通过两个试验研究了壳聚糖对饲料中镉致罗非鱼急性毒性的影响。试验1将360尾罗非鱼随机分为两个处理(对照组和试验组),每个处理3个重复,比较壳聚糖添加后饲料镉致罗非鱼96 h半致死剂量的变化情况。对照组一次性投喂镉水平分别为0.00%、0...通过两个试验研究了壳聚糖对饲料中镉致罗非鱼急性毒性的影响。试验1将360尾罗非鱼随机分为两个处理(对照组和试验组),每个处理3个重复,比较壳聚糖添加后饲料镉致罗非鱼96 h半致死剂量的变化情况。对照组一次性投喂镉水平分别为0.00%、0.10%、0.25%、0.50%、1.00%和2.00%的6种对照饲料;试验组饲料镉含量与对照组相同,并加入10%壳聚糖,同法进行饲料镉对罗非鱼的急性毒性试验。试验2将160尾罗非鱼随机分为两个处理,每个处理4个重复,分别投喂镉含量为0.50%的对照组和试验组饲料,研究饲料中添加壳聚糖对镉致罗非鱼半致死时间的影响。试验结果为:两个试验中试验组鱼的死亡率均低于对照组;对照组96 h半致死剂量(LD50)和半致死时间(LT50)分别为(49.67±6.11)mg/kg.BW和(47.76±3.03)h,试验组96 h LD50和LT50分别为(86.05±6.11)mg/kg.BW和(65.20±6.09)h,试验组96 h LD50和LT50与对照组相比差异极显著(P<0.01),表明壳聚糖能够缓解饲料中镉对罗非鱼的急性毒性。展开更多
根据Cd2+对邻菲啰啉和亮黄阴离子所产生的共振光散射具有显著增强作用,实验建立了共振光散射法测定饲料中镉含量的新方法。在pH 8.0氨-氯化铵缓冲溶液中,Cd2+与邻菲啰啉和亮黄阴离子发生离子缔合反应,使共振光散射显著增强。经优化最佳...根据Cd2+对邻菲啰啉和亮黄阴离子所产生的共振光散射具有显著增强作用,实验建立了共振光散射法测定饲料中镉含量的新方法。在pH 8.0氨-氯化铵缓冲溶液中,Cd2+与邻菲啰啉和亮黄阴离子发生离子缔合反应,使共振光散射显著增强。经优化最佳实验条件为:10 mL比色管中加入0.8 mL pH 8.0氨-氯化铵缓冲溶液、2.0 mL 1.0×10-4mol/L邻菲啰啉溶液和1.5 mL 2.0×10-5mol/L亮黄溶液,室温反应8 min后测定。结果表明,最大共振光散射峰位于625 nm,共振光散射增强程度与Cd2+浓度在0～10μg/L线性关系良好,方法检出限为0.086μg/L(n=11)。采用巯基棉分离技术,测定饲料中镉含量,结果与原子吸收法一致,相对标准偏差为2.4%～3.2%(n=5),样品加标回收率为97.3%～98.9%。展开更多
Study was conducted to assess the possible transfer of heavy metals from livestock feeds to animal products. In experiment-l, samples （n = 503） collected from conventional farms in Central Greece were analysed for h...Study was conducted to assess the possible transfer of heavy metals from livestock feeds to animal products. In experiment-l, samples （n = 503） collected from conventional farms in Central Greece were analysed for heavy metal Copper （Cu）, Zinc （Zn）, Cadmium （Cd）, Lead （Pb）, Nickel （Ni） and Chromium （Cr） contents in muscle tissues, livers, kidneys, excremental and basic mixtures in livestock such as cows and sheep. Results showed that transfer of heavy metal contaminants from feed to animal products fluctuated below the permissible risk levels. In experiment 2, samples （n = 440） of feedstuffs used in different feeding regimens and seasons at different livestock farms [sheep （n = 140）, dairy cows （n = 180）, pigs （n = 120）] were collected. Results showed that relatively high concentration of Cu in the excrements of pigs （155 ＋ 9.13） and Zn in the excrements of sheep （144.56 ＋ 5.78） are explained by the use of Cu in the diet of developing piglets and sheep. Ovine showed higher concentration ofNi, Cr, and Pb in their excrements, while, the concentration of heavy metals in forages was under the allowed range to the EU legislation.展开更多
文摘通过两个试验研究了壳聚糖对饲料中镉致罗非鱼急性毒性的影响。试验1将360尾罗非鱼随机分为两个处理(对照组和试验组),每个处理3个重复,比较壳聚糖添加后饲料镉致罗非鱼96 h半致死剂量的变化情况。对照组一次性投喂镉水平分别为0.00%、0.10%、0.25%、0.50%、1.00%和2.00%的6种对照饲料;试验组饲料镉含量与对照组相同,并加入10%壳聚糖,同法进行饲料镉对罗非鱼的急性毒性试验。试验2将160尾罗非鱼随机分为两个处理,每个处理4个重复,分别投喂镉含量为0.50%的对照组和试验组饲料,研究饲料中添加壳聚糖对镉致罗非鱼半致死时间的影响。试验结果为:两个试验中试验组鱼的死亡率均低于对照组;对照组96 h半致死剂量(LD50)和半致死时间(LT50)分别为(49.67±6.11)mg/kg.BW和(47.76±3.03)h,试验组96 h LD50和LT50分别为(86.05±6.11)mg/kg.BW和(65.20±6.09)h,试验组96 h LD50和LT50与对照组相比差异极显著(P<0.01),表明壳聚糖能够缓解饲料中镉对罗非鱼的急性毒性。
文摘根据Cd2+对邻菲啰啉和亮黄阴离子所产生的共振光散射具有显著增强作用,实验建立了共振光散射法测定饲料中镉含量的新方法。在pH 8.0氨-氯化铵缓冲溶液中,Cd2+与邻菲啰啉和亮黄阴离子发生离子缔合反应,使共振光散射显著增强。经优化最佳实验条件为:10 mL比色管中加入0.8 mL pH 8.0氨-氯化铵缓冲溶液、2.0 mL 1.0×10-4mol/L邻菲啰啉溶液和1.5 mL 2.0×10-5mol/L亮黄溶液,室温反应8 min后测定。结果表明,最大共振光散射峰位于625 nm,共振光散射增强程度与Cd2+浓度在0～10μg/L线性关系良好,方法检出限为0.086μg/L(n=11)。采用巯基棉分离技术,测定饲料中镉含量,结果与原子吸收法一致,相对标准偏差为2.4%～3.2%(n=5),样品加标回收率为97.3%～98.9%。
文摘Study was conducted to assess the possible transfer of heavy metals from livestock feeds to animal products. In experiment-l, samples （n = 503） collected from conventional farms in Central Greece were analysed for heavy metal Copper （Cu）, Zinc （Zn）, Cadmium （Cd）, Lead （Pb）, Nickel （Ni） and Chromium （Cr） contents in muscle tissues, livers, kidneys, excremental and basic mixtures in livestock such as cows and sheep. Results showed that transfer of heavy metal contaminants from feed to animal products fluctuated below the permissible risk levels. In experiment 2, samples （n = 440） of feedstuffs used in different feeding regimens and seasons at different livestock farms [sheep （n = 140）, dairy cows （n = 180）, pigs （n = 120）] were collected. Results showed that relatively high concentration of Cu in the excrements of pigs （155 ＋ 9.13） and Zn in the excrements of sheep （144.56 ＋ 5.78） are explained by the use of Cu in the diet of developing piglets and sheep. Ovine showed higher concentration ofNi, Cr, and Pb in their excrements, while, the concentration of heavy metals in forages was under the allowed range to the EU legislation.
