PREVENTION OF PEROSIS BY CHOLINE

Abstract

A diet was described1 which produced a high incidence of perosis in young turkeys.The addition of manganese up to a level of 0.4 per cent MnSOa in the diet was found to have no preventive effect, but yeast gave partial protection.Recently Hogan, Richardson, and Patrick,2 working with chicks, have also described a situation in perosis occurring in the presence of manganese was prevented by an organic factor.In the present investigation a modification of the previous diet' was used, consisting of yellow corn-meal 65 parts, dried skim milk 15, washed casein 13, alfalfa meal 1, CaC03 3, KHzP04 1, NaCl (iodized) 0.5, MnS04 0.1, fish oil blend (3000-A, 400-D) 1 (Diet 161).Baby turkeys were placed on the diet at hatching and were observed at frequent intervals for perosis consisting of a distortion of one or both hock joints in lateral, medial, or anterior directions.Shortening and thickening of the bones of the leg, especially the tarsometatarsus, were accompanying symptIoms.Perosis was first noted after 8 to 12 days in birds on the basal diet, and the number of cases increased to reach a maximum at 20 to 30 days, by which time in some experiments all the birds were affected.On partially protective diets, symptoms appeared at, about the same time as in the case of the basal diet, and reached a maximum at about 20 days, after which the milder cases frequently retrograded and the hock joints became straight during the next 10 days.A test period of 28 to 35 days was used with ten to eleven birds in each group.It was found that the addition of a mixture of synthetic thi-