混合蛋白源替代鱼粉对花鲈(Lateolabrax maculatus)生长性能、血浆生化指标和肝脏健康的影响

为研究混合蛋白源(酶解猪血球蛋白粉、豆粕和玉米蛋白粉)替代鱼粉对花鲈生长性能、血浆生化指标和肝脏健康的影响,配制6组等氮等脂(粗蛋白约为45%、粗脂肪约为8%)饲料,以30%的鱼粉作为对照组(RF0组),在对照组基础上分别用混合蛋白源替代2.5%、5.0%、7.5%、10.0%和12.5%的鱼粉,分别记为RF1、RF2、RF3、RF4组和RF5组,分别投喂6组花鲈[初始均重(11.40±0.15)g],养殖周期56 d。结果显示:①RF1组末均重、特定生长率、增重率、溶菌酶和碱性磷酸酶活性显著高于其他各组(P<0.05),总抗氧化能力、过氧化氢酶和谷胱甘肽过氧化物酶活性显著高于RF0组(P<0.05);②随着混合蛋白源替代鱼粉比例升高,肝体比、脏体比、肥满度、谷草转氨酶、谷丙转氨酶、微量还原型谷胱甘肽、谷胱甘肽过氧化物酶和谷胱甘肽S-转移酶活性呈上升趋势,而高密度脂蛋白胆固醇呈下降趋势;③RF1、RF2和RF3组试验鱼肝脏切片相比于其他各组,脂质空泡明显改善,肝细胞结构清晰。研究表明,混合蛋白源替代2.5%的鱼粉可提高花鲈的生长性能、增强抗氧化能力、改善其免疫状态和肝脏脂质空泡化。

混合植物蛋白源对罗非鱼幼鱼生长、体组成及表观消化率的影响

以混合植物蛋白源（棉粕/菜粕/玉米蛋白粉/蚕豆的质量比为1∶1∶1∶1）分别替代0%、25%、50%、75%、100%鱼粉,配制成5组等氮（粗蛋白为30%）、等能（总能为20 kJ/g）的饲料,探讨混合植物蛋白源替代鱼粉对初始体质量为（7.16±0.81）g的尼罗罗非鱼幼鱼生长、体组成及消化率的影响,试验期为10周。结果表明：混合植物蛋白源替代25%~75%鱼粉时,罗非鱼的质量增量、特定生长率、蛋白质效率和饲料系数与对照组无显著差异,替代100%鱼粉时,罗非鱼的质量增量、特定生长率和蛋白质效率显著低于其他处理组,饲料系数显著高于其他处理组;混合植物蛋白源替代鱼粉对鱼体的肝体比、脏体比无显著影响;随着混合植物蛋白源替代比例的升高,罗非鱼全鱼粗蛋白质、灰分含量显著降低,粗脂肪含量显著升高,但肌肉的营养组成不受影响;除组氨酸含量随替代比例的增加而升高外,混合植物蛋白源替代鱼粉对鱼体肌肉的必需氨基酸、总氨基酸无显著影响,100%替代组的肌肉呈味氨基酸占总氨基酸比例显著低于对照组,而其他处理组与对照组无显著差异;100%替代组的蛋白质和氨基酸消化率显著低于25%、50%、75%替代组和对照组,但各处理组的脂肪消化率差异不显著。本试验条件下,以生长、体组成及消化率为评价指标,罗非鱼饲料中以混合植物蛋白源替代75%鱼粉是可行的。

Palatability of Water-Soluble Extracts of Protein Sources and Replacement of Fishmeal by a Selected Mixture of Protein Sources for Juvenile Turbot(Scophthalmus maximus)

Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. The present study was conducted to investigate the palatability of water-soluble extracts from single protein source(single extract pellets) and the mixture of these extracts with different proportions(blended extract pellets) in juvenile turbot(Scophthalmus maximus). Then according to the palatability of blended extract pellets, an optimal mixture proportion was selected, and a new protein source made from raw protein materials with the selected proportion was formulated to replace fishmeal. Summarily, the palatability of single extract pellets for turbot was descendent from fishmeal to pet-food grade poultry by-product meal, wheat gluten meal, soybean meal, peanut meal, meat and bone meal, and corn gluten meal. Subsequently, according to the palatability of single extract pellets, 52 kinds of blended extract pellets were designed to test their palatability. The results showed that the pellets presented remarkably different palatability, and the optimal one was diet 52(wheat gluten meal: pet-food grade poultry by-product meal: meat and bone meal: corn gluten meal = 1:6:1:2). The highest ingestion ratio(the number of pellets ingested/the number of pellets fed) was 0.73 ± 0.03, which was observed in Diet 52. Then five isonitrogenous(52% crude protein) and isocaloric(20 k J g^(-1) gross energy) diets were formulated by replacing 0(control), 35%, 50%, 65% and 80% of fishmeal with No.52 blending proportion. After a 10-weeks feeding trial, a consistent feed intake was found among all replacement treatments. Replacement level of fishmeal up to 35% did not significantly influence final body weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio of turbot. Therefore, the water-soluble extracts of protein sources play an important role in improving the palatability of non-fishmeal protein sources in aquafeed.