Comparative Analysis on Growth and Morphology in Yangtze River ♀,Zhujiang River ♂ and Their F_1 Hybrids of Juvenile Grass Carp

[ Objective] The aim of this study was to investigate the growth and morphological characteristics of juvenile hybrids of grass carp. [Method] Three inbred generations of YR （Yangtze River stock ♀×Yangtze River stock ♂ ）, ZR （Zhujiang River stock ♀ ×Zhujiang River stock♂ ） and hybrids F1 （ Yangtze River stock ♀ × Zhujiang River stock ♂ ） were established, and their growth or morphological data were also measured. [ Result] The orders of body weight, standard length and absolute growth rate were F1 〉 ZR 〉 YR. No significant difference was found in body weight or standard length of 50 day-old generations （ P〉0. 05）, while there was an extremely significantly difference in those of 170 day-old generations （ P 〈0.01 ）. However, the absolute growth rate of F1 was 20.00% and 50.00% higher than that of ZR and YR respectively, and no significant difference was found between F1 and ZR （ P 〉 0.05）, but significant difference between F1 and YR （ P 〈 0.05）. F1 showed a significant hybrid vigor with rate of 20.09%. There was no significant difference among three inbred generations in standard length/total length （ P 〉 0.05）, while significant difference in head length/total length, body height/standard length and body width/standard length （ P 〈 0.05）, which indicated that F1 had the characteristics of shorter head, higher and wider body. [ Conclusion]F1 has advantages in growth performance and morphological characteristics.

In Situ Determination of the Effect of Drilling Noise and Vibration on Growth of Grass Carp, Myloparyngodon Piceus

The study is carried out on the effect of drilling noise and vibration on growth of grass carp, Myloparyngodon Piceus, by using cut-fin marking method in situ. Compared with other methods, the method is more appropriate, for its operation is simpler and more data may be obtained under the same condition. The results show that drilling noise and vibration have significant effect on the growth of grass carp. Critical equivalent noise and vibration grade ( Nleq and Vleq ) are about 84.4 dB and 90.2 dB, and the affecting radius is about 8.5 m. The effect of drilling noise and vibration could be influenced by some factors, such as duration of pollution and body weight of grass carp, etc. Grass carp’s growth could rapidly recover after removing drilling noise and vibration, indicating that the drilling noise and vibration do not damage the fish organs and the effect is reversible. Therefore, the effect mechanism may be due to the activating response of non-hearing system.

Effects of Nano-sustained Release Sodium Butyrate on Growth and Intestinal Cell Proliferation of Grass Carps

Taking grass carps with the initial weight of about 20g as the research object,the basic feeds of grass carps were added with0.0%,0.1%,0.3%,0.6%,0.8%,and 1% of nano-sustained release sodium butyrate to prepare 6 types of experimental feeds with equal nitrogen and energy.The effects of different concentrations of nano-sustained release sodium butyrate were surveyed on growth and intestinal cell proliferation of grass carps.The experiment was carried out in cages with 50 carps per cage,and each treatment was repeated 3 times for60 days.Experimental results indicated that the addition of nano-sustained release sodium butyrate significantly promoted the growth of grass carps and significantly increased the ratio of intestinal villus to crypt depth.When the addition of nano-sustained release sodium butyrate was0.6%,the weight increase rate,specific growth rate,fullness and intestinal villus height of grass carps were the highest,which was significantly higher than that of the control group(P < 0.05).The study results indicated that addition of appropriate amount of nano-sustained release sodium butyrate can promote the growth of grass carps through increasing the intestinal villus height,and the suitable addition dosage was0.6%.

Growth Performance of Hybrid Progenies of Grass Carp (Ctenopharyngodon idella) Populations from Different Geographical Origins

[Objective] This study aimed to evaluate growth performance of hybrid progenies of 10 grass carp （Ctenopharyngodon idella） populations from different ge- ographical origins （Foshan population, Zhaoqing population, Jingzhou population 1, Jingzhou population 2, Jingzhou population 3, Ezhou population, Yiyang population, Changsha population 1, Changsha population 2 and Jiangsu population）. [Method] Fifteen hybrid combinations were established with these ten grass carp populations and cultured in the same pond. The body mass of hybrid progenies was measured at the age of 4, 7, 8, 10, 12, 15 and 18 months, respectively. Using body mass at the age of 4 months as a concomitant variable, the growth performance of proge- nies from different hybrid combinations was analyzed by covariance analysis. [Re- suit] The average body mass of hybrid progenies of Jingzhou population 2 c2 x Foshan population $ reached the maximum （1 892.90 g） at the age of 18 months, which was 3.51%-32.36% higher than that of other hybrid progenies. Multiple com- parison analysis showed that average body mass of hybrid progenies of Jingzhou population 2 2 x Foshan population ♂ and Jingzhou population 1 ♀× Foshan population ♂ was significantly higher than that of other hybrid progenies （P〈0.05）. [Conclusion] In the production process, Jingzhou population 2 ♀ × Foshan popula- tion 5 and Jingzhou population 1 ♀×Foshan population ♂ can be used to pro- duce high-quality fries, thereby greatly improving economic benefits. This study laid the foundation for establishment of rapid-growing grass carp core populations.

Assessment of black soldier fly(Hermetia illucens)larvae meal as a potential substitute for soybean meal on growth performance and flesh quality of grass carp Ctenopharyngodon idellus

A 90-day feeding trial was conducted to assess the effects of black soldier fly larvae meal(BSFLM)as a replacement for soybean meal(SM)on growth performance and flesh quality of grass carp.A total of 420grass carp(299.93±0.85 g)were randomly divided into 7 groups(triplicate)and fed 7 diets with SM substitution of 0%(SM,control),15%(BSFLM15),30%(BSFLM30),45%(BSFLM45),60%(BSFLM60),75%(BSFLM75)and 100%(BSFLM100)by BSFLM.The growth performance of grass carp in the BSFLM75 and BSFLM100 groups were significantly lower compared to other groups(P<0.05).The mid-gut villus height was the lowest in the BSFLM100 group(P<0.05).Muscle nutritional value was improved due to increased DHA(docosahexaenoic acid),EPA(eicosapentaenoic acid),total HUFA(highly unsaturated fatty acids)and glycine levels,and reached the optimum in the BSFLM100 group(P<0.05).According to the results of principal component analysis and weight analysis of muscle texture and body color,all the BSFLM diets except BSFLM15 could improve muscle texture and body color and reached the optimum level in the BSFLM100 group.Muscle drip loss and hypoxanthine content were the lowest and muscle antioxidant capacity was the highest in the BSFLM75 group,and water-and salt-soluble protein contents reached the optimum level in the BSFLM60 group(P<0.05).Dietary BSFLM significantly reduced muscle fiber area and diameter,and increased muscle fiber density and the proportion of small fiber(diameter<20μm)(P<0.05).Additionally,sarcomere lengths in the BSFLM75 and BSFLM100 groups were significantly higher than that in the SM group(P<0.05).The m RNA relative expression levels of Myo D,Myf5,My HC and FGF6b were remarkably up-regulated at an appropriate dietary BSFLM level(P<0.05).In conclusion,BSFLM could replace up to 60%SM without an adverse effect on growth performance and improve the flesh quality of grass carp.The optimum levels of dietary BSFLM were 71.0 and 69.1 g/kg diet based on the final body weight and feed conversion ratio.The flesh quality was optimal when dietary SM was completely replaced with BSFLM(227 g/kg diet).

The influence of graded levels of available phosphorus on growth performance,muscle antioxidant and flesh quality of young grass carp(Ctenopharyngodon idella)

Growth, muscle composition, meat quality characteristics and antioxidant capacity in muscle of young grass carp(Ctenopharyngodon idella)(initial weight 282.9 ± 3.3 g) fed graded levels of phosphorus(1.0,2.5, 3.8, 5.6, 7.8 and 9.5 g/kg diet) for 8 wk were investigated. Results indicated that percentage weight gain, feed intake, feed efficiency, serum phosphorus and alkaline phosphatase were improved with optimal phosphorus supplementations(P < 0.05). Muscle protein content and water holding capacity were significantly elevated, while moisture, lipid and ash contents were significantly decreased with dietary phosphorus to a certain level(P < 0.05). The meat shear force value and hydroxyproline content were not influenced by different levels of phosphorus. Muscle anti-hydroxyl radical, superoxide dismutase, catalase, glutathione S-transferase activities and glutathione content were significantly improved(P < 0.05). Conversely, anti-superoxide anion, glutathione reducase and glutathione peroxidase activities were decreased(P < 0.05) with dietary phosphorus to a certain level. These results indicated that suitable dietary phosphorus improved growth performance, meat quality and muscle antioxidant capacity. Dietary available phosphorus requirement of young grass carp for percentage weight gain was4.0 g/kg diet.

Transcriptomic analysis reveals growth-related genes in juvenile grass carp,Ctenopharyngodon idella

Grass carp has the highest production yield among all the farmed fish species around the world.But the molecular and genetic basis of growth traits is inadequately understood in this fish.In the present study,we apply whole-transcriptome sequencing to identify genes whose expression is different between fast and slow growing grass carp.We identified 1178 differentially expressed genes(DEGs),among which 270 were upregulated in the fast growing group and 908 upregulated in the slow growing group.The GO enrichment analysis revealed that DEGs was significantly enriched in protein synthesis and export machinery,cell division and development and metabolism,suggesting that cell division and metabolism may play key roles in development processes of fish.KEGG pathway analysis showed that MAPK signaling pathway may play a prominent role in growth difference.In addition,the majority of genes in immune responses related pathway were upregulated in the slow growing individuals.These results provide some valuable resources for understanding the molecular mechanisms of growth traits in fish.

Dietary curcumin alleviates intestinal damage induced by ochratoxin A in juvenile grass carp(Ctenopharyngodon idella):Necroptosis and inflammatory responses

Ochratoxin A(OTA)is one of the most common pollutants in aquatic feed.As a first line of defense,intestinal barriers could be utilized against OTA in order to prevent disorders.Natural product supplementation is one of the most popular strategies to alleviate toxicity induced by mycotoxins,but there is a lack of knowledge about how it functions in the teleost intestine.In this study,720 juvenile grass carp of about 11 g were selected and four treatment groups(control group,OTA group,curcumin[Cur]group,and OTA+Cur group)were set up to conduct a 60-day growth test.After the test,the growth performance and intestinal health related indexes of grass carp were investigated.The addition of dietary Cur could have the following main results:(1)inhibit absorption and promote efflux transporters mRNA expression,reducing the residuals of OTA,(2)decrease oxidative stress by reducing oxidative damage and enhancing the expression of antioxidant enzymes,(3)promote mitochondrial fusion proteins to inhibit the expression of mitotic proteins and mitochondrial autophagy proteins and enhance mitochondrial function,(4)reduce necroptosis-related gene expression through inhibiting the tumor necrotic factor receptor-interacting protein kinase/mixed lineage kinase domain-like pathway,(5)reduce the expression of pro-inflammatory factors by inhibiting the Toll-like receptor 4/nuclear factor-κB signaling pathway to alleviate the intestinal inflammatory response.In summary,the results suggested that Cur could alleviate OTA-induced intestinal damage by enhancing antioxidant capacity and mitochondrial function as well as reducing necroptosis and inflammation in the grass carp intestine.This study provided a theoretical basis and production implications for dietary Cur that could improve growth performance and alleviate the intestinal damage induced by OTA in fish.

The role of vitamin E in polyunsaturated fatty acid synthesis and alleviating endoplasmic reticulum stress in sub-adult grass carp(Ctenopharyngodon idella)

Vitamin E(VE)is an essential lipid-soluble vitamin that improves the fish flesh quality.However,the underlying molecular mechanisms remain unclear.This study aimed to investigate the effects of VE on growth performance and flesh quality in sub-adult grass carp(Ctenopharyngodon idella).A total of 450fish(713.53±1.50 g)were randomly divided into six treatment groups(three replicates per treatment)and fed for nine weeks with different experimental diets(dietary lipid 47.8 g/kg)that contained different levels of VE(5.44,52.07,96.85,141.71,185.66,and 230.12 mg/kg diet,supplemented as dl-a-tocopherol acetate).Notably,the treatment groups that were fed with dietary VE ranging from 52.07 to230.12 mg/kg diet showed improvement in the percent weight gain,special growth rate,and feed efficiency of grass carp.Moreover,the treatment groups supplemented with dietary VE level of 141.71,185.66,and 230.12 mg/kg diet showed enhancement in crude protein,lipid,and a-tocopherol contents in the muscle,and the dietary levels of VE ranging from 52.07 to 141.71 mg/kg diet improved muscle pH24h and shear force but reduced muscle cooking loss in grass carp.Furthermore,appropriate levels of VE(52.07 to 96.85 mg/kg diet)increased the muscle polyunsaturated fatty acid content in grass carp.Dietary VE also increased the mRNA levels of fatty acid synthesis-related genes,including fas,scd-1,fad,elovl,srebp1,pparγ,and lxra,and up-regulated the expression of SREBP-1 protein.However,dietary VE decreased the expression of fatty acid decomposition-related genes,including hsl,cpt1,acox1,and ppara,and endoplasmic reticulum stress-related genes,including perk,ire1,atf6,eif2a,atf4,xbp1,chop,and grp78,and down-regulated the expression of p-PERK,p-IRE1,ATF6,and GRP78 proteins.In conclusion,dietary VE increased muscle fatty acid synthesis,which may be partly associated with the alleviation of endoplasmic reticulum stress,and ultimately improves fish flesh quality.Moreover,the VE requirements for sub-adult grass carp(713.53 to 1590.40 g)were estimated to be 124.9 and 122.73 mg/kg diet based on percentage weight gain and muscle shear force,respectively.

Adaptation strategies of juvenile grass carp(Ctenopharyngodon idella)facing different dissolved oxygen concentrations in a recirculating aquaculture system

Fishes exposed to different dissolved oxygen concentrations over prolonged time periods have different susceptibility and adaptation mechanisms.In this study,healthy grass carp with an average weight of 214.6±18.7 g were selected for long-term culture in recirculating aquaculture systems at three different dissolved oxygen concentrations,i.e.,3.00 mg/L[(2.57±0.33)mg/L,DO_(2.57)),5.00 mg/L[(4.61±0.11)mg/L,DO_(4.61)],which was the control group,and 7.00 mg/L[(6.50±0.48)mg/L,DO_(6.50)].Blood,gill,muscle,and liver samples were collected after 60 days.Using hematoxylin-eosin(HE),alcian blue periodic acid Schiff(AB-PAS)staining,determination of respiratory metabolism enzyme activity,and fluorescent quantitative PCR,the adaptability of juvenile grass carp facing different dissolved oxygen levels were explored.The results showed that the respiration rate increased,and hemoconcentration and hemoglobin(Hb),electrolyte and pH changed at DO2.57.Furthermore,gill lamellae became thinner and longer,the distance between them increased,the mucus on them decreased and the interstitial cell mass decreased.In addition,the relative expression of apoptosis-related genes bcl-2 and bcl-xl in gill tissue decreased,while caspase-3 and bax increased.In muscles and liver tissues,lactate dehydrogenase(LDH)activity and lactic acid content(LA)increased,pyruvate dehydrogenase(PDH)activity decreased,and genes related to the respiratory metabolic enzymes PDH-A4 and PDH-E1α also changed accordingly.The oxygen consumption rate decreased significantly(P<0.05).At DO_(6.50),the distance between gill lamellae,numbers of red blood cells(RBC)and the content of hemoglobin decreased wheras the mucus on gill lamellae increased.The activity of PDH,the expression of PDH-E1a in liver and oxygen consumption rate increased.Different dissolved oxygen concentrations affected the respiratory behavior,gill tissue structure,blood transport capacity and tissue enzyme activity of juvenile grass carp.In summary,juvenile grass carp showed different adaptation strategies when facing different dissolved oxygen concentrations over prolonged periods in recirculating aquaculture systems.

Effects of Bacillus subtilis on hepatic lipid metabolism and oxidative shess response in grass carp(Ctenopharyngodon idellus)fed a high-fat diet

Bacillus subtilis is widely used in aquaculture as a probiotic.However,few studies have been conducted to examine the effect of B.subtilis on liver lipid metabolism.A total of 135 healthy grass carp(50.24±1.38 g)were randomly divided into three groups:control(Con),high-fat diet(HF),and high-fat diet+B.subtilis(HF4-B.subtilis),and fed for 8 weeks.The results showed that compared with the HF group,the weight gain rate(WGR)significantly increased(Pc0.05)and the hepatic lipid content,serum low-density lipoprotein cholesterol(LDL-C),and aspartate aminotransferase(AST)decreased in the group supplemented with B.subtilis(P<0.05).Moreover,the hepatic mRNA expression of fatty acid synthase(FAS)was significantly down-regulated and the carnitine palmitoyl transferases(CPTlala)were up-regulated in the HF+B.subtilis group compared to the HF group(P<0.05),respectively.Additionally,in the HF+B.subtilis group,glutathione(GSH)significantly increased(Pv 0.()5),while hydrogen peroxide(H2O2)and malondialdehyde(MDA)contents significantly decreased compared to the HF group(P v0.05).B.subtilis may reduce the hepatic lipid content by inhibiting its synthesis and promoting p-oxidation of fatty acids.B.subtilis may also alleviate dyslipidaemia and prevent oxidative damage in the liver caused by the high-fat diet of grass carp.Hence,dietary supplementation with B.subtilis shows promise as a therapeutic or preventive tool against fatty liver disease.

不同脂肪源对草鱼生长性能及血液生化指标的影响

本试验将不同脂肪源添加到草鱼日常饲料中,研究对其生长性能和血液生化指标的影响。试验将450尾草鱼平均分为5组,分别添加鱼油、猪油、豆油、玉米油和混合油为脂肪源,试验为期30d。结果表明,与对照组相比,在日粮中添加不同种类的脂肪源对草鱼末重、增重率有显著影响(P <0.05),其中添加玉米油为脂肪源的试验组对提高草鱼生长性能效果最显著,草鱼平均增重率比对照组显著提高12.23%(P <0.05);其次,在日粮中添加不同种类的脂肪源对草鱼鱼体营养成分也有显著影响(P <0.05),添加玉米油脂肪源的试验组肌肉蛋白指标与对照组相比差异最显著,比对照组显著提高7.16%(P <0.05)。最后,在日粮中添加不同水平的脂肪源对草鱼血清中IgA、IgG、IgM等免疫指标均有显著影响(P <0.05),其中添加玉米油脂肪源的试验组血清免疫指标与对照组相比差异最显著,IgA、IgG、IgM分别提高了17.7%、20.9%和36.8%(P <0.05)。本试验结果表明,在日粮中添加5%玉米油作为脂肪源,对草鱼的促生长效果最显著,可使草鱼的增重及鱼体肌肉蛋白含量最高。

氨基酸微量元素螯合物对草鱼生长性能、血清生化指标及微量元素沉积的影响

为研究饲料中添加氨基酸微量元素螯合物对草鱼(Ctenopharyngodon idellus)生长性能、微量元素沉积及血清生化指标的影响,本试验以初始体重为(40.05±0.05)g的草鱼为研究对象,共计720尾随机分为6组,对照组(CON组)饲喂不添加微量元素的基础饲料,无机微量元素添加组(IT100组)饲喂在基础饲料中添加草鱼微量元素需要量的100%无机微量元素铜、铁、锌、锰的试验饲料,氨基酸微量元素螯合物添加组(OT25组、OT50组、OT75组和OT100组)饲喂以25%、50%、75%和100%氨基酸微量元素螯合物等比例替代IT100组饲料中无机微量元素的试验饲料,每组3个重复,每个重复40尾鱼,养殖8周。结果表明:1)不同组之间草鱼的存活率、肥满度、肝体比和脏体比没有显著差异(P>0.05)。与CON组相比,IT100组、OT75组增重率显著升高(P<0.05),而饲料系数的变化趋势则与之相反,OT50组和OT75组显著降低(P<0.05)。2)与CON组相比,IT100组、OT50组、OT75组、OT100组肠道胰蛋白酶、淀粉酶和脂肪酶活性均显著升高(P<0.05),OT25组肠道的淀粉酶活性显著升高(P<0.05)。3)根据草鱼脊椎骨微量元素沉积量的二次回归方程,氨基酸微量元素螯合物内元素分别在添加水平为铜67.53%、铁58.22%、锌58.68%、锰56.07%时到达100%无机微量元素效价。4)与CON组相比,IT100组的血清中总胆固醇、低密度脂蛋白胆固醇、尿素氮含量及谷丙转氨酶、谷草转氨酶活性显著降低(P<0.05),血清补体3、高密度脂蛋白胆固醇含量和碱性磷酸酶活显著降低(P<0.05)。与CON组比较,OT各组血清甘油三酯含量均显著降低(P<0.05),OT100组血清总胆固醇、尿素氮含量及谷丙转氨酶活性显著降低(P<0.05),OT75组和OT100组血清低密度脂蛋白胆固醇含量和谷草转氨酶活性显著降低(P<0.05),OT100组血清碱性磷酸酶活性显著上升(P<0.05)。综上所述,饲料中添加适宜比例的氨基酸微量元素螯合物能提高草鱼生长性能、营养消化吸收和脊椎骨内微量元素沉积,其中75%的氨基酸微量元素螯合物替代比例为最适替代比例。

以黄粉虫为主要蛋白源时草鱼摄食、生长及抗氧化能力对饲料蛋白质含量的响应研究

实验旨在探究以黄粉虫为主要蛋白源时草鱼摄食、生长及抗氧化能力对饲料蛋白含量的响应。以黄粉虫为主要蛋白源,分别设计6组不同蛋白质水平(25.25%、29.43%、33.38%、37.96%、41.40%、45.70%,分别命名为TMF1、TMF2、TMF3、TMF4、TMF5组和TMF6组)的草鱼饲料,以初始体重(3.63±0.01)g的草鱼苗为实验对象进行为期8周的养殖实验,探究不同黄粉虫蛋白质水平对草鱼生长性能和抗氧化能力的影响。结果表明:(1)不同黄粉虫的添加量除了对存活率和饲料效率的影响不显著外(P>0.05),草鱼的特定生长率、增重率和蛋白质效率都会随着黄粉虫添加量的增加而减少,且TMF1组的上述指标均显著高于TMF4、TMF5和TMF6组(P<0.05),草鱼的摄食率则随着黄粉虫添加量的增加呈先增加后减少的变化趋势;(2)不同黄粉虫含量的饲料对草鱼的肥满度和空壳率没有显著影响(P>0.05),但草鱼的肝体比和肠脂比会随着黄粉虫含量的增加先上升后下降,TMF2组的肠脂比显著高于其他组(P<0.05);(3)草鱼血清中的总蛋白含量随着黄粉虫添加量的增加先上升后下降,TMF4组的总蛋白含量除与TMF3组相近外,显著高于其他组(P<0.05),胆固醇则是在TMF1组显著低于其他组,谷草转氨酶活性在TMF4和TMF6组显著高于TMF1、TMF2和TMF3组(P<0.05),而三酰甘油含量则是随着黄粉虫的添加量的增加而降低,且TMF1组三酰甘油含量显著高于TMF5和TMF6组(P<0.05),血糖含量仅在TMF1组高于TMF2组(P<0.05),其他组间无显著差异(P>0.05);(4)草鱼肝胰脏的超氧化物歧化酶活性、总抗氧化能力、丙二醛含量和谷胱甘肽过氧化物酶的活性随着黄粉虫添加量的增加而降低,其中TMF1组谷胱甘肽过氧化物酶活性和丙二醛含量显著高于其他组(P<0.05),但是黄粉虫添加量的增加对过氧化氢酶的活性没有显著影响(P>0.05)。本研究表明,草鱼饲料中以黄粉虫为主要蛋白源时,其蛋白质含量不宜超过25.25%,较高的黄粉虫添加量对草鱼的摄食、生长和抗氧化性能产生负面影响。

复合酸化剂对草鱼生长性能、非特异性免疫力及血清生化指标的影响

试验旨在研究不同水平的复合酸化剂对草鱼生长性能、非特异性免疫力及血清生化指标的影响。试验选择480尾体重相近的草鱼,随机分为4组,每组3个重复,每个重复40尾。对照组草鱼饲喂基础饲料,试验组草鱼分别饲喂含有0.1%(0.1%复合酸化剂组)、0.2%(0.2%复合酸化剂组)和0.4%(0.4%复合酸化剂组)复合酸化剂的饲料。试验期8周。结果显示,与对照组相比,0.2%复合酸化剂组草鱼末重、增重率、特定生长率显著提高(P<0.05),饲料系数显著降低(P<0.05)。0.1%复合酸化剂组和0.2%复合酸化剂组草鱼肝体比显著提高(P<0.05)。与对照组相比,各复合酸化剂组草鱼肌肉中的粗脂肪含量均显著升高(P<0.05),0.2%复合酸化剂组草鱼肌肉中水分含量显著降低(P<0.05)。与对照组相比,0.2%复合酸化剂组和0.4%复合酸化剂组草鱼血清溶菌酶(LZM)活性、甘油三酯(TG)含量显著升高(P<0.05);各复合酸化剂组草鱼血清免疫球蛋白M(IgM)含量升高(P<0.05);0.2%复合酸化剂组草鱼血清尿素氮(BUN)含量显著降低(P<0.05),总蛋白(TP)、葡萄糖(GLU)含量和碱性磷酸酶(AKP)活性显著升高(P<0.05)。研究表明,草鱼生产中添加适量的复合酸化剂可提高生长性能,改善体成分,增强机体免疫力,改善部分血清生化指标,且复合酸化剂的适宜添加水平为0.2%。

α-单月桂酸甘油酯对草鱼生长性能、肠道免疫活性物质及肠道炎症反应基因表达的影响

文中旨在探究α-单月桂酸甘油酯(α-GML)对草鱼生长性能、肠道免疫活性物质及肠道炎症反应基因表达的影响。试验将720尾初重(213.74±7.83)g的草鱼随机分为4组,试验日粮分别在基础日粮基础上添加0、200、400和800 mg/kg α-GML。结果表明,与对照组相比,400和800 mg/kg α-GML组草鱼FBW分别显著提高7.29%和8.71%(P<0.05),PWG分别显著提高10.77%和10.80%(P<0.05),SGR分别显著提高5.94%和5.94%(P<0.05),FE分别显著提高10.02%和11.01%(P<0.05);此外,α-GML对草鱼FI无显著影响(P>0.05)。添加400和800 mg/kg α-GML组草鱼前肠LZ活性显著提高(P<0.05);200~800 mg/kg α-GML组草鱼中肠IgM含量显著提高(P<0.05);添加400和800 mg/kg α-GML组草鱼后肠ACP活性显著提高(P<0.05);此外,添加α-GML对草鱼前肠ACP活性、IgM含量,中肠LZ和ACP活性,后肠LZ活性、IgM含量均无显著影响(P>0.05)。200 mg/kg α-GML组草鱼后肠TNF-α和IL-6基因表达量显著降低(P<0.05);400 mg/kg α-GML组草鱼中肠IL-1β和后肠TNF-α、IL-6基因表达量显著降低(P<0.05);800 mg/kg α-GML组草鱼前肠TNF-α、中肠TNF-α、IL-1β和后肠IL-6基因表达量显著降低(P<0.05);此外,α-GML对草鱼前肠和中肠IL-6和后肠IL-1β(P>0.05)。综上所述,α-GML可通过提高草鱼肠道免疫力和功能促进草鱼生长性能的提高。在本试验条件下,α-GML的最佳剂量是400 mg/kg。

复合微生态制剂对草鱼生长性能、免疫功能及水体质量的影响

文章旨在研究复合微生态制剂(Composite Microecological Formulations,CMF)对草鱼生长性能、免疫功能及水体质量的影响。试验将240尾同批次(16.51±1.03)g的草鱼幼苗随机分为4组,分别饲喂基础饵料+0%(CMF0组)、0.1%(CMF1组)、0.2%(CMF2组)、0.3%(CMF3组)的复合微生态制剂,每组3个重复,每个重复20尾。试验为期60 d,整个试验期间不换水、不充氧、不使用消毒剂。结果:(1)与CMF0组相比,CMF2组、CMF3组草鱼的末重、增重率、特定生长率显著提高(P<0.05),饲料系数显著降低(P<0.05)。CMF2组草鱼生长性能各项指标优于CMF3组,但差异不显著(P>0.05)。(2)与CMF0组相比,CMF1组、CMF2组、CMF3组草鱼血清中超氧化物歧化酶、过氧化氢酶、溶菌酶浓度显著提高(P<0.05)。(3)与CMF0组相比,CMF1组、CMF2组、CMF3组水体中第45、60天溶解氧含量显著提高(P<0.05),同时亚硝酸盐含量显著降低(P<0.05)。与CMF0组相比,CMF2组、CMF3组水体中第30、d、第60天氨氮含量显著降低(P<0.05)。结论:不同水平的复合微生态制剂均有提高草鱼生长性能、免疫功能,以及改善水体质量的效果。综合经济效益考虑,本试验条件下复合微生态制剂的适宜添加量为0.2%。

艾叶粉对草鱼幼鱼生长性能、形体指标、肌肉营养成分、消化酶活性、非特异性免疫力及抗氧化能力的影响

本试验旨在研究艾叶粉对草鱼幼鱼生长性能、形体指标、肌肉营养成分、消化酶活性、非特异性免疫力及抗氧化能力的影响。选择体格健壮、初始体质量为(14.76±0.28)g的健康草鱼幼鱼450尾,随机分成5组,每组3个重复,每个重复30尾。各组分别饲喂在基础饲料中添加0(对照组)、2.0%(Ⅰ组)、4.0%(Ⅱ组)、8.0%(Ⅲ组)和16.0%(Ⅳ组)的艾叶粉的试验饲料。试验期70 d。结果表明:1)Ⅱ组和Ⅲ组的末重、增重率(WGR)和特定生长率(SGR)显著高于对照组(P<0.05)。2)Ⅲ组的肌肉粗蛋白质含量显著高于对照组(P<0.05)。3)Ⅱ组和Ⅲ组的肝脏碱性磷酸酶(AKP)活性显著高于对照组(P<0.05),Ⅲ组的肝脏溶菌酶(LZM)含量显著高于对照组(P<0.05)。Ⅱ组和Ⅲ组的肝脏过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性及总抗氧化能力(T-AOC)均显著高于对照组(P<0.05),丙二醛(MDA)含量显著低于对照组(P<0.05)。4)Ⅱ组、Ⅲ组和Ⅳ组的血清LZM含量显著高于对照组(P<0.05)。Ⅰ组、Ⅱ组和Ⅲ组的血清GSH-Px活性显著高于对照组(P<0.05),Ⅱ组和Ⅲ组的血清MDA含量显著低于对照组(P<0.05),Ⅲ组的血清总超氧化物歧化酶(T-SOD)活性显著高于对照组(P<0.05),Ⅰ组和Ⅱ组的血清T-AOC显著高于对照组(P<0.05)。5)Ⅱ组和Ⅲ组的肠道α-淀粉酶和胰蛋白酶活性显著高于对照组(P<0.05)。综上所述,饲料中添加适量的艾叶粉可以促进草鱼幼鱼生长,改善肌肉营养品质,提高草鱼幼鱼非特异性免疫力、抗氧化能力以及消化酶活性。综合考虑,草鱼幼鱼饲料中艾叶粉添加水平以4.0%~8.0%为宜。

高糖饲料中添加益生菌对松浦镜鲤生长性能、肠道消化酶和抗氧化酶活性及免疫基因表达的影响

本试验旨在探讨高糖饲料中添加嗜酸乳杆菌(Lactobacillus acidophilus)、动物双歧杆菌(Bifidobacterium animalis)、鼠李糖乳杆菌(Lactobacillus rhamnosus)和干酪乳杆菌(Lactobacillus casei)对松浦镜鲤生长性能和肠道健康的影响。选用初始体重为(1.51±0.02)g的松浦镜鲤450尾,随机分为5组,每组3个重复,每个重复30尾鱼。以鱼粉、酪蛋白、豆粕为蛋白质源,淀粉为糖源,糖水平为45%。5个试验组分别为对照组(G0组)、嗜酸乳杆菌组(G1组)、动物双歧杆菌组(G2组)、鼠李糖乳杆菌组(G3组)和干酪乳杆菌组(G4组)。试验周期为8周。结果表明:1)与G0组相比,G2、G3和G4组松浦镜鲤的末重和增重率均显著提高(P<0.05),G2和G3组饲料系数显著降低(P<0.05),G2组的脏体指数、肠体指数和肝体指数为各试验组中最高。2)与G0组相比,G2组全鱼粗蛋白质含量显著提高(P<0.05),肠道淀粉酶、胰蛋白酶和脂肪酶活性显著增加(P<0.05)。3)与G0组相比,各益生菌组肠道丙二醛(MDA)含量均显著降低(P<0.05),总抗氧化能力(T-AOC)和总超氧化物歧化酶(T-SOD)活性显著提高(P<0.05);G1、G3和G4组肠道碱性磷酸酶(AKP)活性显著提高(P<0.05);除G1组外,其他益生菌组肠道一氧化氮(NO)含量显著增加(P<0.05)。4)与G0组相比,G1、G2和G4组肠道白细胞介素-1β(IL-1β)、白细胞介素-8(IL-8)和肿瘤坏死因子-α(TNF-α)基因相对表达量显著降低(P<0.05);G1组肠道白细胞介素-10(IL-10)基因相对表达量显著提高(P<0.05)。综上所述,在高糖饲料中添加动物双歧杆菌、鼠李糖乳杆菌和干酪乳杆菌可提高松浦镜鲤生长性能,同时提高肠道消化酶活性和抗氧化指标,以及肠道的免疫功能。

玉屏风多糖复合微生态制剂对草鱼生长和肠道菌群的影响

试验旨在探究玉屏风多糖复合微生态制剂对草鱼生长和肠道菌群的影响。选取360尾健康草鱼,随机分成3组,即基础饵料组(对照组/A组)、复合微生态制剂组(B组)、玉屏风多糖复合微生态制剂组(C组),每组3个重复,每个重复40尾鱼。试验周期为21 d。结果显示,C组草鱼末重、增重率均显著高于对照组(P<0.05)。C组草鱼肠道肌层厚度及脂肪酶活性显著高于对照组(P<0.05)。草鱼肠道菌群丰富度在试验14~21 d时明显提高,优势菌门分别为变形菌门、厚壁菌门,优势菌属为宝石杆菌属、厌氧菌属。研究表明,饵料中添加玉屏风复合微生态制剂可提高草鱼生长性能,增强肠道消化酶活性,改善肠道菌群。