Conditions necessary for a response by the commercial laying hen to supplemental choline and sulfate.

An experiment was conducted with commercial laying hens, 24 wk of age, to study the response from adding 440 mg of choline and sulfate as 2 g of K2SO4 per kg of a corn soybean-meal diet containing different levels of supplemental DL-Met. The basal diet was formulated to be deficient (.495%) in sulfur amino acids, and nonsulfate forms of trace minerals were used in all diets. The experiment was conducted for 22 wk; however, only the data from the last 12 wk were used as the measurement of response since the responses were greatest during this period. Egg production, egg weight, and feed efficiency were improved with each addition of Met from 0 to .2%. Choline supplementation of the diet containing added .033% Met significantly increased egg production. However, no response was obtained from choline supplementation of diets containing 0 or .067% added Met. Addition of sulfate improved egg production when it was added to the diet with choline but not when it was added to the diet with Met.