Prevention of Perosis by Biotin. ∗

Abstract

Perosis was reported 1 to be a symptom accompanying the egg white syndrome in chicks. In the present investigation, single-comb White Leghorn chicks were placed on the following diet at hatching: Yellow corn meal, 55 g; wheat middlings, 20; dried skim milk, 10; commercial casein, 10; ground limestone, 2; steamed bonemeal, 2; alfalfa meal, 1; choline chloride, 0.1; NaCl, 0.5; MnSO₄, 0.05; fresh raw egg white, 30 cc. The wet mixture was spread in thin layers and dried at 45°C, after which 0.3 g of fish oil blend (3000-A, 400-D) was added. In addition to dermatitis, 2 symptoms of perosis developed in from 50 to 70% of the chicks at the age of 3 to 5 weeks. If egg white was omitted from the diet, or if cooked egg white replaced raw egg white, perosis did not develop. It was found in a preliminary experiment that all the symptoms were prevented by injecting a biotin concentrate† at a level which supplied approximately 3 μg of biotin daily. In the next experiment, crystalline biotin methyl ester‡ was injected into the breast muscle. Each chick received a total of 13 μg divided into 7 injections during a period which extended from the 12th to the 32nd day. Eight chicks were used in the injected group and 11 uninjected chicks served as controls. The results shown in Table I were observed on the 38th day.

Feathering was superior in the injected group. The level of biotin administered, which averaged only 0.34 μg per bird per day for the duration of the experiment, was not sufficient to prevent dermatitis completely but was sufficient to prevent perosis.