72 EXPEEIMENT STATION RECORD. 



weatlier conditions varied, depending upon the season and the territory in- 

 volved. In all of the work commercial surroundings and commercial routine 

 prevailed. Thermographs, or self-registering thermometers, were used to 

 record the car temperatures throughout the entire transit. When the ear was 

 opened for unloading, a laboratory examination was made of samples of the 

 fowls, by estimating the amount of ammoniacal nitrogen in the muscle tissue, 

 as an index of the progress of flesh changes, and the amount of free acid in 

 the fat, since the rise in acidity is an indication of the aging of the whole 

 carcass. 



Fresh chickens contain about 0.0110 per cent of ammoniacal nitrogen. It 

 was found that poultry shipped under car temperatures of from 18 to 26° F. 

 showed 0.0120 per cent ammoniacal nitrogen; under 27 to 30", 0.0122 per cent; 

 31 to 34°, 0.0131 per cent; and 35 to 39°, 0.0141 per cent. This difference in 

 composition at the end of the railroad haul continues with increasing magni- 

 tude throughout the period at the wholesale commission house and at the re- 

 tailer's, while in the commission house the deterioration in the high tempera- 

 ture shipments is always at least one stage ahead of the low temperature 

 shipments. It is evident that even such excellently handled poultry as com- 

 prised these experimental shipments, if exposed to unfavorable temperatures 

 during transportation, receive an impetus toward decay that can not be over- 

 come by subsequent irreproachable treatment on the market. 



The results indicate that the most favorable temperature for poultry trans- 

 portation is less than 31° F. The problem of maintaining this temperature is 

 largely a question of car construction. The -many different cars used in these 

 shipments furnished a great variety of sizes, insulations, roofs, doors, ice 

 bunkers, and other elements which are factors in the sum total of eflBciency. 

 In calculating the relative efficiency of the cars, a formula was devised which 

 would take into account the various factors of icing, surface exposure of the 

 car, atmospheric temperature, inside temperature, length of time in transit, etc. 

 The insulation of the car in relation to temperature appeared to be its most 

 vulnerable and its most important part, the construction of the ice bunker 

 coming next in importance. Certain types of insulation in the side walls and 

 floors of the cars were found to be preferable to others. The cars with the 

 best insulated and best built roofs proved to be the most efficient. Moist floors 

 were found to be a serious defect in the present construction of cars. 



The wire basket type of bunker is thought to be the most efficient, since an 

 abundant air access to ice and salt results in increased efficiency. Likewise 

 the holding back of the brine in the tank bunker increases the ability of the 

 bunker to chill the car and hence results in increased efficiency. These and 

 other points in construction are regarded as the essential features of the most 

 efficient refrigerator car of the future. 



DAIRY FARMING— DAIRYING. 



A comparison of first, second, and third crop alfalfa hay for milk pro- 

 duction, W. E. Carroll {Utah Sta. Bui. 126, pp. 153-1S9).— In view of the 

 popular disfavor toward second crop alfalfa as a feed for dairy cattle, experi- 

 ments were conducted during 2 seasons, 1911-12, and 1912-13, with first, second, 

 and third crops of alfalfa to determine the relative value of these crops. In 

 these experiments the alfalfa was fed ad libitum, with a grain mixture of 

 O.Go lb. daily to each cow per pound of milk fat produced per week. The test 

 periods were from 3 to 4 weeks' duration, and the feed unit system was 

 adopted. 



