乃卡巴精(Nicarbazin)為我國可用於肉用家禽之飼料添加物，用於預防艾美屬(Eimeria)球蟲引起的球蟲症(coccidiosis)，但不可用於蛋雞產蛋期，近年倡議經濟動物福祉，蛋雞放牧飼養可能引來球蟲症，導致乃卡巴精使用於蛋雞的可能性逐漸被關注。為符合動物福利，罹病之雞隻仍應予以治療，投藥過程中所產出之雞蛋均有藥物殘留風險，依法不得供人類食用。本研究於蛋雞飼料中添加每公斤飼料含5ppm、60ppm、120ppm乃卡巴精，飼養七天後停藥，並恢復正常飼料供應，以LC-MS/MS觀察乃卡巴精於蛋雞肝臟、血液、肌肉及雞蛋中殘留情形，訂定適合的停藥期，使痊癒之蛋雞才可返回產蛋雞群重新生產。結果顯示停藥2週後60ppm組與120ppm組之肝臟仍可驗出殘留；120ppm組雞蛋在停用乃卡巴精後第16天不再被檢出。60ppm組雞蛋在停用乃卡巴精後第13天不再被檢出。5ppm組雞蛋在停用乃卡巴精後第10天不再被檢出，顯示國內禁用於產蛋期蛋雞為合理策略，做為治療用途應至少停藥3週以上。
Nicarbazin is a feed additive for poultry in Taiwan. It is used to prevent coccidiosis caused by Eimeria coccidia, but it is not allowed to be used in laying hens. Laying hens may face coccidiosis due to the grow of animal welfare that bring in more free rage farms and barn type farms. For animal welfare, sick chickens should still be treated. Eggs produced during the dosing process are at risk of drug residues and are not allowed for human consumption in accordance with law. In this study, different levels of nicarbazin were added to the feed then were withdrawn after 7 days of feeding. LC-MS/MS was used to observe the residues of nicarbazin in liver, serum, muscle and eggs of laying hens to establish a suitable withdrawal period so that the cured hens can return to egg production. The nicarbazin in the liver was still detectable after two weeks in 60ppm and 120ppm groups. In the 120ppm, 60ppm and 5ppm groups of the experiment, nicarbazin was still detectable after 16, 13, 10 days of drug withdrawal, respectively. In conclusion, this study shows that the ban of using nicarbazin in laying hens is a reasonable strategy. It is suggested that in case of the therapeutic purpose, at least a 3 weeks withdrawal period should be allowed.
