Published online by Cambridge University Press: 27 March 2009
Studies on the feeding of cyclized vitamin A, vitamin-A alcohol, and vitamin-A ester (as cod-liver oil) to chicks receiving a diet of c. 13% protein content, show that chicks do not assimilate cyclized vitamin A and only begin to assimilate vitamin-A alcohol and vitamin-A ester between the 35th and 42nd day, when the results of analytical methods employed to evaluate carcass and liver stores of these substances are used as criteria, or when growth is used as criterion.
Studies on the feeding of green food and yellow maize, as sources of provitamin A, and vitamin-A alcohol, to chicks receiving a diet of c. 17% protein content, show that chicks do not utilize these substances until between the 35th and 42nd day, when the results of analytical methods are employed as criteria of assessment of vitamin A storage in carcass and liver, or when growth is used as criterion.