Department of Fish Biology and Ecology, Central Laboratory for Aquaculture Research, Agriculture Research Center, Abbassa, Abo-Hammad, Sharqia, 44662, Egypt.
Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt.
Vet Res Commun. 2024 Feb;48(1):69-84. doi: 10.1007/s11259-023-10176-0. Epub 2023 Aug 2.
Yeast, Saccharomyces cerevisiae, has been utilized as a probiotic in aqua-feeds to promote growth and alleviate the stress in aquatic animals. On the other hand, cadmium (Cd) toxicity causes serious retardation of growth and welfare status of aquatic animals. The present study was conducted to evaluate the protective role of dietary yeast in mitigating the waterborne Cd toxicity effects on the growth, haemato-biochemical, stress biomarkers, and histopathological investigations of gilthead seabream (Sparus aurata L.). In a 3 × 3 factorial design, the acclimated fish (20-24 g) were randomly distributed into nine treatments in triplicates where they were fed on 0.0% (control), 0.5%, and 1.0% of yeast along with exposure to 0.0, 1.0, and 2.0 mg Cd/L for 60 days. All growth parameters and mRNA expressions of IGF-1 and GH genes as well as haematological parameters were markedly increased with the increase of dietary yeast levels; meanwhile these variables were significantly retarded with Cd exposure. Contradictory effects on the above-mentioned variables were observed with Cd toxicity. In contrast, blood cortisol, glucose, total cholesterol, and triglyceride, lactate dehydrogenase, alanine transaminase, aspartate transaminase, alkaline phosphatase, in addition to DNA fragments % were noticeably increased with Cd toxicity especially at the treatment of 2.0 mg Cd/L, while decreasing with increasing dietary yeast levels. Compared with the control fish group, Cd concentrations in the gill, liver, and muscle tissues of gilthead seabream were higher in Cd-exposed treatments, especially at the treatment of 2.0 mg Cd/L. Deposition of Cd in fish liver was higher than that in gill tissues but lowest Cd residue was observed in muscle tissues. No significant changes in Cd residues in fish organs were observed in yeast-fed fish with no Cd exposure. The Cd exposure negatively affected histological status of gill, liver, and kidney tissues of S. aurata; while feeding Cd-exposed fish on yeast diets lowered the Cd residues in fish organs and recovered the adverse effects of Cd toxicity. Hence, this study recommends the addition of bakery yeast (1.0%) to fish diets to improve the performance, overall welfare, and histopathological status of gilthead seabream, S. aurata.
酵母，酿酒酵母，已被用作水产饲料中的益生菌，以促进生长和减轻水生动物的应激。另一方面，镉（Cd）毒性会严重减缓水生动物的生长和福利状况。本研究旨在评估日粮酵母在减轻水生 Cd 毒性对金头鲷（Sparus aurata L.）生长、血液生化、应激生物标志物和组织病理学研究的影响中的保护作用。在 3×3 因子设计中，适应环境的鱼（20-24g）被随机分为 9 个处理组，每组 3 个重复，分别投喂 0.0%（对照）、0.5%和 1.0%的酵母，并暴露于 0.0、1.0 和 2.0mg Cd/L 下 60 天。随着日粮酵母水平的增加，所有生长参数和 IGF-1 和 GH 基因的 mRNA 表达以及血液学参数均显著增加；同时，这些变量随着 Cd 的暴露而显著延迟。与 Cd 毒性相比，对上述变量产生了相反的影响。相反，随着 Cd 毒性的增加，血液皮质醇、葡萄糖、总胆固醇和甘油三酯、乳酸脱氢酶、丙氨酸转氨酶、天冬氨酸转氨酶、碱性磷酸酶以及 DNA 片段%均显著增加，尤其是在 2.0mg Cd/L 的处理中，而随着日粮酵母水平的增加而减少。与对照组相比，金头鲷鳃、肝和肌肉组织中的 Cd 浓度在 Cd 暴露处理中较高，尤其是在 2.0mg Cd/L 的处理中。鱼肝中 Cd 的沉积量高于鳃组织，但肌肉组织中 Cd 残留量最低。在没有 Cd 暴露的情况下，酵母喂养的鱼的鱼器官中的 Cd 残留量没有观察到显著变化。Cd 暴露对 S. aurata 的鳃、肝和肾脏组织的组织学状态产生负面影响；而在 Cd 暴露的鱼饲料中添加面包酵母（1.0%）可以降低鱼器官中的 Cd 残留量，并恢复 Cd 毒性的不利影响。因此，本研究建议在鱼饲料中添加面包酵母（1.0%），以提高金头鲷的性能、整体福利和组织病理学状况。
