30 N. H. Agri. Experiment Station [Bui. 296 



Vitamin "A" Requirements of Growing Chicks 

 at Various Stages of Development 



To determine the Vitamin A requirements of growing chicks in terms 

 of Vitamin units for optimum weight gains and high livability, twenty- 

 pedigreed sex-linked pullet chicks were maintained in individual cages 

 over a six week period. The twenty chicks were equally divided into 

 f.ve groups and fed rations of varying Vitamin A content as follows: 



Group 1 — Basal Ration (Deficient in Vitamin A) 



Group 2— Basal Ration plus oral feeding of 33 U.S.P. x (1934) A 

 Units daily. 



Group 3— Basal Ration plus oral feeding of 99 U.S.P. x (1934) A 

 Units daily. 



Group 4— Basal Ration plus oral feeding of 165 U.S.P. x (1934) A 

 Units daily. 



Group 5 — New England College Conference Formula 



The results secured over the six weeks feeding period substantiate 

 the following statements, report A. E. Tepper and R. C. Durgin. {Pur- 

 nell Fund) 



1. Increased Vitamin A consumption tends to increase feed con- 

 sumption. 



2. There appears to be a relatively hifih Vitamin A requirement dur- 

 ing the initial starting period. 



3. The Vitamin A consumption per 100 grams of feed consumed for 

 most economical results should be at least 108 U.S.P. x (1934) 

 units. {Purnell Fund) 



Technique for the Eradication of PuUorum 



A comparison of the efficiency and accuracy of the whole blood stain- 

 ed antigen test for pullorum and the standard tube test was made by 

 C. A. Bottorff in twelve flocks selected on their history of possible in- 

 fection. There were 15,304 birds tested and only 63 reactors were found 

 — one in one flock and 62 in another. The owner of the flock having the 

 large number of reactors decided against additional testing. In this one 

 case, the whole blood method picked out 42 reactors, and the standard 

 tube test 62 reactors. The remaining ten flocks all passed negative. 



As a result of this work, it is recommended that the standard tube 

 test continue to be used for the official test in New Hampshire. 



Control of Coccidiosis 



Studies were made of various parts of the chicken's digestive tract to 

 determine the normal pH and the influence of feeding different alkalis 

 and acids. No variations of significance in the study of coccidiosis, how- 

 ever, were found. 



