Abstract The purpose of the study was to investigate the impacts of dietary narrow-leafed lupin Lupinus angustifolius kernel meal (LKM) on growth performance, feed utilization, digestibility, haematology, as well as liver and intestinal health of juvenile cobia Rachycentron canadum. Five isonitrogenous (crude protein around 460.0 g/kg) diets were formulated to replace 0, 200, 400, 600 and 800 g/kg of fishmeal protein with the protein from LKM designated as LKM0, LKM20, LKM40, LKM60 and LKM80, respectively. Triplicate groups of cobia were fed the respective diets for a period of 56 days. At the end of the feeding trial, growth indices expressed as final body weight (FBW) and specific growth rate (SGR) decreased following the linear and quadratic models with increasing levels of LKM. Feed intake, protein retention and energy retention followed the same trend, whereas, feed conversion ratio (FCR) and hepatosomatic index (HSI) followed a reverse trend with FBW and SGR. A significant decrease in the apparent digestibility coefficient of protein, lipid and dry matter was observed in cobia when more than 400 g/kg protein from fishmeal was substituted by LKM protein. Haematological indices such as red blood cell and haemoglobin declined significantly in fish fed with LKM60 and LKM80, while a significant increase was observed in aspartate transaminase and alanine aminotransferase. Histopathological alterations including higher lipid deposition, necrosis and vacuolization were found in the liver of fish fed higher (>600 g/kg) fishmeal protein replacement levels. Similarly, intestinal structure was affected by higher replacement level of fishmeal protein (>600 g/kg) as fold height and goblet cells decreased significantly with increasing levels of LKM. The results indicate that 200 g/kg fishmeal protein can be replaced by protein from LKM and substitution beyond that level adversely affected the growth performance of cobia.

中文翻译：

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在军曹鱼 Rachycentron canadum 的饮食中用羽扇豆羽扇豆仁粉代替鱼粉：对生长性能、营养利用、血液生理反应和肠道健康的影响

摘要 本研究的目的是研究日粮窄叶羽扇豆羽扇豆仁粕 (LKM) 对军曹鱼 Rachycentron canadum 幼鱼生长性能、饲料利用率、消化率、血液学以及肝脏和肠道健康的影响。配制了五种等氮（粗蛋白约 460.0 g/kg）日粮，分别用 LKM 中的蛋白 LKM0、LKM20、LKM40、LKM60 和 LKM80 代替 0、200、400、600 和 800 g/kg 的鱼粉蛋白。三组军曹鱼分别饲喂各自的饮食，持续 56 天。在饲养试验结束时，随着 LKM 水平的增加，以最终体重 (FBW) 和比生长率 (SGR) 表示的生长指数按照线性和二次模型下降。采食量，蛋白质保留和能量保留遵循相同的趋势，而饲料转化率 (FCR) 和肝体指数 (HSI) 与 FBW 和 SGR 遵循相反的趋势。当鱼粉中超过 400 g/kg 的蛋白质被 LKM 蛋白替代时，在军曹鱼中观察到蛋白质、脂质和干物质的表观消化率系数显着降低。用 LKM60 和 LKM80 喂养的鱼的红细胞和血红蛋白等血液学指标显着下降，而天冬氨酸转氨酶和丙氨酸转氨酶则显着增加。在饲喂较高（>600 g/kg）鱼粉蛋白替代水平的鱼的肝脏中发现了组织病理学改变，包括较高的脂质沉积、坏死和空泡化。相似地，肠道结构受到鱼粉蛋白替代水平较高（>600 g/kg）的影响，因为随着 LKM 水平的增加，折叠高度和杯状细胞显着降低。结果表明，200 g/kg 鱼粉蛋白可以被 LKM 蛋白替代，超过该水平的替代对军曹鱼的生长性能产生不利影响。