Dietary Supplementation with Copper, Iron and Zinc Affects Contents of Lead and Cadmium in Tissues and Blood of Beef Cattles

本研究旨在探讨饲粮添加必需微量元素铜、铁和锌对肉牛组织和血液铅和镉含量的影响.选用20头12月龄肉牛,随机分为2组,每组10头,各组分别饲喂基础精饲料(对照组)和基础精饲料中添加铜20 mg、铁200 mg和锌200 mg的试验精饲料(试验组),粗饲料自由采食.试验期为150 d.每天以组为单位计算牛的采食量；每30 d称取牛体重并采集血液样品,试验结束后,屠宰试验牛,采集肾脏、肝脏、心脏、胰脏、脾脏、瘤胃、大肠及背肌组织样品,测定血液和组织中铅和镉含量.结果表明:牛精饲料中添加铁、铜和锌后,平均日增重极显著地提高了12.50％(P＜0.01),料重比极显著地降低了15.68％ (P ＜0.01)；铅含量在胰脏和瘤胃中极显著增加(P＜0.01),在脾脏和血液中显著减少(P＜0.05),在其余组织中无显著变化(P＞0.05),铅蓄积的器官主要是胃；镉含量在肾脏、肝脏、脾脏、瘤胃和大肠中均极显著增加(P＜0.01),但心脏中的镉含量极显著降低(P＜0.01),镉蓄积的器官主要是肾脏.结果提示,在饲粮中添加铜、铁和锌可以改善肉牛的生长性能,但不能有效减少脏器及肌肉组织中铅和镉的蓄积.     

耐镉乳酸菌对镉暴露仔鸡体重、脏器系数和组织中矿物元素含量的影响

本试验旨在探究耐镉乳酸菌对镉暴露仔鸡体重、脏器系数和组织中镉、钙、铁、锌、铜、锰、硒含量影响。选取1日龄如皋黄鸡30只,随机分为3组,每组10个重复,每个重复1只鸡。对照组试验鸡第3～6周灌喂1 mL/(d·只)无菌生理盐水;镉暴露组试验鸡第3～6周灌喂1 mL/(d·只)无菌生理盐水,并在第4～6周饮水中添加5 mg/L镉;镉+耐镉乳酸菌组试验鸡第3～6周灌喂1 mL/(d·只)耐镉乳酸菌液(1×109CFU/mL),并在第4～6周饮水中添加5 mg/L镉。预试期2周,正试期4周。结果表明:1)各组之间仔鸡体重无显著差异(P0.05)。2)镉暴露组和镉+耐镉乳酸菌组心脏系数显著低于对照组(P0.05),且镉暴露组和镉+耐镉乳酸菌组之间心脏系数无显著差异(P0.05)。3)镉暴露组的各组织中镉含量显均显著高于对照组(P0.05),且各组织中镉含量的高低依次为肾脏肝脏脾脏肺脏心脏胸肌。镉+耐镉乳酸菌组的脾脏中镉含量显著低于镉暴露组(P0.05)。4)镉+耐镉乳酸菌组肝脏中硒含量显著低于对照组和镉暴露组(P0.05)。镉+耐镉乳酸菌组和镉暴露组肾脏中硒含量显著低于对照组(P0.05)。镉暴露组肺脏中钙含量显著高于对照组和镉+耐镉乳酸菌组(P0.05),镉+耐镉乳酸菌组和镉暴露组肺脏中锌含量显著低于对照组(P0.05),镉+耐镉乳酸菌组肺脏中铜含量显著低于对照组(P0.05),镉暴露组肺脏中锰含量显著高于对照组和镉+耐镉乳酸菌组(P0.05)。镉+耐镉乳酸菌组脾脏中钙和铜含量显著低于对照组和镉暴露组(P0.05)。镉暴露组心脏中钙含量显著低于对照组(P0.05),镉+耐镉乳酸菌组和镉暴露组心脏中硒含量显著高于对照组(P0.05)。由此可见,仔鸡镉暴露时,心脏系数降低,肝脏、肾脏、肺脏、脾脏、心脏和胸肌中镉含量增加,肾脏中硒含量和心脏中钙含量降低;添加耐镉乳酸菌对镉暴露仔鸡心脏系数的降低无改善作用,但降低了脾脏和肝脏中镉含量,并增加了心脏中硒和钙含量。     

铅镉联合暴露对蛋鸡肝脏、肾脏中多种微量元素含量的影响

本研究旨在探讨Pb、Cd联合暴露对蛋鸡肝、肾组织中五种微量元素含量的影响。采用饮水对120只40周龄海兰褐蛋鸡进行铅(100 mg Pb/L)、镉(50 mg Cd/L)单独和联合(100 mg Pb/L+50 mg Cd/L)暴露8周。结果表明,铅、镉联合暴露对蛋鸡肝脏中铜、铁、锌、硒的影响呈协同效应,对锰的影响不明显;对肾脏中锰的影响呈协同效应,而对铜、铁、锌、硒呈一定的拮抗效应。铅镉在肝脏和肾脏中与微量元素之间存在复杂的相互作用。铅镉暴露引起家禽肝、肾中微量元素代谢紊乱可能是铅、镉毒性损伤的重要机制之一。     

饲粮添加铜、铁和锌对牛组织和血液铅和镉含量的影响

本研究旨在探讨饲粮添加必需微量元素铜、铁和锌对肉牛组织和血液铅和镉含量的影响。选用 ２０头 １２月龄肉牛,随机分为 ２组,每组 １０头,各组分别饲喂基础精饲料（对照组）和基础精饲料中添加铜 ２０ｍｇ、铁 ２００ｍｇ和锌 ２００ｍｇ的试验精饲料（试验组）,粗饲料自由采食。试验期为 １５０ｄ。每天以组为单位计算牛的采食量;每 ３０ｄ称取牛体重并采集血液样品,试验结束后,屠宰试验牛,采集肾脏、肝脏、心脏、胰脏、脾脏、瘤胃、大肠及背肌组织样品,测定血液和组织中铅和镉含量。结果表明：牛精饲料中添加铁、铜和锌后,平均日增重极显著地提高了１２．５０％（Ｐ＜０．０１）,料重比极显著地降低了 １５．６８％（Ｐ＜０．０１）;铅含量在胰脏和瘤胃中极显著增加（Ｐ＜０．０１）,在脾脏和血液中显著减少（Ｐ＜０．０５）,在其余组织中无显著变化（Ｐ＞０．０５）,铅蓄积的器官主要是胃;镉含量在肾脏、肝脏、脾脏、瘤胃和大肠中均极显著增加（Ｐ＜０．０１）,但心脏中的镉含量极显著降低（Ｐ＜０．０１）,镉蓄积的器官主要是肾脏。结果提示,在饲粮中添加铜、铁和锌可以改善肉牛的生长性能,但不能有效减少脏器及肌肉组织中铅和镉的蓄积。     

硒摄入对肉牛组织中镉、铅、铜、铁、锌含量的影响

本研究旨在探讨硒元素摄入对动物体内必需微量元素铜、铁、锌和有害元素铅、镉含量的影响及其机理,为降低铅、镉在食物链中的迁移和积累的控制技术提供依据。试验选用20头杂交牛,随机分为2组,每组10头,对照组饲喂基础日粮,试验组在精饲料中以预混料的形式添加亚硒酸钠1.0 mg/kg。饲养试验期为150 d,饲养试验结束后,屠宰采集各组织样品测定铅、镉、铜、铁、锌含量。结果表明:添加亚硒酸钠后对肉牛日增重影响不显著(P>0.05),但能极显著降低肉牛心脏中铅、镉的含量和血液中铅的含量(P<0.01),极显著增加胃、肾脏、肝脏等组织中铅和镉含量(P<0.01);同时也增加铜、锌、铁在胃和铜、铁在肝脏中的蓄积(P<0.05)。结果提示,在饲料中添加微量元素硒,可以改变铅、镉、铜、锌、铁在动物体内各器官和组织中的分布水平,但不能有效降低肉牛各组织中铅、镉的蓄积。     

花尾榛鸡的组织中重金属含量测定

从吉林省吉林地区,延边地区.通化地区采集花尾榛鸡样本,分别取肝脏、肾脏、肌肉3种组织.采用加热浓硝酸高氯酸消化法消化各组织样品。测定以上组织中铅、镉、镍等重金属元素的含量。检验结果:组织中铅的含量以肝脏中最高,(0.5906±0.3452)mg/kg,肾脏次之(0.4045±0.1628)mg/kg,胸肌最低(0.1121±0.0146)mg/kg,组织中镉的含量以胸肌最高(0.2595±0.0472)mg/kg,肝脏次之(0.2205±0.0852)mg/kg,肾脏中最低(0.1929±0.1386)mg/kg,组织中镍的含量以肝脏中最高(0.7653±0.1524)mg/kg,胸肌次之(0.3990±0.2413)mg/kg,肾脏最低(0.1664±0.1683)mg/kg,组织样品中肝脏中少量铅超标,肝脏、肾脏中的镉也有不同程度超标,肝脏、胸肌中镍超标。     

日粮镉和汞污染对其在蛋鸡脏器及鸡蛋中残留的影响

为研究日粮镉和汞污染对其在蛋鸡脏器与鸡蛋中残留的影响,分别选取40周龄巴布考克B300蛋鸡192只,随机分成4组,每组3个重复,每个重复16只.对照组分别饲喂玉米-豆粕型基础日粮(镉含量0.62 mg/kg,汞含量21.56 μg/kg),镉试验组日粮为基础日粮中分别添加5、10和20 mg/kg氯化镉(CdC12.2.5H2O),汞试验组日粮为基础日粮中分别添加1、3和9 mg/kg氯化汞(HgC12),试验期为9周.结果表明:各组肝脏、肾脏和卵巢中镉的含量差异均显著(P＜0.05),且随着镉添加量的升高显著升高,肾脏中各组镉含量均显著高于相同镉添加量下的肝脏和卵巢中镉含量(P＜0.05);各组蛋清和蛋黄中镉含量均随镉添加量的升高而升高,蛋清和蛋黄中镉含量均显著高于对照组(P＜0.05);汞在蛋鸡卵巢和蛋样中都有沉积,卵巢中汞沉积与日粮汞添加量呈正相关(P＜0.05);各组蛋样中汞残留量显著高于对照组,且与添加量呈正相关(P＜0.05),最高剂量组蛋样中总汞浓度达0.0544 mg/kg,超过GB2762-1994相关规定.结果提示:镉在鸡蛋中的沉积量很少,镉经机体吸收后,主要沉积在肝肾中,在卵巢中的沉积较少;汞添加量达到9 mg/kg时,蛋中汞含量超过国家标准.     

铅和镉联合染毒对雄性大鼠生殖功能的影响

将24只雄性SD大鼠(体重130±5 g)随机分成对照组、铅处理组、镉处理组和铅镉联合处理组。结果联合染毒组降低了日增重;增加了睾丸体重比、肾脏体重比,其作用介于单独作用之间,但肝脏体重比高于单独作用组。联合染毒组中血清T-SOD和谷胱甘肽过氧化物酶(GSH-Px)显著增加(P0.05)、ALT、CREA的水平显著降低(P0.05),AST、LDH、ALP的水平有所降低(P0.05)。联合作用使睾丸匀浆中TNOS、iNOS、T-SOD和丙二醛(MDA)水平显著升高(P0.05),睾丸抑制羟自由基能力显著降低(P0.05)、睾丸匀浆中GSH-Px的活力有所降低(P0.05),其作用介于单独作用之间。联合染毒组降低大鼠精子总数、顶体完整率(P0.05),但增加了畸形率(P0.05),其作用介于单组染毒组之间。铅镉联合处理组作用对大鼠生殖功能有拮抗效应。     

蜂蜜中铁铅镉相关性的研究

用原子吸收分光光度法测定蜂蜜中铁、铅、镉的质量分数 ,测定结果表明 ,铁与铅、铁与镉质量分数之间不存在相关关系     

铅、镉及铅镉联合胁迫致雏鸡红细胞膜的损伤

150只7日龄公雏鸡分为10组,分别经口灌服或在体外培养红细胞中加入生理盐水、低浓度、中浓度及高浓度的铅、镉及铅镉混合溶液,研究铅、镉及铅镉联合对雏鸡红细胞膜Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性的影响。结果表明:体内及体外红细胞铅、镉及铅镉联合染毒后,红细胞膜Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性都有不同程度的降低(P0.01或P0.05),且呈明显的时间-剂量效应关系,中浓度联合染毒组与高浓度单独染毒组差异不显著(P0.05)。铅、镉、铅镉联合均对雏鸡红细胞膜有损伤作用,铅镉对红细胞膜的损伤有协同作用。     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Scrapie in goats in Cyprus

Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).