杜仲叶提取物对异育银鲫生长、血清非特异性免疫和肌肉品质的影响

    进行两个试验考察饲料中添加杜仲叶提取物对异育银鲫生长、血清非特异性免疫和肌肉品质的影响试验一:采用平均体重为(240±20)g的异育银鲫鱼种,在基础饲料中分别添加00%(对照组)、01%、015%和02%杜仲叶提取物,饲养8周后,各组异育银鲫增重率分别为1249%、1279%、1410%、1232%,其中添加015%杜仲叶提取物较对照组显著提高鱼体增重率,降低饲料系数(P<005);对血清非特异性免疫指标的测定表明:添加01%、015%、02%杜仲叶提取物可在不同程度上提高血清超氧化物歧化酶(superoxide dismulasc,SOD)、溶茵酶(lysozyme,LSZ)和碱性磷酸酶活性(alkaline phosphatase,AKP),其中添加015%杜仲叶提取物对血清非特异性免疫指标的影响最显著;在肌肉品质方面,添加015%杜仲叶提取物可提高肌肉粗蛋白含量和肌肉耐折力(P<005),降低肌纤维直径和肌肉失水率(P<005)试验二:在基础饲料(含05%Cr2O3)中分别添加00%(对照组)、01%、015%和02%杜仲叶提取物,饲养平均体重为(553±35)g的异育银鲫,测定饲料营养物质消化率及肠道蛋白酶活性结果表明:添加015%杜仲叶提取物可显著提高异育银鲫粗蛋白消化率、干物质消化率和肠道蛋白酶活性(P<005)上述结果表明,饲料中添加015%杜仲叶提取物可提高异育银鲫对营养物质的消化率,促进生长,提高血清非特异性免疫力,改善肌肉品质     

不同倍性鲫鲤MeCP2基因分子克隆及时空表达分析

为了探寻不同倍性鱼生殖育性的表观遗传调控规律,实验基于不同倍性鲫鲤精巢的转录本信息库设计引物克隆了不同倍性鲫鲤的MeCP2基因。序列比对结果发现,在远缘杂交的过程中基因组发生了遗传重组和变异。基于序列公共部分设计引物,通过半定量PCR和实时定量PCR的方法分析了MeCP2基因在不同倍性鱼发育过程中的时空表达特征。结果还发现,MeCP2基因在所有组织中都有表达,但在脑组织中的表达量最高;纵向对比性腺的发育过程,MeCP2基因的表达量会随着性腺发育成熟而下降;横向对比不同倍性鱼的性腺发育,MeCP2基因在三倍体鱼卵巢中的表达量明显高于二倍体和四倍体鱼,但在精巢中的表达量随鱼的倍性增加而增加。研究表明,MeCP2基因的表达与不同倍性鱼的卵巢发育密切相关,这为研究鱼类生殖不育的分子机理及其在水产育种上的应用奠定了坚实的基础。     

博斯腾湖草鱼生长特征的研究

根据2014年8月采集的33尾标本对博斯腾湖草鱼(Ctenopharyngodon idellus)的生长特征进行研究。以鳞片为年龄和生长退算材料,研究结果显示:博斯腾湖草鱼体重与体长表现为异速生长,关系式为W=0.0444SL~(2.8322)。用退算体长拟合的von Bertalanffy生长参数为:SL_8=103.7664 cm,k=0.1385/y,t_0=-0.0542 y。体重生长参数为:W_8=22.7674 kg,k=0.1385/y,t_0=0.0027 y。生长特征指数为3.16;生长拐点年龄为7.5龄,拐点时体长和体重分别为67.3 cm和6.6 kg。与1979年和2000年种群相比,受饵料供给不足的制约,博斯腾湖草鱼生长速度明显下降。草鱼增殖管理措施的制定应以恢复沉水植物资源为目标,具体措施包括:减少草鱼的投放量,草鱼最小捕捞规格降至3 kg,提高草鱼的捕捞强度和捕捞量。     

黑龙江水产研究所鲤育种概要

本文主要概述黑龙江水产研究所鲤Cyprinus carpio育种工作历史,介绍杂交选育亲本的来源与生物学特点以及育成品种的选育方法、技术路线和优良性状。通过引入国内外名优鲤,采用常规杂交选育、多性状遗传分析和分子辅助育种等方法,本土化培育出多个适合北方寒冷地区养殖的鲤新品种。采用的亲本包括黑龙江鲤C.C.amurensis、荷包红鲤C.C.var.wuyuanensis、散鳞镜鲤C.C.var.specularis amurensis、德国镜鲤C.C.var.S.germanensis和大头鲤C.pellegrini。育成品种包括荷包红鲤抗寒品系、松浦鲤C.C.'Songpu'、松荷鲤C.C.'Songhe、松浦红镜鲤C.C.'Songpu red mirror'、德国镜鲤选育系F_4、松浦镜鲤C.C.var.S.'Songpu'和易捕鲤。这些品种都具有抗寒、抗逆、易捕和快速生长等特性,适合北方以及全国各地养殖,其中松荷鲤、松浦镜鲤占有很大的市场份额,为我国的渔业发展做出了巨大的贡献。     

Dietary methionine requirement of the pre‐adult gibel carp (Carassius auratus gibeilo) at a constant dietary cystine level

A 62‐day growth trial was conducted to determine the dietary Met requirement of the pre‐adult gibel carp (Carassius auratus gibeilo) (initial weight of 51.0 ± 0.02 g). Six isonitrogenous and isoenergetic diets using fish meal, blood meal and pea protein concentrate as protein sources supplemented with crystalline amino acids were formulated to contain graded levels of dietary Met (4.44, 6.56, 8.55, 10.90, 12.79 and 15.05 g kg^?1, respectively) at a constant dietary cystine level of 3.99 g kg^?1. The results showed that weight gain rate and protein productive value significantly increased with the dietary Met levels from 4.44 to 8.55 g kg^?1, then reached plateau at 10.90 g kg^?1. Plasma HDL‐C and TC were increased with dietary Met levels. Fish supplied with 4.44–8.55 g kg^?1 Met showed lower plasma AST level than that of other groups. Plasma TG, LDL‐C and ALT levels were stable for all treatments. The activity of intestinal γ‐GT was increased with dietary Met levels. The optimal requirement of Met for pre‐adult gibel carp (>50 g) was a range from 7.86 g kg^?1 to 9.84 g kg^?1 dry diet or 16.9 g kg^?1 to 23.0 g kg^?1 of dietary protein with the presence of 3.99 g kg^?1 Cys for the satisfied lipid metabolism and maximum growth, respectively.     

Effects of dietary mono‐ and multiprobiotic strains on growth performance,gut bacteria and body composition of Javanese carp (Puntius gonionotus,Bleeker 1850)

This study investigated the effects of dietary mono‐ and multiprobiotic strains of Enterococcus faecalis, Lactobacillus fermentum and Leuconostoc mesenteroides on growth performance, intestinal bacteria and body composition of Javanese carp (Puntius gonionotus). Moreover, the effect of storage temperature on lactic acid bacteria (LAB) viability in the feed was studied. Compared to the control group, significant (P < 0.05) effect on weight gain, feed conversion ratio, specific growth rate and protein efficiency ratio of probiotic fed Javanese carp was observed. Inclusion of individual LAB strains in the diet resulted in significantly improved growth performances of Javanese carps compared to fish fed a diet supplemented LAB mixture. The inclusion level of E. faecalis at 10⁷ colony‐forming unit (cfu) g⁻¹ in the diet revealed higher growth performance compared to other treatments. The population levels of LAB in the fish intestine were significantly increased while the levels of Gram‐negative bacteria were significantly decreased compared to the control. No significant variations were observed in the chemical composition of the carcass by probiotics. The viability of LAB in feed was higher when stored at 4 °C compared to 25 °C. It is suggested that E. faecalis has a greater potential for use in improving Javanese carp culture outcomes.     

Effects of feeding frequency and dietary protein levels on juvenile allogynogenetic gibel carp (Carassius auratus gibelio) var. CAS III: growth,feed utilization and serum free essential amino acids dynamics

A 8 week growth trial of three feeding frequencies (2, 4 and 6 meals day^?1) and three dietary protein levels (30%, 34% and 38%) was conducted to investigate the influence of feeding frequency and dietary protein level on growth, feed utilization, serum free essential amino acids (EAA) dynamics and nitrogen (N), phosphorus (P), carbon (C) retention in juvenile allogynogenetic gibel carp (Carassius auratus gibelio) ‘CAS III’. The results showed that feeding frequency and dietary protein level increased feed intake (FI), specific growth rate (SGR) and feed efficiency (FE). SGR increased significantly with the increase in feeding frequency and dietary protein level. But, the increase in dietary protein level from 30% to 38% in group 6 meals day^?1 did not result in better growth. Compared with the group of 4 meals day^?1 × 38%, the fish fed the diet containing 30% crude protein at 6 meals day^?1 obtained similar SGR but showed lower FIp (protein intake). Compared with 2 meals day^?1, NREs (nitrogen retention efficiency) of 4 and 6 meals day^?1 were relatively higher. PRE (phosphorus retention efficiency) and CRE (carbon retention efficiency) increased significantly with feeding frequency while TNW (total nitrogen waste output), TPW (total phosphorus waste output) and TCW (total carbon waste output) decreased significantly. Feeding frequency and dietary protein level increased trypsin activity. Serum free EAA concentrations varied more synchronously at 6 meals day^?1 than 2 meals day^?1. It could be concluded that increasing feeding frequency could improve growth by increasing feed intake and feed efficiency for juvenile gibel carp. The increase in feeding frequency showed protein‐sparing effect.     

Effects of total replacement of fish oil by pork lard or rapeseed oil and recovery by a fish oil finishing diet on growth,health and fish quality of gibel carp (Carassius auratus gibelio)

An 84‐day growth trial was designed to investigate effects of dietary replacements fish oil with pork lard (PL) or rapeseed oil (RO) on growth and quality of gibel carp (Carassius auratus gibelio var. CAS III) (initial body weight: 158.2 ± 0.2 g), and responses of the fish refed fish oil (FO) diet. Three isonitrogenous (crude protein: 30%) and isolipid (crude lipid: 10%) diets were formulated containing 7.73% FO, PL or RO. Five experimental treatments including FO group (FO), PL group (PL), RO group (RO), group fed PL for 42 days and refed FO for 42 days (PL+rFO), RO and refed FO group (RO+rFO) was tested. At the end of first 42 days, the fish fed PL and RO had higher mortality than that of the control (P > 0.05). At the end of whole experiment, fish fed PL and RO showed higher plasma cortisol than FO fish (P < 0.05). RO+rFO fish showed higher lysozyme activity than RO fish (P < 0.05). Fish growth and feed utilization, composition of whole body and muscle, free amino acids, texture, off‐flavour substances or sensory attributes were not affected by dietary treatments (P > 0.05). PL and RO diet decreased muscle EPA, DHA and n‐3/n‐6 ratio (P < 0.05), while FO‐refeeding had recovery effect. It can be concluded that the replacement of FO by PL and RO does not affect the growth, feed utilization or fish tasting quality in gibel carp. Fish muscle fatty acids modified by dietary PL and RO can be recovered by refeeding with FO diet.     

异育银鲫溶血性腹水病病原的研究

本文对上海市郊县和江苏省吴江县的异育银鲫溶血性腹水病,进行了病原分离和人工感染试验。对致病菌株进行了细菌学鉴定,其分别为运动型气单胞菌的苏伯利气单胞菌(Aeromonas sobria)和嗜水气单胞菌(A.hydrophila)。通过对人工感染病鱼血清内毒素(En-dotoxin)的测定,并用菌体破碎液注射健康鱼体试验,初步认为病原产生和释放的内毒素类物质,是使鱼类致病和死亡的主要原因之一。