The development of a biotin deficiency in domestic fowl given wheat-based diets.

1. Studies were done of the possible development of a biotin deficiency in domestic fowl of various ages as a result of feeding with diets composed mainly of wheat, and meat-and-bone meal. The degree of deficiency was estimated from physical symptoms, liver and kidney composition and hepatic enzyme activities. 2. Only a mild biotin deficiency developed in 3-week-old chickens and no adverse metabolic effect were found for chickens reared to 7 or 15 weeks of age or maintained for 9 months in lay on these diets, which were suspected of producing fatty liver and kidney disease in young chickens. At 3 weeks of age the deficiency was more severe the heavier the strain of chicken and the greater the rate of body-weight gain. 3. The present results question the supposition that biotin deficiency is the sole factor responsible for the development of fatty liver and kidney syndrome in young chickens.