March, 1938] Agricultural Research in N. H. 27 



Vitamin A Requirements 



Further studies of the vitamin A requirements for growing chicks 

 were made with four groups of five chicks each derived from a cross of 

 Barred Rock females with a New Hampshire male. 



The vitamin A concentrate was incorporated in Wesson Oil in a 

 homogeneous mass to provide solutions having a potency of 48, 98 and 

 158 International units per .4 cc. These solutions were then incor- 

 porated within the basal ration to provide 134.4, 274.4 and 442.4 Inter- 

 national units per 100 grams of total feed. Feed was mixed fresh each 

 week and kept tightly sealed in containers. 



The basal ration consisted of 46 lbs. ground white corn, 20 lbs. ground 

 wheat, 5 lbs. wheat bran, 15 lbs. dried skim milk, 10 lbs. meat scrap, 1 lb. 

 salt, 2 lbs. calcium carbonate and 1 lb. irradiated yeast (4,000,000 U. S. 

 P. units per pound). The control group received the basal ration only 

 with no addition of vitamin A. 



The investigators, A. E. Tepper and R. C. Durgin, conclude that for 

 rapid growth chicks with a normal storage of vitamin A upon hatch- 

 ing need during the first five-week period a total intake of approximate- 

 ly 134.4 International units of vitamin A per 100 grams of feed. Fol- 

 lowing this initial growth period the demands for vitamin A are in- 

 creased to approximately 400 units per 100 grams of feed. {Purnell 

 Fund) 



Individual Cage for Poultry Nutrition Studies 



In the development of chicken nutrition studies, need has been felt 

 for an individual chick cage (1) capable of brooding with low mortal- 

 ity, (2) capable of furnishing quarters for one chicken from baby 

 chick age to maturity, (3) so constructed that sanitation may be prop- 

 erly controlled, (4) containing a type of feeder which will allow a very 

 minimum of waste, (5) containing a dropping pan suitable for use in 

 the event of chemical feces examination and, (6) so proportioned and 

 constructed that a series of cages may be maintained with the least ef- 

 fort and minimum requirement of space. 



With these principles in mind, a cage was designed and built by A. E. 

 Tepper ; and in consultation with other members of the staff a new 

 feeder was designed with a small feed opening and "baffle" plates to 

 prevent feed waste. 



A two-year trial of these cages in connection with vitamin A studies 

 has proved their value. In all trials a livability of 100% to six weeks 

 of age has been obtained. Chicks can be maintained in these cages be- 

 yond the initial brooding period. Sanitation is controlled by remov- 

 able wire floors, a larger wire mesh floor being substituted after the first 

 three weeks. Metal dropping pans collect feces and are easily cleaned. 

 The feeder can be so managed as to provide a minimum of waste. 



For those who wish further construction details concerning these in- 

 dividual cages a set of complete plans is available. (Purnell Fund) 



Confinement vs. Open Range for Bronze Turkey Breeders 



To observe the effects of confinement of turkey breeders under the 

 stimulus of artificial lighting, two groups of Bronze turkeys were se- 



