 

 their ability to digest nitrogen-free-extract. 



Comparing the percentage of the fat digested from these feeds, 

 we find with corn, poultry 88 per cent; cattle 86 per cent; 

 swine 46 per cent: with wheat, poultry 53 per cent; cattle 71 

 per cent; swine 70 per cent — a rather wide variation, but the 

 balance in favor of the likeness of poultry to digest fat similar 

 to cattle. And so we might enumerate for other feeds, finding 

 many exception, but nevertheless, as will be shown by 

 the summary of averages, a tendency toward a likeness of poultry 

 to digest more nearly like cattle than like swine. 



It is true that the average is not the most conclusive proof, 

 since we want the digestion of individual feeds, but the average of 

 the percentage of nutrients digested by poultry, cattle and swine 

 for the same feeds will at least be comparable, which is the object 

 desired. Three general averages have been taken. First there 

 is given the average percentage of the nutrients digested by each 

 group of animals when all the feeds listed are considered ; namely, 

 sixteen different feeds for poultry, representing a total of seventy- 

 four trials; fifteen different feeds for cattle representing a total 

 of one hundred and thirty-one trials; and eleven feeds for swine 

 representing a total of thirty-three trials. This, it must be re- 

 membered, is an average from feeds not common to each group, 

 II — 8 



