School of Aquatic Sciences and Fisheries Technology (SoAF)

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https://repository.udsm.ac.tz/handle/20.500.11810/5553
School of Aquatic Sciences and Fisheries Technology, formerly department of Aquatic Sciences and Fisheries in the College of Agriculture and Fisheries (CoAF)

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Browsing School of Aquatic Sciences and Fisheries Technology (SoAF) by Subject "Aquaculture"

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    Antibiotics Use in African Aquaculture: Their Potential Risks on Fish and Human Health. In: Abia A. and Lanza G. (Eds) Current Microbiological Research in Africa. Springer, Cham, pp. 203-221.
    (Springer, 2020-02) Samwel Mchele Limbu
    Antibiotics are used abusively in humans and agriculture, including aquaculture, making them omnipresent in the environment, posing health risks to aquatic animals and humans. However, how antibiotics affect the anatomy and physiology of fish, including the presence of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in fish in Africa are currently poorly understood. This chapter synthesized the available literature on the potential risks of antibiotics on cultured fish and human health from Africa. The limited available studies indicate that few antibiotics improve fish growth but do not affect their survival rate. Antibiotics application on fish cause body malformation and damage, which induce hepatotoxicity, nephrotoxicity, leukocytosis, hematopoiesis, and lymphocytosis, suggesting sustained toxic effects. Antibiotics use in fish and other foods like shrimps and vegetables together with antibiotics residues in the aquatic environment have led to an increase in the prevalence of ARB and ARGs, posing a human health risk in various African countries. Limited studies indicate higher residues of antibiotics in cultured fish, which exceed the maximum limits set by the Codex Alimentarius Commission and the World Health Organization. Thus, policies and mechanisms for limiting the use of antibiotics in food animals to protect human health in Africa are urgently needed.
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    Dietary L-carnitine supplementation recovers the increased pH and hardness in fillets caused by high-fat diet in Nile tilapia (Oreochromis niloticus)
    (Elsevier, 2022-07-15) Zhi-Yong Zhang; Samwel Mchele Limbu; Si-Han Zhao; Li-Qiao Chen; Yuan Luo; Mei-Ling Zhang; Fang Qiao; Zhen-Yu Du
    The wide use of high-fat diet (HFD) causes negative effects on flesh quality in farmed fish. l-carnitine, a lipid-lowering additive, enhances mitochondrial fatty acid β-oxidation. However its roles in alleviating the effects of HFD on flesh quality in fish are unknown. We fed Nile tilapia with medium-fat diet (MFD, 6% dietary lipid), high-fat diet (HFD, 12% dietary lipid) and HFCD supplemented with l-carnitine (HFCD + 400 mg/kg l-carnitine) for 10 weeks. The HFD-fed fish had higher fat deposition, pH value, myofiber density and flesh hardness than those fed on MFD. However, feeding the fish with the HFCD improved lipid catabolism, which increased significantly lactic acid content and myofiber diameter in muscle, thus reduced pH and hardness values. HFCD also reduced endoplasmic reticulum stress and myofiber apoptosis caused by HFD in the fish. Our study suggests that dietary l-carnitine supplementation alleviates the negative effects of HFD on flesh quality of farmed fish.