Available biotin content of various feed ingredients.

The availability to the chick of the microbiologically determined biotin in various feed ingredients was assayed using a standard curve methodology. The chicks were grown up to 28 days of age. Ingredients of the standard diet were partially replaced by the test ingredient. Each test mixture was also supplemented with 200 micrograms biotin/kg and fed to a control group. The percentage of growth of the test chicks compared with the controls proved to be a suitable parameter for the assessment of biotin availability. Availability of biotin was expressed in percentage of the biotin determined microbiologically. In the tested cereals availability was distinctly low, whereas in some other feed ingredients the availability was reduced less.