The effects of different levels of dietary biotin on the performances and on bone growth in the broiler

Abstract

Biotin deficiency in the broilers' diet causes reduction of growth rate and food conversion, clinically the appearance of cutaneous lesions that are particularly severe around the beak and in the plantar regions, and long bone deformities (Anderson and Warnich, 1970; Riddel, 1981; Bain et al., 1989). It has been demonstrated that 21-day old chicks fed biotin deficient diets showed thickening of the tibiotarsus cortex. (Watkins et al., 1989). In order to avoid nutritional disorders and to ensure the “optimal” dosage, broiler biotin requirements are still undefined. Biotin is found in both animal and vegetal tissues in small quantities and in variable amounts; this is due to intrinsic factors in the feed (biotin binding protein) and to extrinsic factors like technologic processing, that limit biotin availability...