饲料中添加不同脂肪源、VC和VE对大菱鲆生长和非特异性免疫力的影响

研究了不同脂肪源、VC和VE以及上述3种复合营养性添加剂对大菱鲆非特异性免疫力、生长和存活率的影响。结果表明,以鳀鱼鱼油为脂肪源,添加高剂量的VE能提高大菱鲆血清补体活性,并且提高大菱鲆的溶菌酶活性,但不影响大菱鲆血液的中性粒细胞吞噬率及白细胞总数;饲料中VC含量增加到250mg/kg,大菱鲆血液中的白细胞总数明显增加,而进一步提高饲料中的VC含量时,其白细胞总数没有显著变化;血清溶菌酶活性在VC含量为250mg/kg时最高。饲料中VC含量对白细胞的吞噬活性没有影响。在75d的养殖时间内,摄食复合营养性免疫增强剂的大菱鲆,其体重增重率(平均为95·3%)和成活率(99·4%)均明显高于未摄食营养型免疫增强剂的对照组体重增重率(68·0%)和成活率(93·7%)。     

三种免疫添加剂对草鱼非特异性免疫功能的影响

在饲料中添加不同剂量的Vc、酵母多糖和壳聚糖,连续投喂42d,并在试验的第14、28、35和42天取样检测,研究其对草鱼血清溶菌酶活性、血清超氧化物歧化酶活性（SOD）活性、血清碱性磷酸酶（AKP）活性、补体C3、含量丙二醛（MDA）含量和血液白细胞吞噬活性共6种指标的影响。结果显示：实验组与对照组相比,饲料中添加Vc可以提高血清溶菌酶活性、SOD活性、AKP活性、补体C3含量和血液白细胞吞噬活性高,并降低MDA含量。添加酵母多糖可以提高血清溶菌酶活性、AKP活性、补体C3含量和血液白细胞吞噬活性,并降低MDA含量,但不能提高SOD活性。添加壳聚糖可以提高血清溶菌酶活性、SOD活性、AKP活性、补体C3含量和血液白细胞吞噬活性,但不能降低MDA含量。饲料中添加Vc、酵母多糖和壳聚糖均对草鱼的非特异性免疫功能具有一定的促进作用。     

维生素E及脂肪源对大菱鲆非特异性免疫的影响

在大菱鲆饲料中分别添加鲤鱼鱼油及花生油作脂肪源,每种脂肪中添加两个水平的维生素E（8mg／kg和300mg／kg维生素E醋酸酯）,饲养大菱鲆84d,探讨其对大菱鲆非特异性免疫的影响。结果发现,（1）以鲤鱼鱼油为脂肪源的添加高剂量的维生素E能提高大菱鲆血清补体活性,而以花生油为脂肪源的饲料添加高剂量的维生素E不影响大菱鲆血清补体活性;（2）以鲤鱼鱼油和花生油为脂肪源的饲料添加高剂量的维生素E不影响大菱鲆中性粒细胞的吞噬率及白细胞总数;（3）以鲤鱼鱼油为脂肪源的饲料添加高剂量的维生素E能提高大菱鲆的溶茵酶活性,但随着时间推移其影响减弱;（4）饲喂n-3HUFA含量高的饲料,对大菱鲆腹水病的抵抗能力高于n-3HUFA含量低的饲料。     

饲料维生素E含量对美国红鱼生长和非特异性免疫的影响

采用单因子实验设计方法，进行了饲料中添加维生素E对美国红鱼生长（存活率、特定生长率和饲料效率）和非特异性免疫相关指标（血清中溶菌酶活性、血清总补体活性和超氧化物岐化酶（SOD）活性）影响的研究，设计了5个不同维生素E水平（0．1、25．3、51．0、102．8和203．2mg／kg）的等氮等能饲料，对美国红鱼进行为期56d的生长实验，每个水平3个重复，每个养殖单元放养初始体重为151g左右的美国红鱼20尾。饲养实验在海水网箱（1．5m×1．0m×1．0m）中进行。结果表明，随着饲料维生素E含量增加，美国红鱼饲料效率、特定生长率和成活率显著提高，美国红鱼最佳生长性能的饲料维生素E添加量为102．8mg／kg；美国红鱼血清溶菌酶和血清总补体活性随着维生素E的添加量的增加而显著升高，并且维生素E的添加量达到最高值102．8和25．3mg／kg，随后变化不明显；美国红鱼血清SOD活性随维生素E添加量的增加而显著升高，并且含量在102．8mg／kg达到最高值，随后显著下降。综上所述，美国红鱼维生素E的适宜添加量为102．8mg／kg。     

投喂阿维拉霉素对鲤免疫应答的影响

将阿维拉霉素按照一定的浓度添加到饲料中,投喂经注射接种福尔马林灭活的嗜水气单胞菌(Aerom onashydrophila)菌苗的鲤,于免疫后的第7 d、14 d、21 d、28 d和35 d检测供试鲤血液中的白细胞吞噬活性、血清中溶菌酶活性、抗体效价、补体C3含量及免疫保护率(RPS),探讨了阿维拉霉素对受免鲤免疫应答的影响。结果表明,饲料中添加阿维拉霉素(4 mg/kg和8 mg/kg),投喂较长时间(≥28 d)会降低受免鲤的血液白细胞吞噬活性、血清中的溶菌酶活性和抗体效价,减少受免鲤血清中补体C3的含量,减弱鲤抵抗嗜水气单胞菌人工感染的能力,每公斤饲料中添加8 mg的阿维拉霉素其免疫抑制作用更强。     

金丝桃素、绿原酸和硬葡聚糖对草鱼非特异性免疫功能的影响

在水温（25±2）℃下,给饲养在网箱（1.0m×0.5m×1.0m）中体质量（110±5）g的草鱼（Ctenopharyngodon idellus）投喂添加了金丝桃素（0、0.066%、0.132%）、绿原酸（0、0.04%、0.08%）和硬葡聚糖（0、0.2%、0.4%）饲料,以基础饲料组为对照组,探讨三种添加剂对草鱼幼鱼血清溶菌酶活性、白细胞吞噬率和血清补体C3含量的影响。结果表明：0.2%硬葡聚糖组草鱼溶菌酶活性最高,显著高于对照组（P＜0.05）,饲喂35d后溶菌酶活性达到峰值,而金丝桃素和绿原酸对草鱼幼鱼血清溶菌酶活性没有显著性影响;饲料中添加0.08%绿原酸组草鱼血液中白细胞吞噬率和血清补体C3含量均显著高于对照组（P＜0.05）,但与添加0.2%和0.4%硬葡聚糖组没有显著性差异（P＞0.05）;添加0.132%金丝桃素组的血清中补体C3含量在最低,且显著低于对照组（P＜0.05）。饲料中添加0.08%绿原酸和0.2%硬葡聚糖可有效增强草鱼幼鱼非特异免疫功能。     

饲料VC 对草鱼生长、肌肉品质及非特异性免疫的影响

采用维生素C(Vc,以Vc磷酸酯为Vc源)添加量分别为50mg/kg、100mg/kg、150mg/kg、200mg/kg、300mg/kg饲料的配合饲料,喂养体质量(42.4±5.0)g的草鱼(Ctenopharyngodon idellus)60d,以不添加Vc的基础饲料饲喂组为对照,探讨vc对草鱼生长性能、肌肉品质和非特异性免疫的影响.结果表明,饲料中添加Vc能显著提高草鱼增重率,降低饲料系数,当Vc添加量为150～200mg/kg时,草鱼生长性能最佳:随Vc添加量增加,肌肉失水率、肌纤维直径和肌原纤维耐折力呈增加趋势;肌肉胶原蛋白含量和肝脏Vc含量随Vc添加量的增加而增加;Vc添加量为150mg/kg及以上水平时,各实验组草鱼血清碱性磷酸酶(AKP)活性比对照组显著提高(p＜0.05);Vc添加量达到300mg/kg后血清溶菌酶(LSZ)活性比对照组显著提高(P＜0.05);各组间血清超氧化物歧化酶(SOD)活性差异不显著(P＜0.05).上述研究表明,饲料中添加Vc能促进草鱼生长,改善肌肉品质,增强非特异性免疫力.适宜的Vc添加量为150mg/kg饲料.     

饲料中维生素C对七彩神仙鱼仔幼鱼非特异性免疫的影响

通过投喂维生素C含量为0～2000.0mg/kg的饲料,对七彩神仙鱼仔幼鱼非特异性免疫进行了研究。结果表明,当饲料中维生素C的添加量达到500.0mg/kg(Ⅴ组)以上时,七彩神仙鱼仔幼鱼血清替代补体活力、溶菌酶活力和白细胞吞噬活性均开始显著高于对照组(P<0.05),且同一水平随时间的增加而升高。添加量达1500.0mg/kg(Ⅷ组)之后,随着饲料中维生素C添加量的进一步增加,各组数据反而呈下降趋势。可见饲料中适量添加维生素C能够提高七彩神仙鱼仔幼鱼的非特异性免疫力,维生素C缺乏和过量都会对其带来不利影响。     

大蒜素对大菱鲆幼鱼生长及抗病力的影响

在水温13～15℃、盐度30条件下,将体质量(8.12±0.03) g的大菱鲆幼鱼饲养在5.0 m×5.0 m×0.6 m的水泥池中,每池3600尾,投喂每千克饲料中分别拌入0(对照)、100、200、400、800 mg大蒜素的饲料,饲养6周。养殖试验结束时,腹腔注射鳗弧菌,连续14 d感染攻毒;饥饿24 h后,全池称量质量,尾静脉采血,测定血清中补体C3含量和溶菌酶、超氧化物歧化酶活性,研究大蒜素对大菱鲆幼鱼生长、非特异性免疫力及抗病力的影响。试验结果显示,大菱鲆幼鱼的特定生长率随着饲料中大蒜素含量的增加而逐渐升高,并在大蒜素添加量为200 mg/kg及以上时显著高于对照组(P0.05);对照组存活率显著低于其他各组(P0.05)。饲料系数随饲料中大蒜素含量的增加而逐渐降低,并在100 mg/kg及以上时显著低于对照组(P0.05),但在200 mg/kg及以上时保持稳定。血清补体C3含量随饲料中大蒜素含量的增加呈先升后降的趋势,在200、400 mg/kg组达最大值并显著高于其他各组(P0.05)。溶菌酶活力、超氧化物歧化酶活力则随大蒜素含量的增加而逐渐升高,并在大蒜素含量达400 mg/kg及以上时不再有显著变化。人工感染试验表明,400、800 mg/kg组的感染死亡率显著低于其他各组(P0.05)。综上,饲料中添加200 mg/kg的大蒜素有利于大菱鲆幼鱼生长,而400 mg/kg的大蒜素能更有效地提高其非特异性免疫力及抗病力。     

A3α肽聚糖对彭泽鲫生长及非特异免疫机能的影响

为探讨肽聚糖对彭泽鲫非特异免疫功能的影响及促长作用,将不同剂量的A3α肽聚糖添加于饵料中投喂彭泽鲫,测定鲫鱼体重、白细胞吞噬活性、血清和体表粘液溶菌酶活性,以及活菌攻毒后的免疫保护率。结果表明,添加250~550 mg/kg肽聚糖可显著提高彭泽鲫鱼白细胞吞噬活性、体表粘液及血清溶菌酶活性,但对鲫鱼生长均无明显促长效果;鲫鱼口服肽聚糖药饵后抗病能力增强,感染后的死亡率明显降低;在饵料中肽聚糖适宜添加量为250~450 mg/kg。     

壳聚糖对花鲈生长和非特异性免疫力的影响

在基础饲料中分别添加0.5%、1%和2%的壳聚糖,连续投喂花鲈(Lateolabrax japonicus)60d,探讨壳聚糖对花鲈生长和非特异性免疫力的影响。结果表明,添加0.5%和1%壳聚糖可以显著促进花鲈的生长,但是不同添加浓度对成活率均无影响。在30d时添加0.5%或1%壳聚糖能有效提高花鲈的补体活性、溶菌酶活性和吞噬活性;在60d时仅明显提高补体活性。添加壳聚糖对白细胞的数量没有影响。     

Dietary supplementation of N‐carbamylglutamate and effects on growth,intestinal enzyme activities,immunological and antioxidant abilities of juvenile yellow catfish (Pelteobagrus fulvidraco)

The effects of N‐carbamylglutamate (NCG) on growth, intestinal enzyme activities, immunological and antioxidant parameters were evaluated by a 56‐d feeding trial in Pelteobagrus fulvidraco fed diets containing NCG with 0, 250, 500, 1,000 or 2,000 mg/kg, respectively. The results showed that 250 mg/kg of NCG resulted in significantly higher weight gain, intestine fold height, intestine lipase, serum lysozyme, glutathione peroxidase and total antioxidant capacity than control (p < 0.05). However, higher intestine trypsin, arginase, arginine decarboxylase, ornithine decarboxylase, diamine oxidase activities and serum nitric oxide content were observed in 500 mg/kg NCG group compared to control or 2,000 mg/kg (p < 0.05). The survival rate, intestine muscular layer thickness, serum lysozyme and superoxide dismutase activities in 2,000 mg/kg NCG group were significantly lower than those in control and 250 mg/kg group, accompanied by the higher feed conversion ratio in the same group (p < 0.05). Together, dietary NCG level at 250 or 500 mg/kg improved growth, intestinal enzyme activities, immunological and antioxidant abilities, while high NCG level of 2,000 mg/kg had a negative effect. Quadratic regression analysis on weigh growth, diamine oxidase and lysozyme activities indicated that the recommended optimum dietary NCG level was 213.48–314.50 mg/kg of the dry diet.     

Effects of dietary supplementation of A3α-peptidoglycan on innate immune responses and defense activity of Japanese flounder (Paralichthys olivaceus)

To determine the effect of dietary supplementation of A3α-peptidoglycan (A3α-PG), extracted from Bifidobacterium sp. cell wall, on the immune responses of Japanese flounder (Paralichthys olivaceus) and explore a possible influence of doses and administration length, a 40-day feeding trial was conducted to evaluate graded levels (0, 0.5, 1, 2, 4, 8 and 16 g A3α-PG/kg diet) in the diet of juvenile Japanese flounder, followed by a challenge with Vibrio anguillarum by intraperitoneal injection. Growth, serum lysozyme, hemolytic complement activity, blood leucocyte phagocytic activity, respiratory burst, and total serum protein were monitored at intervals of 10, 20, 30 and 40 days.Growth, serum lysozyme, hemolytic complement activity, blood leucocyte phagocytic activity of juvenile Japanese flounder were generally enhanced by dietary supplementation of 1, 2, 4 and 8 g A3α-PG/kg diet and also enhanced immune responses, but not growth. The beneficial influence of A3α-PG on most of the tested immune responses were dose- and/or administration length-dependent except serum lysozyme, which was only stimulated by higher doses (more than 2 g A3α-PG/kg) after 40 days feeding. No significant influence of dietary supplementation of 0.5 g A3α-PG/kg on innate immunity was observed on juvenile fish. The highest dose explored in the present study, 16 g A3α-PG/kg, also failed to show any significant influences, although no obvious pathology was observed. Dietary supplementation of A3α-PG showed protection against V. anguillarum. The present study showed an immunomodulatory effect of dietary supplementation of A3α-PG and the potential use in health management of cultured economic fish species such as Japanese flounder.     

Enhanced haematological and immune responses in common carp Cyprinus carpio fed with olive leaf extract‐supplemented diets and subjected to ambient ammonia

The aim of the present study was to evaluate the potential effects of olive leaf (Olea europea L.) extract (OLE) on common carp (Cyprinus carpio) health in response to ambient ammonia toxicity. Fish were fed with experimental diets containing OLE (0, 1, 5 and 10 g/kg) for 60 days followed by a 3‐hr challenge with ammonia (0.5 mg/L unionized ammonia‐N). Results showed that haemoglobin levels, differential leucocyte counts and mean corpuscular haemoglobin concentration were not affected by dietary OLE levels and ammonia challenge. Ammonia challenge significantly increased red blood cells and decreased blood mean corpuscular volume, mean corpuscular haemoglobin, plasma lysozyme, complement and bactericidal activities. Plasma lysozyme, complement and total immunoglobulin values improved by 5 and/or 10 g OLE/kg supplementation. Before the ammonia exposure, the 5 and 10 g OLE/kg treatment significantly increased blood white blood cell, but there was no significant difference among the treatments after the ammonia exposure. Ammonia exposure significantly increased plasma malondialdehyde levels; however, 1 and 5 g OLE/kg treatments had significantly lower values compared to the other treatments. The present results suggest that 1 g OLE/kg diet may improve fish health and reduce the adverse effects of ammonia toxicity on common carp.     

茯苓多糖对中华鳖非特异性免疫功能的免疫调节作用

研究了口服茯苓多糖对中华鳖(Trionyxsinensis)非特异性免疫功能的影响。试验共分3个组,在基础饲料中添加20·0mg/kg茯苓多糖作为试验组,添加500·0mg/kg酵母细胞壁作为免疫刺激剂对照组,以投喂基础饲料作为空白对照组。连续投喂28d后,测定中华鳖血液中白细胞的吞噬活性、血清溶菌活力和补体活性。结果表明:在中华鳖饲料中添加茯苓多糖和酵母细胞壁能显著提高中华鳖白细胞的吞噬活性(t检验,P<0·05),而2个试验组之间中华鳖血液中白细胞的吞噬活性没有显著差异(t检验,P>0·05);2个试验组中华鳖血清中补体C3和C4的活性与对照组之间呈显著差异(t检验,P<0·05),而试验组之间无显著性差异(t检验,P>0·05)。本研究结果说明在中华鳖饵料中添加茯苓多糖和酵母细胞壁对中华鳖的非特异性免疫功能有增强作用。     

大黄素、维生素C及其配伍对团头鲂感染嗜水气单胞菌后生理生化指标的影响

为综合评价大黄素、高剂量维生素C及其配伍对团头鲂(Megalobrama amblycephala Yih)抗嗜水气单胞菌感染能力的影响,选取1 200尾健康的团头鲂,体质量为(133.44±2.11)g,随机分成4组,其中1组为对照组,投喂基础日粮,另外3组在基础日粮中分别添加60mg/kg大黄素、700 mg/kg维生素C、60mg/kg大黄素+700mg/kg维生素C(配伍组).饲养60 d后,经腹腔注射感染嗜水气单胞菌,并在攻毒前后检测团头鲂血液和肝脏的生化指标以及肝脏2种热休克蛋白70s(HSP70s)mRNA的表达水平;另从各池中取10尾鱼进行同样的攻毒试验,统计攻毒后各时间点鱼的累积死亡率.结果表明,攻毒后,与对照组相比,大黄素、维生素C组不同程度地提高了血清总蛋白(TP)、溶菌酶(LSZ)和碱性磷酸酶(AKP)的水平,肝脏超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性以及HSC70和HSP70 mRNA的表达水平,降低了血清皮质醇(COR)、血糖(GLU)、谷丙转氨酶(GPT)、谷草转氨酶(GOT)、甘油三酯(TG)以及肝脏丙二醛(MDA)的水平;配伍组中,这些指标的变化趋势虽与上述类似,但大多与对照组的差异不显著(P＞0.05),且未表现出协同增效作用.此外,各组鱼血清胆固醇(CHOL)的含量在攻毒前后的差异均不显著(P＞0.05).统计也表明,大黄素和维生素C组鱼的累积死亡率在攻毒后24 h、48 h均显著低于对照组(P＜0.05),而配伍组试验鱼的累积死亡率与对照组差异均不显著(P＞0.05).由此可见,在基础日粮中添加大黄素60 mg/kg或维生素C 700 mg/kg,可提高鱼体的非特异性免疫力、抗氧化能力以及2种HSP70s mRNA的表达水平,增强鱼体抗病原菌感染的能力.二者配伍则效果不佳.     

Effects of dietary lysolecithin on growth performance,feed utilization,intestinal morphology and metabolic responses of channel catfish (Ictalurus punctatus)

This study investigated the effects of dietary lysolecithin on growth performance, feed utilization and metabolic responses of channel catfish (Ictalurus punctatus). Fish (initial weight: 14.77 ± 0.45 g) were randomly fed one of five practical diets supplemented with graded levels of lysolecithin (0, 125, 250, 375 and 500 mg/kg) in quadruplicate groups for 10 weeks. Results showed that no significant differences in weight gain, condition factor and viscerosomatic index among all the treatments. Fish fed diet supplemented with 250 mg/kg lysolecithin had significantly decreased feed conversion ratio and significantly increased protein efficiency ratio compared to that fed the control diet. The group with 250 mg/kg of dietary lysolecithin had higher protein and lower lipid contents in the whole body, and lower lipid content in the liver than those in the control group. Groups supplemented with 250–500 mg/kg of dietary lysolecithin had significantly higher gastric and intestinal lipase activities than the control group. Dietary lysolecithin at the level of 250 mg/kg significantly increased the activities of Na⁺, K⁺‐ATPase, alkaline phosphatase, total antioxidative capacity, total superoxide dismutase, glutathione peroxidase and catalase and significantly decreased the content of malondialdehyde compared to the control diet. In conclusion, dietary supplementation of lysolecithin could confer benefits of feed utilization, body composition and antioxidative capacity of channel catfish.     

饲料中添加L-肉碱对吉富罗非鱼生长、肝脏脂肪代谢及抗氧化能力的影响

分别在3组等氮等能的吉富罗非鱼(GIFT,Oreochromis niloticus)饲料中添加不同水平的L-肉碱[0(对照组)、150和300 mg/kg],试验选用初始体重为(8.21±0.33)g的幼鱼投喂9周,探讨L-肉碱对吉富罗非鱼生长、体成分、血清生化指标、肝脏脂肪代谢酶活性和抗氧化能力的影响。结果表明:添加150或300 mg/kg L-肉碱显著提高了罗非鱼增重率(WGR)和特定生长率(SGR),显著降低了实验鱼肝体比(HSI)和脏体比(VSI);添加150 mg/kg L-肉碱组WGR和SGR最高,HSI和VSI最低。添加150 mg/kg L-肉碱显著提高了鱼体肥满度(CF)。饲料系数(FCR)和存活率(SR)在对照组和实验组间无显著差异。添加150或300 mg/kg L-肉碱显著提高了鱼体肝脏中粗蛋白含量,添加150 mg/kg L-肉碱显著降低了肝脏粗脂肪含量。添加150或300 mg/kg L-肉碱时,血清甘油三酯(TG)含量显著降低,肝脏脂蛋白脂酶(LPL)、肝脂酶(HL)、总酯酶(LPL)和脂肪酶(LPS)活性显著上升,肝脏过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-PX)活性显著增加,肝脏丙二醛(MDA)含量显著下降。添加300 mg/kg L-肉碱显著提高了鱼体肝脏超氧化物歧化酶(SOD)活性和溶菌酶(LZM)活性。综上,饲料中添加适量L-肉碱对提高吉富罗非鱼生长性能,促进其脂肪代谢和提高鱼体抗氧化能力有良好效果。基于L-肉碱对罗非鱼增重率和特定生长率的影响,推荐L-肉碱在吉富罗非鱼饲料中的添加量为150 mg/kg。