Failure of Excess Glycine to Aggravate Choline-Deficiency Perosis in the Young Chick

Early work on the enlarged hock disorder (i.e., perosis) in young chicks (Jukes, 1941a,b) and poults (Scott, 1950) suggested that excess levels of dietary glycine or its precursors may accentuate the incidence and severity of this condition. These observations together with those wherein a casein-gelatin diet (high in glycine) has been implicated as causative (Nelson and Scott, 1953) suggested that the effect of glycine on choline-deficiency perosis needed reevaluation. Though perosis is an extremely complex condition that can be produced experimentally by an inadequate intake of several different nutrients, it is generally recognized that the syndrome occurs with greatest rapidity when resulting from an inadequate intake of choline (Scott and Netke, 1969). The assay presented in Table 1 was designed to assess the effects of graded levels of dietary glycine, ranging from deficient to superadequate, on growth rate and incidence of perosis in young chicks fed a choline-free purified diet.…