The Entry Rate of Trimethylamine and Its Deposition in Eggs of Intact and Cecectomized Chickens Fed Rations Containing Rapeseed Meal or Supplementary Choline

Abstract The kinetics of trimethylamine (TMA) metabolism have been studied in intact and cecectomized Rhode Island Red hens (which previously had been identified as tainters) fed a ration containing 10% rapeseed meal, using a single intravenous injection of 14 C-TMA. Mean entry rate, pool size, half-life, and plasma concentration of TMA in intact and cecectomized birds, respectively, were: 13 and 7 mg/day per kg body weight; 2797 and 921 μg; 97 and 63 min; and 443 and 212 ng/ml. Eggs from intact layers contained 5.2 μg TMA/g and were tainted with a fishy odor. Eggs from cecectomized hens were odor-free and contained only .06 μg TMA/g. When both groups were fed a wheat-soybean meal ration, all eggs were odor-free and contained only trace amounts of TMA (