Nov., 1938] Vitamin A Requirements of Growing Chicks 13 



Experiment C— 1933-34 



Procedure 



This experiment involved the use of eleven groups of 50 New Hamp- 

 shire Red chicks, or a total of 550 chicks. The test groups were fed in 

 growing batteries as follows: 



1. Basal ration — deficient in vitamin A 



140 pounds wheat bran 

 140 " ground oats 

 45 " meat scraps (50% protein) 



2. Basal + 1% cod liver oil 



3. Basal + 2% cod liver oil 



4. Basal -\- 3% cod liver oil 



5. 4-12 week control 



(25 chicks from Group 9 were removed at end of four-week period 

 and fed only basal ration from then till end of period.) 



6. 8-12 week control 



(25 chicks from Group 9 were removed at end of eight-week period 

 and fed only basal ration from then till end of period.) 



7. Basal ration for first two weeks and then basal ration plus 1% cod 



liver oil. 



8. Basal ration plus 1/2% sardine oil. 



9. New England College Conference ration (check group). 



All chicks were wingbanded and weighed individually by weekly 

 periods with sex notation being made as soon as possible for subsequent 

 weight and gro\\'th analyses. Feed consumption was recorded weekly. 

 All mortality was tabulated and autopsy records preserved for analysis. 



Groups 1 to 8 inclusive were treated daily with ultra-violet light for a 

 period of 15 minutes at 30 inches distant. This provision was made to 

 furnish a supply of vitamin D to all groups above their normal require- 

 ments. 



Group 8 was used to determine the relative amount of vitamin A in 

 sardine oil and its ability to prevent the occurrence of opthalmia. 



Discussion 



Group 1 showed materially slower growth and presence of a vitamin A 

 deficiency was noted in all chicks but one. Swelling of the eye and some 

 indications of watery eyes were present at four weeks of age. A few 

 chicks which died between nine and ten weeks of age exhibited heavy 

 urate deposits over kidneys which were themselves grayish in color. 

 Nodules in throat and esophagus were found in two chicks upon autopsy. 



Groups 2, 3 and 4 showed very little difference in weight gains indicat- 

 ing that the 1% cod liver oil supplied sufficient vitamin A both for pre- 

 vention of opthalmia and optimum growth. Additional amounts were not 

 used more efficiently when comparing growi:h and freedom from vitamin 

 A deficiency. 



Group 9 (check) receiving the New England College Conference ration 

 weighed at the end of the twelve-week period 2.897 pounds per chick 

 average. This was approximately one-half pound heavier average per 

 chick than the 1, 2, or 3% cod liver oil groups on basal ration. 



The 4-12 week control group, No. 5, showed continued normal gains up 



