The influence of fluctuating water temperature and dietary oxytetracycline (OTC) at 0 (0X), 80 (1X), 240 (3X), 400 (5X) and 800 mg (10X)/kg biomass/day for 30 consecutive days on the safety of monosex (all male) Nile tilapia Oreochromis niloticus fries in terms of feeding, growth, survival and histopathology of vital organs were assessed. A dose-dependent decline in feed intake and biomass was recorded. The OTC-dosed groups recorded higher mortalities than the control. The therapeutic OTC-dosing (1X) in conjunction with low temperature caused 75.56 ± 8.01% mortality and 25.75% reduced feed intake in 30 days. The mortalities increased with increasing OTC-doses from 85.19 ± 3.39% (1X) to 95.56 ± 2.22% (10X) and fluctuating temperature (12.00–21.50°C) even after the withdrawal of OTC. Relatively mild to moderate histopathological lesions were observed in the kidney, liver and intestine of OTC-dosed fries. These results suggested that dietary OTC and low water temperature may cause adverse effects on monosex O. niloticus fries.

连续 30 天在 0（0X）、80（1X）、240（3X）、400（5X）和 800mg（10X）/kg 生物量/天的水温波动和膳食土霉素（OTC）对安全性的影响单性（全雄性）尼罗罗非鱼Oreochromis niloticus对鱼苗的摄食、生长、存活和重要器官的组织病理学进行了评估。记录了饲料摄入量和生物量的剂量依赖性下降。OTC 给药组的死亡率高于对照组。治疗性非处方药 (1X) 与低温相结合，在 30 天内导致 75.56 ± 8.01% 的死亡率和 25.75% 的采食量减少。死亡率随着 OTC 剂量从 85.19 ± 3.39% (1X) 增加到 95.56 ± 2.22% (10X) 和温度波动（12.00–21.50°C）而增加，即使在停用 OTC 后也是如此。在 OTC 剂量的薯条的肾脏、肝脏和肠道中观察到相对轻度至中度的组织病理学损伤。这些结果表明膳食OTC和低水温可能对单性尼罗罗非鱼薯条产生不利影响。