Nov., 1938] Vitamin A Requirements of Growing Chicks 9 



a cheesy-like consistency was present in the corners of the eyes. Mor- 

 tality was very heavy\ The kidneys appeared grayish in color mth 

 swelling. The ureters were veiy much enlarged. 



Efforts to isolate from the kidnej^s and ureters crystals similar to those 

 found in the feces and in scrapings from the large intestine and caeca 

 were fruitless. 



Although crystals in the feces and intestinal scrapings were observed 

 in all cod liver oil groups from 4-12 weeks of age, none were found at 16 

 weeks of age. 



-.S'*^!' 



^ 



Microscopic c r y s - 

 tals observed in fecal 

 material and in scrap- 

 ings from intestines. 



Experiment B, 1932-33 

 Procedure 



An indication in last year's work on this project that there was an in- 

 creasing demand for vitamin A by growing chicks as they approach 

 maturity led us to include an additional experimental group (Group X) . 

 This group was fed a basal ration deficient in vitamin A plus varying 

 levels of cod liver oil of known vitamin A potency as the age increased. 

 For the first two weeks no addition of vitamin A through the medium of 

 cod liver oil was made. During the third and fourth weeks 1% of cod 

 liver oil was fed; 2% for the fifth, sixth and seventh weeks; and from 

 then to the end of the 12 weeks experimental period the level was in- 

 creased to 3%. 



In comparison with this group were five others which were handled in 

 the same way as last year. These groups being fed the basal ration con- 

 sisting of 140 pounds wheat bran, 140 pounds ground oat groats, and 70 

 pounds meat scrap, plus levels of standardized cod liver oil ranging from 

 0% to 3%. The group receiving the regular New England College Con- 

 ference ration was held as a check pen. 



In addition to these six groups of 50 New Hampshire Red chicks each, 

 it was thought desirable to compare the gro'ui:,!! of chicks being fed the 

 New England College Conference ration and those receiving this ration 

 minus the cod liver oil. By so doing, the value of this ration from a 

 vitamin A standpoint when lacking in cod liver oil could be roughly es- 

 timated. 



