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1.
虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响 总被引：1，自引：0，他引：1
分别在基础饲料(对照组)中添加100 mg/kg的虾青素、角黄素,混合色素(50 mg/kg虾青素+50 mg/kg角黄素)饲喂初始体重为(56.60±0.63) g的虹鳟60 d,考察虾青素和角黄素对虹鳟肌肉着色和肝脏总抗氧化能力的影响。结果显示,饲料中添加了虾青素、角黄素和混合色素后对虹鳟增重率、饲料系数及肌肉常规成分、肌肉失水率、含肉率均无显著影响(P> 0.05)。虾青素组、角黄素组和混合色素组虹鳟肌肉的比色卡得分、红度、虾青素含量和血清总类胡萝卜素含量均比对照组有显著提高(P< 0.05);虾青素组虹鳟肌肉比色卡得分(26.25)和红度值(18.40)显著高于角黄素组(22.38, 14.13)和混合色素组(24.00, 15.70)(P< 0.05);虾青素组虹鳟肌肉虾青素含量为4.75 mg/kg (30 d)和6.45 mg/kg (60 d),均显著高于混合色素组的3.87 mg/kg (30 d)和5.48 mg/kg (60 d)(P< 0.05);在虹鳟血清总类胡萝卜素含量方面,虾青素组 > 混合色素组 > 角黄素组;虾青素组、角黄素组、混合色素组虹鳟肝脏的总抗氧化能力之间无显著差异(P> 0.05),分别为2.39 U/mg,2.25 U/mg,2.39 U/mg,均较对照组(2.03 U/mg)显著提高(P< 0.05)。上述结果表明：饲料中添加100 mg/kg虾青素、角黄素及虾青素+角黄素混合(1∶1)均能有效改善虹鳟肌肉颜色,提高肝脏总抗氧化能力,虾青素、虾青素+角黄素混合(1∶1)对虹鳟肌肉的着色效果优于角黄素。 相似文献
2.
猪饲料中添加高剂量铜、锌对粗脂肪及粗蛋白质消化率的影响 总被引：3，自引：0，他引：3
分铜、锌进行了2个消化试验,分别选择20kg左右的健康长×荣去势猪只24头,随机分为4组,每组6个重复,每个重复1头,消化代谢笼单圈饲养。测定了猪饲料中添加高剂量铜(100mg/kg、200mg/kg、300mg/kg、400mg/kg)、锌(100mg/kg、250mg/kg、500mg/kg、3000mg/kg)对粗脂肪及粗蛋白质消化率的影响。结果表明,饲料中添加高剂量铜、锌能提高猪对粗脂肪及粗蛋白质的消化率。含铜200mg/kg组粗脂肪消化率最高,极显著地高于100mg/kg组(P<0.01),300mg/kg组及400mg/kg组显著地高于100mg/kg组(P<0.05),铜对粗蛋白质消化率的影响也表现出含铜200mg/kg组最高,显著地高于100mg/kg组(P<0.05);含锌250mg/kg组及3000mg/kg组粗脂肪的消化率均极显著地高于100mg/kg组(P<0.01),500mg/kg组显著地高于100mg/kg组(P<0.05),而3个高锌组之间差异不显著(P>0.05),饲料中添加高剂量锌对粗蛋白质消化率也有不同程度提高,但均未达显著性水准(P>0.05)。 相似文献
3.
选用体重为16.85±0.68g的湘云鲫180尾,随机分为三组,每组两个重复,每个重复30尾鱼.采用单因子实验设计,在基础日粮中添加0mg/kg(对照组)、500mg/kg、1000mg/kg免疫多糖,经45d的生长试验研究免疫多糖对湘云鲫生长和消化酶活性的影响.结果表明:500mg/kg免疫多糖组对湘云鲫的生长,肠道和肝胰脏的各消化酶活性影响均不显著(P>0.05),而1000mg/kg免疫多糖组能显著促进湘云鲫生长和提高蛋白酶活性(P<0.05),但对淀粉酶和脂肪酶活性影响不显著(P>0.05). 相似文献
4.
5.
黄芪多糖对仿刺参非特异性免疫功能的影响 总被引：5，自引：0，他引：5
向刺参体腔中注射相同体积(500 μl)的无菌黄芪多糖溶液后第1、3、6 d,测定体腔液中溶菌酶、超氧化物歧化酶、碱性磷酸酶活性及补体C3的含量,研究黄芪多糖对刺参免疫系统的影响.每头刺参多糖含量分别达0.2、0.4、0.6 mg,溶菌酶、超氧化物歧化酶、碱性磷酸酶活性及补体C3含量均在注射后第3 d达到最高,且前3种指标以0.6 mg/头剂量组最高,分别达到232.25 U/ml,45.1 U/ml,966.5 nkat/L;C3含量则以0.4 mg/头剂量效果最好,达到0.09 g/L.经SPSS软件分析,均与对照组差异显著(P<0.05),表明黄芪多糖具有增强刺参免疫功能的作用. 相似文献
6.
饲料锌添加水平对凡纳滨对虾免疫抗菌机能和溶菌酶mRNA及Toll受体mRNA表达的影响 总被引：4，自引：4，他引：0
在基础饲料中添加不同水平蛋氨酸锌(添加水平分别为0、50、150 mg Zn/kg)并饲喂凡纳滨对虾,养殖14 d后,取样测定对虾鳃组织中Toll受体mRNA和溶菌酶mRNA的表达水平以及肝胰腺、肌肉和血淋巴中超氧化物歧化酶(SOD)和溶菌酶(LSZ)活性,并进行溶藻弧菌人工急性感染试验。结果表明,凡纳滨对虾肝胰腺及肌肉中锌蓄积水平随饲料锌添加量的增加而显著增加(P<0.05),肝胰腺中锌蓄积更明显。添加50 mg Zn/kg组(锌含量为73.25 mg Zn/kg饲料)对虾鳃组织中的Toll受体mRNA和溶菌酶mRNA表达量均显著高于未添加锌组和添加150 mg Zn/kg组(P<0.05)。添加50 mg Zn/kg组对虾肌肉、肝胰腺和血淋巴中溶菌酶活性显著高于未添加锌组(P<0.05)。添加50 mg Zn/kg组对虾肝胰腺和血淋巴中的SOD活性也显著高于未添加锌组,但与添加150 mg Zn/kg组无显著差异。而肌肉中SOD活性在添加150 mg Zn/kg组中最高。经溶藻弧菌人工急性感染后,添加50 mg Zn/kg组对虾半致死时间和全致死时间大于未添加锌组和添加150 mg Zn/kg组。本研究表明,相比摄食未添加锌组饲料和添加150 mg Zn/kg组饲料,凡纳滨对虾的免疫抗菌机能在摄取添加50 mg Zn/kg(锌含量为73.25 mg Zn/kg饲料)饲料时得到改善。 相似文献
7.
灰树花多糖对鲫鱼免疫功能的影响 总被引：6，自引：0，他引：6
以灰树花多糖（Polysaccharide of Grifola frondosa，PGF）药饵连续投喂鲫鱼35d，通过测定血清凝集抗体效价、超氧化物歧化酶（Superoxide dismutase，SOD）活性、离体白细胞吞噬活性（phagocytic activity）、吞噬细胞杀菌活性（bactericidal activity），研究灰树花多糖对水产动物特别是鲫鱼免疫功能的影响。试验设计以不同剂量（分别为250mg／kg鱼体重、400mg／kg鱼体重、500mg／kg鱼体重、600mg／kg鱼体重、1000mg／kg鱼体重）的灰树花多糖药饵饲喂试验鲫鱼，分别于第0、7、14、2l、28、35d用血凝板法、MTT染色法进行免疫学指标测定。结果表明，各添加水平均可增强鲫鱼的免疫功能，其中剂量为400mg／kg、500mg／kg和600mg／kg的吞噬活性及杀菌活性与对照组相比存在极显著性差异（P〈0．01），而剂量为250mg／kg、1000mg／kg时，杀菌活性均与对照组相比存在显著性差异（P〈0．05）；400mg／kg组、500mg／kg和600mg／kg组的SOD活性与对照组相比存在极显著性差异（P〈0．01）；400mg／kg组、500mg／kg和600mg／kg组的血清凝集抗体效价最高为1：256，250mg／kg和1000mg／kg组的血清凝集抗体效价最高为1：32。各项指标的峰值出现在第2～3周。 相似文献
8.
不同抗生素药物组合在断奶仔猪的应用效果 总被引：1，自引：0，他引：1
为了研究不同抗生素药物组合在断奶仔猪的应用效果,本试验选用8kg左右“杜×长×大”三元杂交断奶仔猪108头,分3个组,每个组设3个重复,每个重复12头。分别在基础日粮中添加了3种不同抗生素组合的药物添加剂。预试期4d,正试期35d。结果表明,30mg/kg阿美拉霉素+10mg/kg硫酸粘杆菌素的日增重最高,比30mg/kg吉它霉素+10mg/kg硫酸粘杆菌素组提高1.44%(P>0.05),比50mg/kg杆菌肽锌+10mg/kg硫酸粘杆菌素组提高9.15%(P<0.05);而料肉比30mg/kg阿美拉霉素+10mg/kg硫酸粘杆菌素组与30mg/kg吉它霉素+10mg/kg硫酸粘杆菌素组一致,均比50mg/kg杆菌肽锌+10mg/kg硫酸粘杆菌素组提高3.3%(P>0.05). 相似文献
9.
在基础饲料中添加不同剂量(1%、3%、5%)的微胶囊剂型黄芪多糖(Astragalus polysac-charudes,APS)(载药量为17%),制成3种配合饲料,连续投喂初始体重为22.0±1.0g的刺参Apostichopus japonicus35d,探讨微胶囊剂型黄芪多糖(以下简称"微胶囊")对刺参生长性能、非特异性免疫及抗病力的影响。结果显示,35d后刺参最高特定生长率(Specific growth rate,SGR)为0.51%/d(5%添加组)(P<0.05);微胶囊添加量为3%时免疫效果最佳,刺参体腔液中酸性磷酸酶ACP、超氧化物歧化酶SOD、髓过氧化物酶MPO活性显著高于对照组(P<0.05)。试验期间每隔7d测定刺参体腔液样品,其中ACP活性在第28天最高,为11.2U/100ml(P<0.05);SOD活性在第21天最高,为63.3U/ml(P<0.05);MPO活性在第21天最高,为40MPO单位/ml(P>0.05);免疫试验结束后对刺参进行灿烂弧菌Vibrio splendidus攻毒实验,14d内观察得出,3%微胶囊添加组累积死亡率明显低于对照组(P<0.05)。由此可得,微胶囊剂型黄芪多糖对仿刺参生长性能、免疫力及抗病力方面均具有显著的增强效果,以3%添加量效果最佳,且添加量、作用时间、免疫效果之间存在相关性。 相似文献
10.
在15±0.5℃条件下,向初始体质量为(21.00±2.00)g的仿刺参(Apostichopus japonicas Selenka)体内注射400μL(质量浓度为1.2 mg·mL-1)几种免疫增强剂(黄芪多糖、枸杞多糖、黄柏提取物、苦参提取物、党参提取物、菊粉、天蚕素、神曲提取物、山楂提取物),第1、3、5d时测定仿刺参肠道消化酶活性,第5d时制作前肠组织切片,研究不同免疫增强剂对仿刺参肠道消化酶活性及组织结构的影响。结果表明,在注射免疫增强剂后第3d,菊粉组仿刺参肠道蛋白酶活性最高,达15.16μg·g-1·min-1,与对照组7.07μg·g-1·min-1差异显著(P<0.05),而黄柏提取物抑制了蛋白酶活性;神曲组淀粉酶活性达72.57 U·dl-1,与对照组(53.2 U·dl-1)差异显著(P<0.05);菊粉和山楂提取物对仿刺参肠道纤维素酶活性影响显著(P<0.05),其他处理组与对照比较无明显变化(P>0.05);黄芪多糖组褐藻酸酶活性最高,达2.06μg·g-1·min-1,其次是菊粉组。在养殖试验期间淀粉酶比活力变化趋势较稳定,纤维素酶次之,褐藻酸酶和蛋白酶变化幅度较大。各种免疫增强剂对仿刺参肠道组织结构的影响不同,黄柏、苦参提取物损伤了组织结构,而黄芪多糖、菊粉等促进了细胞分泌。 相似文献
11.
通过喷涂和预处理两种方法将不同浓度植酸酶添加到豆粕型金鳟(Oncorhynchus mykissW albaum)饲料中,研究了植酸酶对金鳟粪磷及养殖水环境中磷含量的影响。金鳟粪磷分析结果显示,喷涂法添加植酸酶,对照组中粪磷含量最高,其他各试验组较对照组差异显著(P<0.05),但500~2000 U/kg组中粪磷含量差异显著(P<0.05),2500~6000 U/kg组中粪磷含量无显著差异(P(0.05);预处理法添加植酸酶,对照组粪磷含量最高,其他各试验组粪磷含量较对照组降低显著(P<0.05),但添加植酸酶的各试验组之间差异不显著(P(0.05)。通过水中磷含量试分析结果显示,无论是喷涂法添加植酸酶还是预处理法添加植酸酶,各试验组水体总磷含量分别较其对照组差异不显著(P(0.05),各试验组的活性磷含量均未检出。实验结果表明,金鳟饲料中添加植酸酶可以降低粪磷含量,对养殖生产过程中控制磷的排放,减少磷污染具有重要的意义。 相似文献
12.
Influence of vitamin C on the immune system of salmonids 总被引：3，自引：0，他引：3
Abstract. Trials were run to determine the immunomodulatory effect of dietary vitamin C in rainbow trout. Oncorhynchus mykiss (Walbaum), and Atlanticsalmon, Salmo Salar L. We first investigated whether depletion of ascorbic acid (AA) could depress the immune system. Subsequently, we focused our studies on the stimulatory effect of a high dietary dose of stable vitamin C derivatives (1000mg AA-equivalent per kg of feed) in order to determine their prophylactic role. Three trials were run with rainbow trout fed, for periods of time varying from 2 to 6 months, a high dietary dose of ascorbate-2-polyphosphate (AAPP) or L-ascorbate-2-monophosphate calcium salt (AAMP) equivalent to 1000mg AA per kg of feed. The high dietary level of vitamin C was compared to 60mg AA-equivalent per kg of feed. Another experiment was conducted with Atlantic salmon pre-fed AAPP at 60mg/kg for 6 months followed by AAPP at 1000mg/kg for 2 months. Various immune parameters were tested such as mitogen-induced proliferation, serum complement level, phagocytosis and natural cytotoxicity. Leucocyte and plasma AA contents were also determined. The immune response in vitamin-C deficient trout was not strongly different from that in trout fed the minimal growth requirement level. Serum complement level was not affected by vitamin C. A high dietary dose of vitamin C was found to increase trout and salmon leucocyte AA content, mitogen-induced proliferation of lymphocytes, and chemiluminescence response of leucocytes with a higher constancy, when the cells were stimulated with opsonized zymosan and with luminol as a substrate. Natural cytotoxicity was enhanced in trout fed a high dietary dose of vitamin C. The results of these immunity studies support supplementation levels of vitamin C which are much higher than the minimal requirement known to prevent deficiency symptoms and promote normal growth. Further investigations on the time-dose response are needed to define quantitatively the high dietary dose of vitamin C. 相似文献
13.
Effects of E/Z Isomers and Coating Materials of Astaxanthin Products on the Pigmentation and Antioxidation of Rainbow Trout,Oncorhynchus mykiss 
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下载免费PDF全文 Xinxin Zhao Jing Hu Xiaoqing Zhang Xiaoqin Li Xiangjun Leng Shilin Wu Dong Cheng 《Journal of the World Aquaculture Society》2016,47(3):341-351
The objective of this study was to compare the effects of four astaxanthin preparations with different ratio of E/Z (trans/cis) isomers and different coating materials on the pigmentation and antioxidation properties of rainbow trout. Five diets were designed as basal diet (without astaxanthin supplementation) and four astaxanthin diets (100 mg/kg diet) supplemented with four astaxanthin products, BASF (79% all‐E, gelatin coated), Wisdom‐B (85% all‐E, gelatin coated), Wisdom‐C (94% all‐E, carrageenan coated), and Wisdom‐D (94% all‐E, gelatin coated). After 4 wk feeding, the flesh astaxanthin content, redness, and yellowness of astaxanthin‐supplemented groups were higher than those of control group at the second and fourth week (P < 0.05). Among these astaxanthin‐supplemented groups, the Wisdom‐B group had the highest flesh redness and astaxanthin content. The astaxanthin‐supplemented groups also had the lower flesh frozen loss and malondialdehyde level than control group at the fourth week (P < 0.05). The results indicated that dietary 100 mg/kg astaxanthin could improve the flesh redness and antioxidation abilities of rainbow trout. The ration of E/Z isomers and properties of coating materials of astaxanthin preparations influenced the pigmentation and antioxidation properties, and Wisdom‐B had a better pigmentation effect on the flesh than other astaxanthin preparations. 相似文献
14.
ABSTRACTThe objective of the current study was to determine the effects of chitosan (CH) coatings containing Mentha spicata essential oil (MSO; 0.2 and 0.4%) and zinc oxide nanoparticle (ZnO; 0.2 and 0.4%) on chemical (total volatile basic nitrogen (TVB-N), 2-thiobarbituric acid reactive substances (TBARS) and peroxide value (PV)), microbial (total viable count, psychrotrophic count, Pseudomonas spp., and Enterobacteriaceae) and sensory (odor, color, and overall acceptability) properties of raw rainbow trout fillets during 14 days of refrigerated storage. Final microbial population of CH + MSO 0.4% + ZnO 0.4% and CH + MSO 0.4% + ZnO 0.2% retarded approximately 3–5 log CFU/g as compared to control groups (P < 0.05). At the end of storage time in control samples, TVB-N, TBARS, and PV reached 49.3 mg N/100 g, 3.31 mg malonaldehyde/kg, and 2.04 meq peroxide/kg lipid, while the values for the treated samples with MSO (0.2 and 0.4%) in combination with ZnO (0.2 and 0.4%) remained lower than 25 mg N/100 g, 2 mg malonaldehyde/kg, and 1.1 meq peroxide/kg lipid, respectively. The results indicate a potential use of CH coating containing MSO and ZnO as an effective type of antimicrobial packaging to maintain quality of rainbow trout fillets. 相似文献
15.
Abstract. L-ascorbate-2-polyphosphate (brand name: ROVIMIX STAY-C) is a vitamin C derivative which is highly stable during feed processing and storage. Trials were run to determine the biological efficacy of L-ascorbate-2-polyphosphate (AAPP) in comparison to a coated ascorbic acid form (AASC).
Bioavailability was studied by force-feeding rainbow trout, Oncorhynchus mykiss (Wal- baum), a single dose of both ascorbate forms and evaluating the kinetics of plasma ascorbic acid (AA).
Growth performance and tissue concentrations of ascorbic acid in liver, anterior kidney and plasma were compared in rainbow trout (initial body weight: 9g) fed a practical diet containing AAPP at 60, 200 or 1000 mg AA equivalent/kg feed. Two other groups were fed either no vitamin C or AASC at 200 mg/kg. Liver AA contents were monitored after 0, 10, 20, 30, 60 and 157 days of experimental feeding, while head kidney and plasma AA contents were measured at day 157.
Atlantic salmon of the start-feeding stage received a practical diet containing AAPP at 0,60 or 200 mg A A equivalent/kg. AAPP was compared to AASC at the equimolar dose of 200mg/kg. Liver AA contents were measured after 14, 47, 124 and 205 days of feeding. Head kidney and plasma AA levels were also analysed at the end of the trial.
Results showed that AAPP and AASC were equally bioavailable, thus suggesting that ascorbate-2-polyphosphate is absorbed in the blood as free ascorbic acid. In both Atlantic salmon, Salmo salar L., and rainbow trout, liver AA levels reflected well the dietary dose of ascorbate. At the 200mg/kg dose, ROVIMIX STAY-C supported higher vitamin C hepatic levels than did coated ascorbic acid. 相似文献
Bioavailability was studied by force-feeding rainbow trout, Oncorhynchus mykiss (Wal- baum), a single dose of both ascorbate forms and evaluating the kinetics of plasma ascorbic acid (AA).
Growth performance and tissue concentrations of ascorbic acid in liver, anterior kidney and plasma were compared in rainbow trout (initial body weight: 9g) fed a practical diet containing AAPP at 60, 200 or 1000 mg AA equivalent/kg feed. Two other groups were fed either no vitamin C or AASC at 200 mg/kg. Liver AA contents were monitored after 0, 10, 20, 30, 60 and 157 days of experimental feeding, while head kidney and plasma AA contents were measured at day 157.
Atlantic salmon of the start-feeding stage received a practical diet containing AAPP at 0,60 or 200 mg A A equivalent/kg. AAPP was compared to AASC at the equimolar dose of 200mg/kg. Liver AA contents were measured after 14, 47, 124 and 205 days of feeding. Head kidney and plasma AA levels were also analysed at the end of the trial.
Results showed that AAPP and AASC were equally bioavailable, thus suggesting that ascorbate-2-polyphosphate is absorbed in the blood as free ascorbic acid. In both Atlantic salmon, Salmo salar L., and rainbow trout, liver AA levels reflected well the dietary dose of ascorbate. At the 200mg/kg dose, ROVIMIX STAY-C supported higher vitamin C hepatic levels than did coated ascorbic acid. 相似文献
16.
Richard Skøtt Rasmussen Flemming Hausgaard Larsen Stig Jensen 《Aquaculture International》2007,15(2):97-107
Rainbow trout were studied at different rearing densities, fish sizes and feeding frequencies so that we could evaluate the
effect of these parameters on fin condition, growth and feed utilisation. In one study, two sizes of rainbow trout (18–70 g
or 48–125 g), fed to near satiation at 17.7°C, were examined at two rearing densities (11–41 kg m−3 or 21–92 kg m−3). This study showed that the anal fin was healthier (P < 0.05) at low densities. In the second study rainbow trout were again fed to near satiation and grown from 50 g to 125 g
in 16.4°C water, and they were fed either once daily or three times daily at two densities (18–45 kg m−3 or 54–124 kg m−3). Rainbow trout growth and feed utilisation were slightly but significantly (P < 0.05) reduced at high densities, while dorsal fin condition, surprisingly, was better (P < 0.0001) at the high densities. Possible explanations to these findings are discussed. Condition of the left pectoral fin
was improved at once daily feeding (P < 0.05) compared with three feedings per day, at which fights for feed possibly are more frequent. 相似文献
17.
Igor I. Solar Edward M. Donaldson George A. Hunter 《Aquaculture (Amsterdam, Netherlands)》1984,42(2):129-139
The oral administration of 17α-methyltestosterone (MT) to wild rainbow trout fry at concentrations ranging from 1 to 100 mg/kg diet for periods up to 120 days following swim-up produced male-female ratios substantially different from controls. 100% males were produced with low MT doses (1, 3 and 9 mg/kg diet) administered for 60 days. High proportions (79–90%) of sterile rainbow trout were obtained with greater doses of the steroid (25, 50 and 100 mg/kg diet) fed for 120 days. A paradoxical feminizing effect at high doses of MT (50 and 100 mg/kg diet) was observed irrespective of the length of the treatment. No dose-related mortality during the treatments was observed. 相似文献
18.
Peracetic acid (PAA) is an effective disinfectant/sanitizer for certain industrial applications. PAA has been described as a powerful oxidant capable of producing water quality benefits comparable to those expected with ozone application; however, the water oxidizing capacity of PAA in aquaculture systems and its effects on fish production require further investigation, particularly within recirculation aquaculture systems (RAS). To this end, a trial was conducted using six replicated RAS; three operated with semi-continuous PAA dosing and three without PAA addition, while culturing rainbow trout Oncorhynchus mykiss. Three target PAA doses (0.05, 0.10, and 0.30 mg/L) were evaluated at approximately monthly intervals. A water recycle rate >99% was maintained and system hydraulic retention time averaged 2.7 days. Rainbow trout performance metrics including growth, survival, and feed conversion ratio were not affected by PAA dosing. Water quality was unaffected by PAA for most tested parameters. Oxidative reduction potential increased directly with PAA dose and was greater (P < 0.05) in RAS where PAA was added, indicating the potential for ORP to monitor PAA residuals. True color was lower (P < 0.05) in RAS with target PAA concentrations of 0.10 and 0.30 mg/L. Off-flavor (geosmin and 2-methylisoborneol) levels in culture water, biofilm, and trout fillets were not affected by PAA dosing under the conditions of this study. Overall, semi-continuous PAA dosing from 0.05-0.30 mg/L was compatible with rainbow trout performance and RAS operation, but did not create water quality improvements like those expected when applying low-dose ozone. 相似文献
19.
Viviane Verlhac‐Trichet Jouni Vielma Jorge Dias Paulo Rema Ester Santigosa Thomas Wahli Kurt Vogel 《Journal of the World Aquaculture Society》2014,45(4):367-379
The efficacy and tolerance of a novel microbial 6‐phytase were investigated in rainbow trout, Oncorhynchus mykiss, and Nile tilapia, Oreochromis niloticus. Reference diets were sufficient in available phosphorus (P). The test diet limiting in available P was supplemented with phytase at 500, 1000, or 2000 phytase units/kg feed. The enzyme was effective in increasing total P apparent digestibility coefficient in relation to increasing the dose of phytase in rainbow trout and Nile tilapia. Zinc apparent digestibility improved in relation to phytase supplementation in rainbow trout. P release due to phytase supplementation ranged from 0.06 to 0.18% P/kg feed in rainbow trout and from 0.13 to 0.26% P/kg feed in Nile tilapia. A 58‐d performance trial was conducted to evaluate tolerance of fish to phytase supplementation. Dietary treatments consisted of a basal diet without phytase or supplemented with 2000 and 200,000 phytase units/kg feed. Results indicate that this novel microbial 6‐phytase is well tolerated by fish. Significant improvements for growth as well as feed conversion ratio were observed when the phytase was fed at 2000 phytase units/kg feed. This phytase is proven efficient in releasing P from phytate and could be added when plants are used for fish meal replacement in diets for salmonid and omnivorous fish. 相似文献