THE USE OF CHICKS IN VITAMINE TESTS. 



R. J. Seymour and E. P. Durrani. 



The animals most frequently used for tests on vitamines 

 have been rats, mice, chickens and pigeons. While these 

 animals may possess some advantages yet their use also presents 

 some difificulties in the average laboratory. Rats and mice must 

 be kept well past the suckling stage in order that feeding tests 

 may be made. For such tests pigeons and chickens must be 

 kept in larger numbers and in more commodious quarters than 

 are usually available. Such disadvantages led to the trial of 

 chicks for the purpose of demonstrating to the classes in ele- 

 mentary physiology the role of vitamines in a diet. Chicks 

 were chosen for the test largely because no special cages were 

 necessary, because the rate of growth in the chick is rapid, and 

 the amount of care and attention required is slight. 



Because of their reputed hardiness Leghorn chicks were 

 selected. They were purchased as "day-old" chicks (available 

 at almost any season) and were placed in a suitable attic room, 

 heated by hot water and with a large skylight. No attempt 

 was made to keep the temperature constant, although the range 

 was not great usually being between 65° and 75° F. ; however, 

 the chicks could hover in an enclosed box beneath the hot 

 water pipes. Until they were a week old additional warmth 

 was supplied by an electric bulb. Water, shell, and grit were 

 constantly available. Foods containing practically no vitamines 

 were placed in a self feeder and all chicks had access to this at 

 all times. Such food consisted of rice flour, highly milled corn 

 meal, and patent or highly milled wheat flour. These were 

 presented to the chicks in a variety of ways and combinations. 

 The more usual method being to have these flours baked intO' 

 small unleavened loaves which were then dried and ground into 

 crumbs. The only care found necessary in carrying out the 

 test was to see that the food combinations were changed 

 frequently enough that the chicks continued to eat freely of the 

 food offered. 



At the beginning of the test the chicks were divided into 

 two lots of equal number and weight. One lot was marked by 

 means of aniline dye (red) on head and wings — the other lot 



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