﻿REFRIGERATION OF DRESSED POULTRY IN TRANSIT. 5 



SHIPMENT OF POULTRY. 



PREPARATION. 



The dressed poultry used in this investigation was prepared for 

 shipment in modern poultry packing houses equipped with mechanical 

 refrigeration. The birds varied in size, some being broilers, some 

 roasters, and some fowls or stewing chickens. Killing was done by 

 cutting the jugular vein in order to drain the carcass of blood, then 

 puncturing the brain to paralyze the feather muscles and destroy life. 



The poultry was dry picked according to the usual commercial 

 methods, special care being taken to select only those birds with 

 sound skins to obviate the nonuniformity which might be introduced 

 by torn and rubbed skins. Immediately after dressing, the birds were 

 placed in chill rooms cooled by means of mechanical refrigeration to 

 32° F. (0° C), where they were held for 24 hours to remove all of the 

 animal heat. A thermograph registered the temperature changes 

 during chilling. The birds, chilled to 32° F. (0° C.) or less throughout, 

 were then packed in boxes, one dozen to the box. The packing was 

 done in a chilled room, where the boxes remained until they were 

 loaded into the refrigerator car with the usual commercial carload 

 shipment of dressed poultry. 



LOADING. 



The cars were iced 24 hours before loading, the percentage of salt 

 added varying from 5 to 15 per cent, depending upon the weather. 

 The temperature of the car midway between the door and the end 

 was recorded at that time and again when the loading was finished 

 and the car closed. Records were also kept of prevailing atmos- 

 pheric conditions. Thermographs, or self-registering thermometers, 

 which made a complete record of the temperature during the entire 

 transit period, were placed in the car, one near the floor next to the 

 bunker to record the air temperature in the coldest part of the car, 

 and another at the top of the load near the center of the car to furnish 

 a similar record for the warmest part of the car, that is, warmest in 

 warm weather, but, on account of loose doors and poor insulation, 

 perhaps not as warm as some other parts of the car in extremely cold 

 weather. The boxes of poultry to be examined chemically were in 

 juxtaposition to one of these thermographs. The period of transit 

 varied from 5 to 10 days and in almost every case was concluded in 

 New York City. 



CHEMICAL ANALYSIS. 



When the car was opened for unloading, a sample from three fowls 

 was selected from the experimental packages and subjected to the 

 laboratory examination. This consisted in estimating the amount 

 of ammoniacal nitrogen x in the muscle tissue, which is an index of 



i Pennington and Greenlee. An application of the Folin method to the determination of ammoniacal 

 nitrogen in meat. J. Amer. Chem. Soc, 1910, 32 (4): 561. 



