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In the present study, utilization and nutrient digestibility of mango seeds and palm kernel meal by juvenile Labeo senegalensis (Antheriniformes: Cyprinidae) were investigated under laboratory conditions. The two ingredients were incorporated at separate levels of 0%, 10%, 20% and 30%. The feeding period lasted for 12 weeks. In general, best growth and feeding performance was obtained with the control diet (0% of mango seeds and palm kernel meal), but results were not significantly different (P > 0.05) from those obtained with the 10% palm kernel meal inclusion level. Weight gain of fish fed all diets was above 120%. With the exception of the 20% and 30% mango seed inclusion level, the specific growth rate (SGR) of the fish was above 1% day−1. The protein productive values were not significantly (P > 0.05) different between the experimental diets. Protein and carbohydrate digestibility was above 86% and 45%, respectively, in all diets. Proximate composition of fish carcass, hepato-somatic index, liver glycogen and plasma glucose after the feeding trials revealed no evidence of nutritional pathology. It was concluded, that at appropriate levels, palm kernel meal and, to a lesser extent, mango seeds can be incorporated into diets of juvenile L. senegalensis without significant depression of growth and health of the fish.  相似文献   
2.
Abstract. The acute toxicity of water extracts of the barks of two molluscicidal and piscicidal plants, Balanites aegyptiaca and Kigelia africana , to the Nile tilapia, Oreochromis niloticus (L.), was investigated using static bioassays and continuous aeration over a period of 96h. The 96-h LC50, opercular ventilation rates and tail beat frequency were determined. Extract of B. aegyptiaca was observed to be more toxic than that of K. africana . Opercular ventilation and tail fin beat increased sharply with exposure to both extracts and then declined as the fish became fatigued. Death is believed to be due to both fatigue and direct toxic effects of the plant extracts on the fish tissues.  相似文献   
3.
This study evaluated the effects of dietary Aloe vera polysaccharides on growth performance, feed utilization, hemato-biochemical parameters, and resistance against low water pH in African catfish (Clarias gariepinus) fingerlings. Fish were divided into five triplicate groups before being fed feeds supplemented with 0% (control), 0.5%, 1.0%, 2.0%, and 4.0% A. vera/kg diet for 8 weeks. Fish fed 1.0% A. vera/kg diet had significantly increased (P < 0.05) growth parameters (i.e., final weight, weight gain, absolute growth rate, and specific growth rate) compared to unsupplemented ones. Among dietary groups, significantly lower feed conversion ratio was presented in fish fed 1.0% followed by those fed 0.5, 2.0%, and 4.0% A. vera/kg diet (P < 0.05). The protein efficiency ratio was significantly higher (P < 0.05) in fish fed 1.0% A. vera/kg diet compared to unsupplemented fish and those fed 4.0% A. vera/kg diet, respectively. Dietary A. vera polysaccharide crude extracts requirement suitable for growth and feed utilization was estimated to be between 1.76 and 1.79% A. vera/kg diet. Overall, A. vera extracts had improved hemato-biochemical indices when compared to unsupplemented fish, and decreased some of the indices, especially at high dietary inclusion level (4%/kg diet). Furthermore, A. vera-supplemented fish had higher survival probability throughout the low water pH challenge period, except those fed 4% A. vera/kg diet and control diet.  相似文献   
4.
The acute toxicity of alkylbenzene sulphonate (ABS) detergent to the toothed carp, Aphyosemion gairdneri (L.), was investigated using static bioassays and continuous aeration over a period of 96 h. The 96-h LC50, opercular ventilation rates per minute and behaviourial responses were evaluated. The 96-h LC was determined to be 25.11 ± 8.4 mg l?1. The toxicant led to an initial increase in the opercular ventilation, which then decreased below the initial values by the 96th hour of exposure. Prior to death, erratic swimming, lost of balance and respiratory distress were observed. Skin lesions and haemorrhaging of the gill filaments were observed on dead fish.  相似文献   
5.
Abstract.— This study examined the long-term effect of a common aquaculture antibiotic, oxytetracycline, on several blood parameters of the Nile tilapia Oreochromis niloticus under laboratory conditions. The fish were fed daily on isocaloric (24.56 ± 0.96 J/mg gross energy) and isonitrogenous (38.89 ± 0.08% crude protein) diets incorporated with varying concentrations of the drug (5.00, 2.50, 1.25 and 0.63%) for 8 wk. A control diet with no oxytetracycline was fed to another group of fish. Significant reductions in leukocyte, erythrocyte, thrombocyte, hematocrit, and hemoglobin values were observed, the reductions being directly proportional to the concentrations of the drug in the diet, indicating an anemic response. Though the use of oxytetracycline in aquaculture can be beneficial, the results from this investigation suggest that the drug may have some level of interference with the blood chemistry of the fish at therapeutic dosage.  相似文献   
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