Transfer of Dietary Sulfadimethoxine and Sulfamonomethoxine into Eggs and Their Disappearance from Eggs

Sulfadimethoxine (SDM) and sulfamonomethoxine (SMM) were fed to laying hens for 3 weeks at dietary levels of 0, 25, 50 and 100ppm. Thereafter the drug-free diet was fed to all hens for another 2 weeks.Concentrations of SDM in egg yolk and albumen increased rapidly after feeding SDM, reaching plateau levels on the 9-12th day, and 6-12th day, respectively. After the withdrawal of dietary SDM, SDM in egg yolk and albumen decreased to below the detection limit on the 7-8th day and 3rd-5th day, respectively.Concentrations of SMM in egg yolk and albumen increased rapidly after feeding SMM and reached plateau levels on the 5-6th day. After the withdrawal of dietary SMM, SMM in egg yolk and albumen decreased to below the detection limit on the 5-8th and 3rd-4th day, respectively.