饲喂不同浓度黄曲霉毒素B1饲料对草鱼幼鱼生长和毒素积累的影响

以含不同浓度黄曲霉毒素B₁(AFB₁)(0、10、20、100、1000和5000 μg/kg饲料)的6种等氮等能(32.96%蛋白质, 14.55 kJ/g能量)配合饲料饲喂平均初始体质量为(2.90±0.16) g草鱼(Ctenopharyngodon idellus)幼鱼84d, 探讨AFB₁对草鱼幼鱼生长、肝胰脏和肾脏组织结构以及鱼体肌肉中的毒素积累的影响。实验分为6个实验组, 每组3个平行。结果表明, 在整个实验过程中各实验组幼鱼的行为均未表现出异常, 各组幼鱼的存活率、终末体重、摄食率、特定生长率、饲料效率、肝体比、脏体比均无显著差异。饲料AFB₁水平对草鱼幼鱼血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(AKP)、超氧化物岐化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性均无显著影响。各毒素组和对照组肝胰脏、肾脏组织学观察中未发现病理变化。摄食AFB₁≤1000 μg/kg的草鱼幼鱼肌肉中未检测出AFB₁残留, 仅在5000 μg/kg实验组中检测出肌肉中含有(1.21±0.18) μg/kg的AFB₁, 低于FDA食品安全限定标准。由此可见, 草鱼幼鱼至少可耐受AFB₁含量达5000 μg/kg饲料(实测值: 4979.2 μg/kg饲料) 84d。

EFFECTS OF AFLATOXIN B1 ON GROWTH AND TISSUE ACCUMULATION OF JUVENILE GRASS CARP (CTENOPHARYNGODON IDELLUS)

A 84-day feeding trial was conducted to evaluate the effects of dietary aflatoxin B₁ (AFB₁) on growth, physiological responses, histological changes, and accumulation in juvenile grass carp (Ctenopharyngodon idellus). Triplicate groups of grass carp (2.90±0.16) g] were fed with six semipurified diets formulated with isonitrogenous (crude protein: 32.96%), isocaloric (gross energy: 14.55 kJ/g) containing 0, 10, 20, 100, 1000 and 5000 μg/kg AFB₁. AFB₁ did not significantly impact behavior, the survival rate, final body weight (FBW), feeding rate (FR), specific growth rate (SGR) or feed efficiency (FE). No significant differences were found in hepatosomatic index (HSI) and viscera index (VSI) among all groups. AFB₁ had no significant effect in activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). No significant histological lesions in hepatopancreas and kidney were identified between the control and increasing AFB₁ treatments. No AFB₁ residue was detected in muscles when fish fed with AFB₁ up to 1000 μg/kg, however, tiny dose (1.21±0.18) μg/kg] of AFB₁ were detected in muscles in the group with 5000 μg/kg AFB₁, which was below the safety limitation of FDA. The results indicated that juvenile grass carp is a little susceptible species to AFB₁ exposure up to approximately 5000 μg/kg diet (determined level was 4979.2 μg/kg diet), at least for 84 days.