The Vitamin A Requirements of Chicks with Observations on the Comparative Efficiency of Carotene and Vitamin A

Vitamin A Requirements of Laying Hens

“…per 100 grams of diet is accepted as a minimum level of vitamin A for normal chick growth to eight weeks of age (Record, Bethke, and Wilder, 1937), it can be stated that the unsupplemented hen basal diet contained definitely less than 80 i.u. per 100 grams (Tables 3 and 4).…”

The Stability of Vitamin A from Cod Liver Oil in Mixed Feeds

“…The irradiated dried yeast supplied 4,000 International Units of vitamin D per 100 grams of feed, which has been shown by Record, Bethke, and Wilder (1937) to be ample to meet the vitamin D requirements of chicks. The cod liver oil was diluted in cottonseed oil so that 1-percent oil additions were made in all lots.…”

The Stability of Carotene and Vitamin A in a Mixed Ration

“…The levels of vitamin A and carotene selected represented slightly subminimum to slightly above minimum requirements, based upon previous work (Record, Bethke, and Wilder, 1937). The cod liver oil and alfalfa leaf meal werje each added at three different levels to the basal ration.…”