Biotin studies in pigs. 1. Biotin deficiency in the young pig

Sixteen pigs were given a purified diet of maize flour and casein from 5 to 25 d of age with or without a biotin supplement (100 micrograms/kg). From 26 to 94 d of age, eight of the pigs were changed to a wheat and casein diet with or without the biotin supplement and eight continued on the maize flour and casein diet. The weight gain and feed conversion ratio of the pigs were not affected by the dietary biotin supplement or the carbohydrate source. The pigs given the unsupplemented maize flour diet developed foot lesions, scaly skins and showed a reduction in carcass length. The excretion of biotin in the faeces was similar for the pigs given the biotin-supplemented and unsupplemented diets. The excretion of biotin in the faeces of pigs given the wheat diet was ten times as great as that of the pigs given the maize flour diet. The excretion of biotin in urine was 6 micrograms/d in the pigs given the unsupplemented maize flour diet and 67 micrograms/d in the pigs given the biotin-supplemented diet between 91 and 94 d of age. The biotin contents of the liver, heart, kidney, adrenals and plasma were increased by biotin supplementation of the maize flour diet. The 16:1/16:0 and 18:1/18:0 fatty acids ratios in the liver were decreased by biotin supplementation of the maize flour diet.