A CHOLINE deficiency is readily produced in chicks by feeding a diet low in choline or certain choline precursors. The effect of choline deficiency in laying hens, however, is less clear. McCollum et al. (1912) fed a diet containing 70 parts ground polished rice previously extracted with hot alcohol and 30 parts of dried skimmed milk to laying hens and found that more lecithin was present in eggs produced by these hens than had been consumed in the diet. Therefore, these investigators concluded that large amounts of lecithin were synthesized by laying hens.Abbott and DeMasters (1940), using a diet similar to McCollum's supplemented -with other vitamins, found that addition of choline to this basal diet increased egg production, prevented weight loss, and reduced liver fat.When diets have been studied which were low in methionine and vitamin B 12 , good responses were obtained from the addition of choline to diets for laying hens. Welch and Couch (1955) showed that a basal diet low in B i2 and methionine was improved by the addition of choline, provided that homocystine was present. Vitamin B 12 and homocystine supplementation would also improve this diet.Burns and Ackerman (1955) reported that choline deficiency in the laying hen <:ould be produced in the absence of dietary at Columbia University Libraries on March 24, 2015