Biotin studies in pigs. 2. The biotin requirement of the growing pig

Twenty pigs weaned at 5 d were given pelleted diets based on maize flour and casein and supplemented with 0, 50, 100, 150 or 200 micrograms biotin/kg diet. The performance of the pigs was not influenced by the biotin content of the diets. Typical biotin deficiency symptoms (foot lesions and skin pustules) were observed in pigs given the unsupplemented diet and the diet supplemented with 50 micrograms biotin/kg diet. Tissue biotin concentration plateaued when 100 micrograms biotin/kg was added to the diet. Faecal biotin excretion was independent of dietary biotin intake, but increased with age. Urine biotin excretion at 102 d was significantly lower for the unsupplemented pigs than for the pigs given various levels of dietary biotin supplements. A dietary requirement of biotin for young pigs between 50 and 100 micrograms/kg diet is suggested from the results of the present experiment.