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为研究壳聚糖对水环境镉致罗非鱼急性毒性-半致死时间(LT(50))的影响,将200尾罗非鱼随机分为2个处理组,每处理4个重复,每重复25尾鱼.对照组和试验组水中镉的质量浓度为20 mg/L,试验组添加0.1 g/L的壳聚糖.结果表明:除了第8小时外,第16、第24、第32、第40和第48小时对照组的病死率均显著低于试验组;对照组LT(50)为(24.39±3.58)h,试验组LT(50)为(39.1±5.8)h,2个处理组间差异极显著.这说明,壳聚糖可一定程度上缓解镉对罗非鱼的急性毒性. 相似文献
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研究壳聚糖对水环境锌致罗非鱼急性毒性的影响,将540尾罗非鱼随机分为2个处理组,即对照组和试验组.每处理组分3个重复,每重复90尾鱼.对照组按照水生生物急性毒性试验方法进行锌对罗非鱼的急性毒性试验；试验组养殖水体中加入壳聚糖,同法进行锌对罗非鱼的急性毒性试验.结果表明:对照组48 h的半致死质量浓度(LC50)为(18.39±1.68) mg/L,试验组为(26.65±2.84) mg/L,差异显著；对照组96 h的LC50为(9.34±0.94) mg/L,试验组为(13.53±0.81) mg/L,差异显著.说明养殖水体中加入壳聚糖具有缓解锌致罗非鱼急性毒性的作用. 相似文献
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《饲料工业》2015,(20)
采用单因子随机区组试验设计方法,以平均体重为(10.69±0.55)g的吉富罗非鱼幼鱼为试验对象,在镉水平为50 mg/kg的吉富罗非鱼饲料中添加0.5%、1.0%和1.5%的壳聚糖饲喂7周,研究壳聚糖减轻饲料镉对吉富罗非鱼亚慢性毒性的效果。结果显示:与未添加壳聚糖组相比,添加壳聚糖可显著提高饲料镉胁迫下吉富罗非鱼的增重率和特定生长率(P0.05),且随着饲料中壳聚糖水平的增加逐渐升高;肠道消化酶的活性随着饲料中壳聚糖水平的增加而升高,1.5%壳聚糖添加组淀粉酶活性、1.0%壳聚糖添加组和1.5%壳聚糖添加组的脂肪酶活性以及各壳聚糖添加组的蛋白酶活性均显著升高(P0.05);降低了血液尿素氮、谷丙转氨酶和谷草转氨酶水平;随着壳聚糖的添加水平升高,肠道、肌肉和养殖水体中镉水平显著降低(P0.05),粪便镉水平显著升高(P0.05)。试验结果表明,壳聚糖对饲料镉致罗非鱼亚慢性毒性的缓解效果随其在饲料中添加水平的升高而增强,并在很大程度上通过发挥吸附作用减轻了饲料镉对罗非鱼的毒性。 相似文献
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壳聚糖对草鱼生长、抗病性能的影响 总被引：8，自引：0，他引：8
以初始体重为(1.04±0.01)g的草鱼为研究对象,在基础饲料中分别添加0%(对照组)、0.25%、0.50%、0.75%、1.00%的壳聚糖制成5种试验饲料,在室内控温、24h充气的循环水族箱中进行为期70d的生长试验,测定试验鱼的生长率和对嗜水气单胞菌的抗感染能力。结果表明,壳聚糖对草鱼的生长、对嗜水气单胞菌的抗感染能力有显著的影响(P<0.05);试验鱼的生长率、抗病能力随着壳聚糖添加量的增加呈先升高后降低的趋势,0.50%和0.75%壳聚糖组相对增重率最大、对嗜水气单胞菌的抗感染能力最强,与对照组相比差异显著,但两组之间无显著差异。 相似文献
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本试验采用急性毒性试验、污染物致突变性检测(Ames试验)、小鼠骨髓细胞微核试验和小鼠精子畸形试验对槲皮素作为饲料添加剂的安全性进行评价。结果表明:槲皮素半数致死剂量(LD50)>10 g/kg BW;Ames试验鼠伤寒沙门菌突变型各菌株在加与不加肝微粒体多氯联苯诱导剂(S9)情况下,经过2次试验结果均呈阴性;小鼠骨髓细胞微核试验结果为阴性,各槲皮素剂量组动物未见细胞毒性作用;小鼠精子畸形试验结果表明槲皮素剂量组与阴性对照组相比差异均不显著(P>0.05),且没有剂量反应关系。试验结果提示,槲皮素是一种安全的饲料添加剂。 相似文献
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采用动物毒性试验方法,对强普生Ⅲ号进行了毒性、安全性评价。结果显示:小鼠的急性毒性反应和死亡率与给药剂量成正比,强普生Ⅲ号的半数致死量(LD50)为44.20±2.96 mL/kg,LD50的95%可信限为47.26~41.35 mL/kg,表现为无急性毒性。亚慢性毒性试验,实验期间小鼠的临床表现、体质量变化、饲料消耗量、血常规检查、血清生化检查等各项指标,试验组与对照组均无显著差异,各组脏器剖检和病理学切片检查也均无病理学变化。吸入毒性试验,试验组鸡整体状况正常,72 h内无中毒反应和死亡,血清生化指标值均在正常范围内,与对照组无显著差异。 相似文献
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小鼠镉的蓄积性毒性试验研究 总被引：2，自引：0，他引：2
选用SPF级昆明种小鼠140只,做急性毒性和蓄积性毒性试验。通过急性毒性试验,得出Cd LD50为94.1 mg/kg体重。蓄积性毒性试验中,试验组小鼠每日灌胃染毒1次,Ⅰ组,1/10 LD50（Cd 9.41 mg/kg体重）;Ⅱ组,1/5 LD50（Cd 18.82 mg/kg体重）;Ⅲ组,1/3 LD50（Cd 31.36 mg/kg体重）;对照组Cd为 0 mg/kg体重,试验期4周。结果显示,染镉组小鼠生长发育落后于对照组（P<0.05或P<0.01）,组织镉残留量高于对照组（P<0.05或P<0.01）,肝细胞和肾小管上皮细胞变性,脾脏瘀血,并有明显的剂量—效应关系。 相似文献
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《黑龙江畜牧兽医》2017,(15)
为了确定硼砂对鲫鱼的毒性大小,试验采用静水生物试验法,通过设置5个不同浓度组,连续观察96 h,根据急性毒性试验结果分别计算出硼砂对鲫鱼的24,48,72,96小时时的半致死浓度(LC_(50))分别为2 250.78 mg/L,1 652.04 mg/L,1 445.98 mg/L,1 341.26 mg/L。根据公式计算得出硼砂对鲫鱼的安全浓度(SC)为134.126 mg/L,根据《化学农药环境安全评价试验准则》中农药对鱼类的毒性等级划分标准,判定硼砂对鲫鱼的毒性级别为低毒;鲫鱼分别在0、安全浓度、1/3倍的96小时时半致死浓度(1/3 96 h LC_(50))、2/3倍的96小时时半致死浓度(2/3 96 h LC_(50))药物浓度下经过72 h染毒后,制作肠道切片进行观察。结果表明:安全浓度组与对照组相比,对照组鲫鱼肠道绒毛排列整齐,褶皱高度较高,安全浓度组鲫鱼绒毛高度与对照组相比没有明显差别,但部分绒毛出现断裂。1/396 h LC_(50)组与对照组相比,1/3 96 h LC_(50)组鲫鱼肠道绒毛出现糜烂状,没有清晰的轮廓。2/3 96 h LC_(50)组与对照组相比,鲫鱼肠道绒毛出现萎缩状。 相似文献
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1. Two experiments were conducted to investigate the effects of dietary chitosan on growth performance, energy availability and protein retention in broilers. 2. Experiment 1 was a 42-d growth assay, in which 294 1-d-old male broilers were given one of 7 dietary treatments. A control feed was supplemented with 5 levels of chitosan (0.2, 0.5, 1.0, 3.0 and 5.0 g/kg) or 50 mg/kg chlortetracycline (CTC). 3. Increasing chitosan inclusion gave a nonlinear increase (P< 0.001) in feed conversion efficiency (FCE). Optimal growth and feed conversion were obtained with 0.5-1.0 g/kg chitosan. 4. In experiment 2, 42 1-d-old male broilers (6/treatment) were individually housed but fed on the same diets as in experiment 1. Excreta were collected from d 19-21 and d 40-42. 5. The addition of 0.5-1.0 g/kg chitosan increased nitrogen retention compared with the control group (P< 0.01), while apparent metabolisable energy in the diets was not altered. 相似文献
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本试验旨在研究饲粮中添加不同水平壳聚糖对14~70日龄扬州鹅生长性能、屠宰性能、脏器指数及血清生化指标的影响,以确定鹅饲粮中壳聚糖适宜添加水平。选取360只14日龄健康、体重相近的扬州鹅公鹅,随机分为5个组,每组6个重复,每个重复12只鹅。对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮中添加250、500、1 000和2 000 mg/kg壳聚糖的试验饲粮。试验期56 d。结果表明,与对照组相比:1)饲粮添加500 mg/kg壳聚糖显著提高了42、56和70日龄鹅体重及14~70日龄平均日采食量、平均日增重(P0.05),显著降低了14~70日龄料重比(P0.05)。2)饲粮添加250、500、1 000和2 000 mg/kg壳聚糖显著降低了鹅腹脂率(P0.05)。3)饲粮添加500 mg/kg壳聚糖显著提高了鹅心脏指数、肝脏指数、脾脏指数、空肠指数、回肠指数和盲肠指数(P0.05)。4)饲粮添加500 mg/kg壳聚糖显著提高了鹅血清球蛋白、葡萄糖含量(P0.05),显著降低了血清碱性磷酸酶活性(P0.05);饲粮添加250、500、1 000 mg/kg壳聚糖显著降低了血清中甘油三酯、总胆固醇含量(P0.05)。由此可知,饲粮中添加壳聚糖可以改善扬州鹅生长性能,对其屠宰性能、脏器指数和血清生化指标有一定影响。在生产实践中,扬州鹅饲粮中壳聚糖添加500 mg/kg效果最佳。 相似文献
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壳聚糖对肉仔鸡生长性能及免疫功能的影响 总被引：25，自引：1，他引：25
试验选择 1日龄AA雄性肉仔鸡 2 94只 ,随机分为 7个日粮处理组 ,每个处理 6个重复 ,每个重复 7只鸡 ,进行为期 4 2d的生长试验。结果表明 :添加 0 .0 2 %～ 0 .30 %壳聚糖均表现出一定的促生长作用 ,尤以添加 0 .0 5 %时促生长作用最明显 ,其效果优于金霉素 ;而当添加量达到 0 .5 0 %时 ,未表现出促生长效果。从免疫指标看 ,高剂量的壳聚糖 (0 .5 0 % )可显著提高肉仔鸡的抗体滴度 ,吞噬指数以 0 .0 5 %～ 0 .30 %壳聚糖组较高 ,淋巴细胞转化率以0 .10 %～ 0 .5 0 %壳聚糖组较高。试验表明 ,壳聚糖对肉仔鸡生长和免疫的影响与添加剂量有关。添加 0 .0 5 %时 ,可明显提高肉仔鸡的生长性能 ;而添加更高水平时 ,虽免疫功能有所增强 ,但生长性能却有下降趋势。因此 ,0 .0 5 %可看作壳聚糖的适宜添加量。 相似文献
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本试验采用单因子试验设计,选用100只健康1日龄天山雪鹅,随机分为5组,以研究日粮中添加不同水平的壳聚糖（0、100、200、300、400 g/t）对天山雪鹅生长性能及免疫器官的影响。结果表明,添加不同水平壳聚糖对天山雪鹅平均日增重（average daily gain, ADG）的影响差异均不显著（P＞0.05）;添加300 g/t水平的壳聚糖料重比最低,可显著提高饲料利用率;试验组与对照组血清总蛋白与血清白蛋白水平差异显著（P＜0.05）,对血清球蛋白水平与对免疫器官的影响及盲肠内大肠杆菌的影响差异不显著（P＞0.05）。 相似文献
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Previous studies have indicated that reducing dietary CP may improve N utilization and effectively diminish manure ammonia emissions; however, the response of manure odor emissions to such dietary modifications has been inconsistent. The objective of the current experiment was to induce decreased lactobacilli (DL) numbers in the distal gastrointestinal tract (dGIT; cecum + colon) of finishing pigs offered both high- and low-CP diets through consumption of chitosan, and examine the influence of this model on manure ammonia and odor emissions when compared with a positive control diet. It was hypothesized that an DL population would be accompanied by an increase in markers of protein fermentation. When compared with normal lactobacilli populations in the dGIT, generation of an DL population would result in increased manure odor emissions from pigs offered both dietary CP concentrations. A 2 × 2 factorial arrangement of treatments was conducted to investigate the effect of including chitosan [0 (positive control) vs. 20 g/kg of feed] and high or low dietary CP concentration (200 vs. 150 g/kg of feed) on nutrient digestibility, N utilization, selected bacterial populations, and metabolite composition of the dGIT and manure emissions from finisher pigs (60.3 kg). Consumption of chitosan had no influence (P > 0.05) on nutrient digestibility or N utilization. In both high- and low-CP diets, consumption of chitosan decreased the lactobacilli-to-Enterobacteriaceae ratio (P < 0.01), generating an DL population, and increased pH (P < 0.01) in the dGIT and ammonia (P = 0.02) in the cecum compared with diets that supported normal lactobacilli populations. Consumption of chitosan decreased molar proportions of butyric acid (P < 0.01) and increased valeric acid (P < 0.01) in the dGIT compared with unsupplemented diets. Furthermore, consumption of chitosan increased manure odor emissions (P = 0.05) compared with unsupplemented diets. There was no effect (P > 0.05) of chitosan consumption on manure ammonia emissions from 0 to 240 h. The current study demonstrates that dietary chitosan suppressed populations of lactobacilli in the dGIT. In response, a considerable increase in Enterobacteriaceae, markers of protein fermentation, and manure odor emissions was observed compared with the positive control diet. These effects were observed in pigs offered both high-and low-CP diets. The current study indicates a possible role for lactic-acid bacteria in modulating manure odor emissions relatively independent of the proportions of dietary CP available for fermentation in the dGIT. 相似文献
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试验选用1日龄AA雄性肉仔鸡270只,随机分到5个日粮处理组,进行为期42d的饲养试验。5种日粮是在基础日粮中加入0、50、100、150mg/kg的壳聚糖和50mg/kg的金霉素。结果表明:日粮中添加100mg/kg壳聚糖在提高日增重趋势的同时,提高了饲料转化效率,效果优于金霉素。在血清生化指标方面,100mg/kg壳聚糖组相比对照组降低了血清中TC、TG含量(P<0.05),提高了TPI、GF-1和GH含量(P<0.05),而对葡萄糖和尿酸含量无影响(P>0.05)。初步确定壳聚糖在肉鸡日粮中的适宜添加量为100mg/kg。壳聚糖的促生长作用可能与提高了血清中GH和IGF-1的分泌有关。 相似文献
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多糖复合物对鲫鱼生长性能的影响 总被引：1，自引：1，他引：0
通过在日粮中添加不同水平多糖复合物(MCS),研究其对鲫鱼(CarassiusauratusL.)生长性能的影响。试验选用640条体重约为0.90g的鲫鱼,随机分为4组(对照组、0.25%、0.50%MCS组和1.00%MCS组)。试验期为8周。研究结果表明,添加0.25%和0.50%MCS可以显著提高试验鲫鱼终末均重、增重率和特定生长率(P0.05);添加0.25%、0.50%和1.00%MCS,试验鲫鱼蛋白质利用效率显著提高(P0.05);饵料系数有不同程度的降低,但差异不显著(P0.05);存活率差异不显著(P0.05)。表明在饲料中添加一定量的多糖复合物,对水产动物生长性能具有明显的促进作用,且以0.25%效果较佳。 相似文献
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Effects of dietary chitosan on fat deposition and lipase activity in digesta in broiler chickens 总被引：12，自引：0，他引：12
1. The effect of dietary chitosan on fat deposition and lipase activity in the small intestinal contents was investigated in broiler chickens fed an adequate or high metabolisable energy (ME) diet. 2. Male broiler chickens at 14 d old were fed on the adequate or high ME diet supplemented with 0 or 50 g/kg chitosan, which has a low viscosity, for 3 weeks. 3. Dietary chitosan did not affect food intake, body weight gain or food efficiency in either dietary ME groups. 4. Dietary chitosan reduced the excessive abdominal fat deposition induced by the high ME diet. 5. Dietary chitosan increased the weight of intestinal contents irrespective of dietary ME concentration. 6. Dietary chitosan decreased the lipase activity per g of small intestinal contents. 7. These results suggest that dietary chitosan with low viscosity decreases lipase activity and fat absorption in the small intestine, consequently resulting in a reduction of fat deposition in broiler chickens. 8. It was concluded that dietary chitosan with low viscosity can decrease body fat deposition without reducing food intake and body weight gain in broiler chickens. 相似文献
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X.‐Y. Han W.‐L. Du C.‐L. Fan Z.‐R. Xu 《Journal of animal physiology and animal nutrition》2010,94(5):e138-e144
The study was conducted to investigate the effect of copper‐loaded chitosan nanoparticles on the composition and metabolism of the caecal microbiota in rats. Forty male Sprague–Dawley (SD) rats (average body weight of 82 ± 5 g) were randomly assigned to five groups (n = 8). The dietary treatments were: (i) basal diet, (ii) basal diet + 80 mg/kg BW CuSO4, (iii) basal diet + 80 mg/kg BW chitosan (CS‐I), (iv) basal diet + 80 mg/kg BW copper‐loaded chitosan nanoparticles (CSN‐I) and (v) basal diet + 160 mg/kg BW copper‐loaded chitosan nanoparticles (CSN‐II). The trial lasted 21 days. The results showed that compared with control, Average day gain (ADG) of group CSN‐I and CSN‐II increased (p < 0.05). No significant difference was found in CuSO4 or CS‐I‐treated groups (p > 0.05). There were no effects of these treatments on average day feed intake (ADFI) of rats (p > 0.05). The counts of Bifidobacteria and Lactobacillus in group CSN‐II were higher than those of the control group (p < 0.05), while the counts of total aerobes, total anaerobes, Salmonella, Clostridium and coliform were lower than those of the control (p < 0.05). The activity of β‐glucuronidase in group CSN‐I or CSN‐II was significantly depressed (p < 0.05), while the activities of α‐galactosidase and β‐galactosidase were enhanced significantly (p < 0.05). The pH of the caecum digesta and the concentration of propionate and butyrate in group CSN‐I and CSN‐II were higher than those of the control group (p < 0.05). No significant difference was found in these parameters in CuSO4 or CS‐I‐treated groups (p > 0.05). The results indicate that the microbiota and environment of caecum are beneficially changed by the administration of copper‐loaded CSN. 相似文献