日粮添加活性炭对罗非鱼生长性能、抗氧化及环境重金属耐受性的影响

Effects of supplementation of active charcoal on growth performance,antioxidation and resistance to environmental heavy metals of tilapia

文章旨在研究日粮添加活性炭对罗非鱼生长性能、抗氧化、体成分及对环境重金属耐受性的影响。试验选择均重为(14.5±0.55)g的罗非鱼600条,随机分为10组,每组4个重复,每个重复15条鱼。试验采用5×2多因素方差设计,共设0、2、4、8和16g/kg活性炭5种日粮,环境分为重金属(铅、镉、铜和锌)条件和非重金属条件,试验共进行8周。结果显示:日粮添加16g/kg活性炭组水中游离氨水平最低(P<0.05)。随着日粮活性炭添加水平的升高,罗非鱼生长和采食量显著升高(P<0.05)x,但超过8g/kg时开始降低。在环境重金属条件前,16g/kg活性炭组显著提高了血浆葡萄糖水平(P<0.05),显著降低了总蛋白和总脂肪含量(P<0.05);环境重金属条件下显著降低了蛋白和脂肪含量(P<0.05)。罗非鱼暴露在重金属环境条件下,对照组显著提高了血浆SOD、CAT和GSH-Px活力,同时显著降低了MDA含量(P<0.05)。暴露后,对照组显著提高了各元素在机体的沉积量(P<0.05),且随着日粮活性炭添加水平的升高,机体重金属含量显著降低(P<0.05)。结论:日粮添加活性炭可以提高罗非鱼的生长性能和饲料利用率,其中活性炭的适宜添加水平为8g/kg,同时活性炭可以提高罗非鱼的抗氧化性能,降低机体重金属的沉积。

This study aimed to study the effects of supplementation of active charcoal on growth performance, antioxidation and resistance to environmental heavy metals of tilapia. A total of 600 tilapias with the average body weight (14.5±0.55)g were allotted to 10 groups with 4 replicates of 15 tilapias. The trial was designed by multi-effects, 5 levels of active charcoal(0, 2, 4, 8 and 16 g/kg),and 2 condition(with or without heavy metals exposure). Results showed that ammonia concentrations were significantly adversely(P < 0.05)affected by active charcoal supplementation and lowest ammonia concentration was observed at 20 g/kg. Fish growth and feed intake increased significantly as dietary active charcoal levels increased up to 8 g/kg diet after which fish growth declined and lowest fish growth was obtained with fish fed on the control diet(P < 0.05). Before heavy metal exposure,plasmatic glucose increased,whereas plasmatic total protein and total lipids decreased significantly in fish fed 16 g/kg active charcoal(P < 0.05). After heavy metal exposure,lowest values of plasmatic total protein and total lipids were observed in fish fed the control diet(P < 0.05). Before heavy metal exposure, GSH-Px activity was significantly higher in fish fed 16 g/kg active charcoal than the control fish(P < 0.05). In conclusion, dietary supplementation of active charcoal could improve fish performance and feed intake and the optimum level was found to be 8 g/kg,and active charcoal supplementation could enhance the antioxidant activity and thereby reducing heavy metal accumulation in fish body.