Choline-Methionine Interactions in Young Swine

Two experiments were conducted to study choline-methionine interactions in young swine. Seventy-two pigs in three replicates and 144 pigs in four replicates were utilized in Experiments 1 and 2, respectively. The factorial design of both experiments included 0 and 330 mg/kg dietary choline. Methionine levels of .12% and .32% in Experiment 1 and of .32%, .52% and .72% in Experiment 2 were used. Methionine supplemented pigs gained faster (P<.01) and were more efficient (P<.05), and choline supplemented pigs gained faster (P<.01) and had a higher hematocrit (P<.05) in Experiment 1 than controls. Methionine supplementation increased daily gain (P<.01) (.72 >.32) or (P<.05) (.32 >.52) and decreased plasma urea (P<.05) (.72 <.32 = .52) in Experiment 2, with a trend toward a similar choline effect in both criteria. There were no differences in plasma triglycerides, plasma cholesterol, plasma alkaline phosphatase or plasma urea in Experiment 1. Gross and histological examination of tissues and organs (liver, kidney, spleen, heart, lung, brain, skeletal muscle, thyroid, adrenals, thymus, bone marrow, joints, gastro-intestinal system) of 12 necropsied pigs (three per treatment) of Experiment 1 revealed no differences. There were no differences in feed intake, feed conversion, or hematocrit in Experiment 2. Neither experiment showed differences in hemoglobin, hematocrit:hemoglobin ratio, plasma total phospholipids or plasma phosphatidylcholine. There was no choline-methionine interaction. These results showed that choline supplementation is required in an 11% protein, semi-purified diet (.13% cystine) when .32% methionine was present.