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D. J. Johnston K. A. Calvert B. J. Crear C. G. Carter 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):667-682
The availability of formulated diets is considered economically imperative if rock lobster aquaculture, based on the collection and ongrowing of puerulus, is to progress. Central to the development of diets is an understanding of the nutritional requirements of the species. This study determined the effect of different dietary carbohydrate/lipid ratios (17:1, 5:1, 2:1, 0.8:1) on the growth and nutritional condition of juvenile southern rock lobsters, Jasus edwardsii, by measuring standard growth parameters, proximate composition of the whole body and digestive gland, and from a histological investigation of the digestive gland. Four replicate groups of eight lobsters (initial weight 5.08±0.98 g (mean±S.D.)) per diet treatment were held in 50 l tanks, in a recirculating system at 18 °C for 84 days. Maximum growth and the highest levels of lipid and dry matter in digestive glands and whole bodies was found in lobsters fed a diet containing 27% carbohydrate and 13.5% lipid (2:1 ratio) suggesting that of the four experimental diets, this diet provided the best balance of lipid and carbohydrate. Digestive gland histology supported this conclusion and lobsters fed low carbohydrate, high lipid diets were in the best nutritional condition, with high lipid accumulation, and structurally sound epithelial cells. Digestive gland epithelial cells of lobsters fed the high carbohydrate, low lipid diets were compressed, of inconsistent shape and size, with low lipid accumulation. Histology is therefore seen as a feasible method, in addition to growth and proximate composition data, to further examine the effect of diets in nutritional studies of crustaceans. 相似文献
53.
XIA Jinhui 《长江蔬菜》2008,(20)
研究马铃薯会-2的干物质积累及氮、磷、钾养分的吸收、积累和分配特征,结果表明,会-2叶片对氮、磷、钾的吸收速率与干物质积累速率的变化同步,呈双峰曲线变化,分别在现蕾期和终花期间出现峰值;块茎干物质积累及养分吸收速率呈单峰曲线,块茎干物质主要在盛花期至茎叶枯萎期形成,该期也是块茎养分积累的主要时期;终花期以前,干物质及养分主要分配在地上部分,终花期以后,主要分配在块茎中;会-2对氮(N)、磷(P2O5)、钾(K2O)的吸收比例为1∶0.140∶1.919;生产500kg块茎,需吸收N2.756kg,P2O50.310kg,K2O4.256kg。 相似文献
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Like marine fish freshwater fish are an important source of essential fatty acids for human nutrition. However, the fatty
acid composition of pond fish can vary considerably and strongly depends on that of the ingested food. Investigations on the
fatty acid composition of common carp (Cyprinus carpio) and tench (Tinca tinca) have shown that different methods of rearing and feeding cause substantial variations in the proportions of the n-6 and
n-3 polyunsaturated fatty acids of these fish species. Carp reared on the basis of natural food in ponds exhibit high contents
of n-6 as well as n-3 fatty acids in their muscle triacylglycerols. On the other hand carp fed supplementary wheat in ponds
resulted in somewhat lower levels of these essential fatty acids. High amounts of n-3 fatty acids can be found in carp fed
high-energy diets containing high levels of fish oil. Analogous results were obtained in experiments with tench reared under
different nutritional conditions. While rearing on the basis of only natural food in ponds as well as feeding supplementary
wheat yielded in similar levels of n-3 and n-6 polyunsaturated fatty acids, higher contents of n-3 fatty acids were recorded
in tench fed pellets. High levels of n-3 polyunsaturated fatty acids in foodstuffs have positive effects on human health.
Experiments with different cultured fish species proved that the fatty acid composition of the edible parts can be influenced
by the diet. Therefore, a finishing diet with a suitable fatty acid profile can be used to improve the nutritional quality
of fish products of farmed origin. 相似文献
56.
为进一步认识和评价黄条(Seriola aureovittata)的营养与食用价值,本研究测定了其肌肉中的水分、蛋白质、粗脂肪、灰分、氨基酸、脂肪酸和矿物质等成分,并对其养殖及野生个体的肌肉营养成分组成进行了比较分析.结果显示,黄条肌肉中蛋白质含量较高,必需氨基酸和鲜味氨基酸含量丰富,完全符合FAO/WHO推荐的理想蛋白质标准,是一种优质蛋白供给源.根据AAS和CS分值,黄条肌肉的第一限制氨基酸为蛋氨酸,第二限制氨基酸为缬氨酸.黄条肌肉的脂肪含量高于三文鱼(Salmo salar)、金枪鱼(Thunnus thynnus)、石斑鱼(Epinephelus sp.)等,且肌肉中含有丰富的不饱和脂肪酸,不饱和脂肪酸与饱和脂肪酸比值较高,特别是EPA+DHA的含量高,具有较优的口感鲜度和较高的营养价值.另外,黄条肌肉中含有多种机体新陈代谢所需的矿物质,经常食用可促进人体新陈代谢水平.比较发现,养殖黄条较野生黄条具有相对较高的脂肪含量和较低的水分含量,比能值(EP)分别为13.44 kJ/g和8.68 kJ/g,其他营养成分无显著差异,表明养殖与野生黄条肌肉营养价值相似.综上所述,黄条肌肉蛋白质和脂肪质量较高,口感鲜美,营养成分丰富,是一种值得大力开发养殖的海产经济鱼类. 相似文献
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南极磷虾营养评价与安全性研究 总被引:10,自引:0,他引:10
对天然生长的南极磷虾肌肉中营养成分与营养品质进行了较全面系统的分析,并结合安全性进行了初步研究。结果表明,南极磷虾肌肉(干样)中粗蛋白含量64·44%,粗脂肪含量5·14%,粗灰分含量10·90%,无氮浸出物含量19·52%;18种氨基酸总量为57·16%,其中8种人体必需氨基酸含量为25·88%,占氨基酸总量的45·25%;必需氨基酸指数(EAAI)为54·94,其构成比例符合FAD/WHO的标准;4种鲜味氨基酸含量为23·06%,占氨基酸总量的35·98%;矿物质含量丰富;铅、汞、镉、砷几种重金属含量平均值均低于相关食品卫生标准限量。综合分析认为,南极磷虾是一种食用安全、营养价值较高的虾类,具有良好的开发利用前景。 相似文献
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