MAEKET COLD-STORAGE CHICKENS. 61 



Zaitscheck concludes that the food has influenced the composition 

 of the fat, the fowl on the corn and milk ration showing values nearer 

 those of butter fat than the results found for the chicken fed on corn 

 alone — an observation, which, if borne out by further experimenta- 

 tion, is of considerable physiologic interest. 



As is to be expected from the small number of analyses recorded 

 a lack of harmony in technique, and in the use of fowls of unknown 

 age, breed, and previous history, there is a wide variation in results. 

 That the analyses of the flesh of animals so highly organized as are 

 chickens should have an exact and fixed composition is scarcely to be 

 expected, even when breed, food, age, and the length of time between 

 killing and examining are the same. That very wide differences do 

 occur when such factors as have been mentioned are not taken into 

 account is not only reasonable, but has been demonstrated by cer- 

 tain analyses given later in this report. 



SELECTION OF MATERIAL FOR STUDY. 



Since the work which has been undertaken is a comparison of the 

 flesh of chickens kept by the aid of low temperatures for varying 

 lengths of time, it is necessary that there should first be an acquaint- 

 ance with the composition of fresh fowls of known history and of 

 the breeds commonly found in the markets. The species most fre- 

 quently kept for food purposes in the Middle States are the Plymouth 

 Rock (white and barred), White Wyandotte, Rhode Island Red, and 

 Leghorn. The last-named species is especially valuable for egg pro- 

 duction. The birds are too small and the breast muscles are not 

 sufficiently well developed to render them as desirable for market 

 purposes as are the other breeds, but because of their laying quali- 

 ties they are fairly plentiful, and young cocks and old hens are there- 

 fore killed off and sold for food. 



As the cold-stored fowls which are to be discussed were taken 

 from regular market stock and are, almost exclusively, of the Plym- 

 outh Rock variety, or its crossbreeds, the discussion of the compo- 

 sition of fresh chickens will be limited accordingly. 



The birds kept for standards of comparison were fed chiefly on 

 Indian corn, milk, and clean table scraps. They were regularly and 

 abundantly fed, were supplied with pure water, and their runs were 

 placed in an orchard having a southern exposure, this environment 

 insuring rapid growth and tender flesh. For 24 hours previous to 

 killing all food was withheld, but water in plenty was provided. 

 They were killed by puncturing the spinal cord by way of the mouth, 

 and were bled well, dry picked, and the animal heat was quickly 

 extracted. They were kept for from 18 to 24 hours at the tempera- 

 ture of an ordinary refrigerator before the analysis was begun, that 

 being the period required for a frozen chicken to thaw in a house 

 refrigerator. All were undrawn. 



