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1.
The use of prebiotics and probiotics as feed supplements that improve efficiency of intestinal bacteria is becoming de rigueur in animal husbandry in many regions worldwide. We tested the effects of a commercial probiotic (Biogen®) containing allicin, high unit hydrolytic enzyme, Bacillus subtilis spores and ginseng extracts on survival, growth, carcass composition and feed cost/benefit in rabbitfish Siganus rivulatus. Fifteen net cages (100 × 100 × 40 cm; L × W × H) were stocked with 10 juvenile rabbitfish (10.3 g per fish) each and placed in a large rectangular tank and offered feed at 4% body weight daily. Cages were offered one of five isonitrogenous and isocaloric diets containing 0, 1, 2, 3 and 4 g kg−1 probiotic at three replicates per treatment for 98 days. Fish in all cages were weighed at 2‐week intervals and feed regimen was adjusted accordingly. Rabbitfish offered the control diet exhibited lower growth and feed utilization than all experimental treatments. There was no effect of probiotic inclusion level on survival but growth was better at all inclusion levels than in the control. No significant differences (P > 0.05) in growth were observed among fish groups fed various levels of the probiotic. Carcass composition was not affected by dietary probiotic inclusion. Ultimately, when all variables are considered, Biogen® inclusion to diets appears to reduce feed cost per unit growth of rabbitfish. 相似文献
2.
Rabbitfish are an Indo‐Pacific herbivorous marine fish that have good market demand and are suitable for aquaculture. The present work was performed to determine dietary protein inclusion necessary for optimal growth of juvenile rabbitfish Siganus rivulatus. Six diets with increasing levels of protein (10, 20, 30, 40, 50 and 60 g crude protein 100 g?1 feed) and similar levels of gross energy (20 MJ kg?1) were prepared and offered to S. rivulatus juveniles maintained in triplicate cages placed in two large water tanks for 49 days. Growth progressively improved with dietary protein for fish offered diets from 10% to 40% protein inclusion. Diets with greater protein levels did not improve fish growth beyond that observed in the 40% group. Daily feed intake, apparent protein utilization and feed conversion ratio decreased as dietary protein increased. Protein efficiency (PE) was greatest (1.47) in fish offered the 10% protein diet and least in fish offered the 60% protein diet (0.80). No differences in PE were observed among all other treatments (20–50%). Results of the present work suggest that minimum dietary requirement for suitable growth of S. rivulatus juveniles is 40% protein when digestible energy of the diet is 16–18 MJ kg?1. 相似文献
3.
The present work was performed to assess whether soybean meal (SBM) could replace fish meal (FM) as a source of dietary protein in diets of the marine herbivore Siganus rivulatus. Five iso-nitrogenous (40% protein) and iso-energetic (14 MJ/Kg) diets were prepared with SBM replacing fish meal at 0%, 25%, 50%, 75%, and 100% dietary protein. A 60-day feeding trial was conducted with 240 juvenile S. rivulatus (initial body mass 1.74 ± 0.03 g). Survival, growth, feed, and protein efficiency and hematological parameters were assessed. Growth correlated negatively with increase in dietary SBM. All production parameters measured were negatively affected at all levels of SBM inclusion. There were no effects on total or differential blood counts, hemoglobin, or plasma protein, but hematocrit values were negatively correlated with SBM addition. Results suggest that total replacement of FM by SBM without adding other supplements is not recommended, even for an herbivorous marine fish such as S. rivulatus. 相似文献
4.
以cfb基因保守序列的6个区域设计4条特异性引物,利用链置换DNA聚合酶( BstDNA polymer：ase)在恒温(65℃)下保温40 min,建立了无乳链球菌 Streptococcus agalactiae 的 LAMP 技术。建立的LAMP方法能够特异性地检测无乳链球菌,检测灵敏度为3·7×101~3·7×102 cfu/mL,反应前加入显色剂钙黄绿素避免二次污染。现场应用中采用FTA卡采集红尾皇冠鱼Aequidens rivulatus病鱼肝脏组织病原菌,操作简便、快捷。研究表明,针对无乳链球菌cfb基因建立的LAMP检测方法具有较高的特异性及稳定性,尤其是具有快速、简便、成本低等优点,可用于无乳链球菌的野外现场快速检测。 相似文献
5.
A. BARAKAT R. ROUMIEH N.E. ABDEL MEGUID J. GHANAWI I. PATRICK SAOUD 《Aquaculture Nutrition》2011,17(3):e773-e780
The present work was designed to evaluate the effects of various feeding regimens on rabbitfish growth and condition. Twelve juvenile rabbitfish Siganus rivulatus (7.3 ± 0.1 g) were stocked into each of 15 tanks. Tanks were randomly assigned one of five treatments with three replicate tanks per treatment. Treatments were G‐I: fish fed once daily at 08.00; G‐II: fish fed once daily at 17.00; G‐III: fish fed twice daily at 08.00, 17.00; G‐IV: fish fed three times daily, at 08.00, 13.00, 17.00; G‐V: fish fed three times daily at 08.00, 13.00, 17.00 for six consecutive days, followed by 1 day of fasting. Fish were offered a commercial diet (Golden Extruded, 450 g kg?1 protein, 200 g kg?1 lipids) to apparent satiation. At the conclusion of the study, weight gain of rabbitfish fed three times daily (273.1%) was significantly greater than weight gain of fish in all other treatments. Feed conversion ratio (FCR) of fish fed once per day (1.5) was significantly greater than FCR in all other treatments. Proportion of lipids in fish fed three times per day was significantly greater than in fish from other treatments. Ultrastructure of muscle of fish offered feed three times daily had a better organized appearance and better defined striation than muscle of fish in other treatments. Accordingly, feeding rabbitfish three times daily is better than feeding them once or twice daily and also improves muscle ultrastructure and quality. 相似文献
6.
为了解速大肥和高稳胺对皇冠鱼生长及抗氧化能力的影响,以皇冠鱼(Aequidens rivulatus)为试验对象,在其基础饲料中添加0.5%的速大肥和高稳胺,进行对照试验,投喂30 d后测定其生长情况及肝脏过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、丙二醛(MDA)的含量。结果表明,0.5%速大肥添加量对皇冠鱼的生长起促进作用,降低了饲料系数,增强了机体抗氧化能力。高稳胺对皇冠鱼的抗氧化能力有显著作用。投喂高稳胺饲料后机体SOD活性与MDA含量均有所提高,其对皇冠鱼的生长起增益效果。因此,速大肥和高稳胺可用作皇冠鱼饲料添加剂大幅提高皇冠鱼产量。 相似文献
7.
Hamidreza Ahmadniaye Motlagh Mehrdad Sarkheil Omid Safari Marina Paolucci 《Aquaculture Research》2020,51(1):197-205
The present study was designed to investigate the effects of dietary apple cider vinegar (ACV) on digestive enzyme activity and growth performance as well as immune responses and antibacterial activity of skin mucus in green terror (Andinoacara rivulatus). Fish were fed diets supplemented with 0%, 1%, 2% and 4% of ACV (40.830 ppm acetic acid concentration) for 63 days. The final weight and weight gain values were observed to be significantly higher in fish fed with 2% of ACV compared to the control group (p < .05). ACV inclusion in the diets had significant effects on SGR (%) and FCR values (p > .05). ACV treatment resulted in a significant increase in the intestinal protease, α‐amylase, lipase and alkaline phosphatase activities compared to control (p < .05). The activities of digestive enzymes in fish fed with 2% and 4% of ACV diets were significantly higher than the other groups (p < .05). The total protein content, alternative haemolytic complement, alkaline phosphatase, total immunoglobulins and lysozyme activities of skin mucus increased significantly in fish fed with ACV diets (p < .05). In conclusion, administration of ACV enhanced digestive enzyme activity, growth performance, immune responses and the immune properties of skin mucus, and it can be used as a natural growth promoter and immunostimulant in green terror culture. 相似文献
8.
Interest in culturing marbled spinefoot rabbitfish Siganus rivulatus is increasing in countries on the Eastern Mediterranean, Red Sea and Arabian Gulf. However, information on environmental tolerances and requirements for optimal growth are scarce. In the present work, the temperature requirements for spinefoot rabbitfish were investigated in two experiments. In the first experiment, juvenile rabbitfish were distributed into eight 180 L square tanks at 12 fish per tank. The temperature in four tanks was reduced at a rate of 1 °C day?1 and in four tanks was increased by 1 °C day?1 until the fish stopped feeding. Minimum and maximum temperatures for feeding were recorded. In the second experiment, the fish were placed in four temperature treatments (17, 22, 27, 32 °C) at four replicates per treatment for 8 weeks. Survival and growth were evaluated. Fish stopped feeding at 14 and 36 °C. Their maximum growth rate was at 27 °C, and survival was 100% in all treatments. The relationship between specific growth rate and temperature was parabolic, described by the equation: SGR=?0.0014 (T3)+0.0798 (T2)?1.3089 (T)+6.7342. The results show that S. rivulatus is a eurythermal fish whose optimal temperature for growth is circa 27 °C. 相似文献
9.
[目的]了解表面活性剂对蓝点笛鲷幼鱼的毒性。[方法]采用半静水法生物测试,以蓝点笛鲷幼鱼为受试生物,研究了十二烷基硫酸钠（SDS）、十二烷基苯磺酸钠（DBS）对其急性毒性,[结果]2种表面活性剂的毒性大小为：SDS〉DBS。其安全浓度分别为0.406 3、0.584 0 mg/L。SDS与DBS对蓝点笛鲷幼鱼的24和48 h的LC50分别为2.022 0、2.858 5 mg/L和1.769 1、2.514 9 mg/L。[结论]SDS与DBS对蓝点笛鲷幼鱼为中等毒性物质。 相似文献
10.
4种水产药物对蓝点笛鲷幼鱼急性毒性试验 总被引：3，自引：0，他引：3
采用半静水法生物测试,以蓝点笛鲷（Lutjanus rivulatus）幼鱼为受试生物,研究了甲醛、苯扎溴铵、聚维酮碘和高效氯氰菊酯对其的急性毒性。结果表明,毒性大小依次为高效氯氰菊酯〉聚维酮碘〉苯扎溴钱〉甲醛。甲醛、苯扎溴铵和聚维酮碘为低毒物质,安全质量浓度（SC）分别为19．8800mg·L^-1、7．5710mg·L^-1和2．8429mg·L^-1;高效氯氰菊酯为剧毒物质,SC为0．0028mg·L^-1;甲醛、苯扎溴铵、聚维酮碘和高效氯氰菊酯对蓝点笛鲷幼鱼的24h半数致死质量浓度（LC50）分别为81．3240mg·L^-1、40．7619mg·L^-1、15．2077mg·L^-1和0．0153mg·L^-1;48hL C50分别为75．9587mg·L^-1、34．7413mg·L^-1、12．9894mg·L^-1和0．0129mg·L^-1。根据试验结果,建议菊酯类不宜作为蓝点笛鲷育苗药物使用,聚维酮碘和苯扎溴铵要慎用。 相似文献