硒对STZ诱发糖尿病大鼠骨密度影响的研究初报

比较了在低硒饲料的基础上补充不同形态硒对糖尿病大鼠骨密度的影响。健康SD大鼠 1 2 8只 ,体重 50～ 60 g,随机分为 4组 ,每组 32只 ,雌雄各半 ,其中Ⅰ组为低硒对照组 (饲料含硒量 0 0 37mg/kg) ;Ⅱ组为补充亚硒酸钠组 (饲料含硒量 0 3mg/kg) ;Ⅲ组为补充富硒麦芽组(饲料含硒量 0 3mg/kg) ;Ⅳ组为补充富硒酵母组 (饲料含硒量 0 3mg/kg)。Ⅱ、Ⅲ、Ⅳ组的饲料均是在Ⅰ组低硒饲料的基础上分别添加适量的亚硒酸钠、富硒麦芽、富硒酵母后配制而成。喂饲 5周后 ,Ⅰ、Ⅱ、Ⅲ、Ⅳ组用链脲佐菌素 (streptozotocin ,STZ)按 60mg/kg腹腔注射诱发糖尿病 ,继续饲喂 6周。用单光子吸收法测定各组大鼠的肱骨、股骨、胫骨、桡骨的骨密度。结果表明 :①STZ致糖尿病大鼠的骨密度随时间的延长有逐渐下降的趋势。Ⅱ、Ⅲ、Ⅳ补硒组大鼠可以在一定时间内延缓STZ致糖尿病大鼠的骨密度下降。在此期间骨密度的下降以肱骨出现最早 ,股骨次之 ,桡骨、胫骨再次之。②饲料补硒组糖尿病大鼠的肱骨、股骨中硒的含量较饲料低硒组糖尿病大鼠的肱骨、股骨中硒的含量显著提高。③补充硒的形态 ,即有机硒 (富硒麦芽、富硒酵母 )或无机硒 (亚硒酸钠 )对糖尿病大鼠肱骨、股骨、胫骨、桡骨的骨密度影响差异不显著。     

富硒麦芽对实验性肝癌大鼠NO、NOS和脂质过氧化的影响

50只清洁级sD大鼠随机分为4组：对照组（5只）、模型组（15只）、富硒麦芽组（15只）和亚硒酸钠组（15只）。对照组和模型组饲喂大鼠基础饲料，饲料含硒量为0．1mg／kg；富硒麦芽组和亚硒酸钠组分别在基础饲料中补充富硒麦芽和亚硒酸钠，饲料含硒量为3．0mg／kg。除对照组外，其余3组采用0．01％二乙基亚硝胺（DEN）诱发大鼠肝癌16周，停止诱癌后继续饲养2周再处死全部大鼠，观察富硒麦芽对丙氨酸氨基转移酶（ALT）、碱性磷酸酶（ALP）、白蛋白（ALB）、总胆红素（TBIL）、一氧化氮（NO）、一氧化氮合成酶（NOS）、丙二醛（MDA）和谷胱甘肽过氧化物酶（GSH—Px）的影响。结果显示，富硒麦芽组大鼠血浆ALT、ALP、TBII—NO、MDA和肝组织NO、NOs、MDA显著低于模型组，全血和肝组织GSH—Px活性显著高于模型组；与亚硒酸钠组相比，富硒麦芽组大鼠血浆和肝组织的NO含量和NOS活性显著降低。试验表明富硒麦芽具有减轻肝脏损伤、延缓大鼠肝癌形成的能力，其作用机制之一可能为富硒麦芽能抑制NO的产生，清除体内大量过剩的氧自由基。减轻NO等自由基所致的脂质过氧化损伤。     

富硒麦芽硒在鸡蛋中的分布及蛋鸡对其相对生物利用率

采用短期饲喂试验研究了富硒麦芽硒在鸡蛋中的沉积以及蛋鸡对其相对生物利用率。将30羽70周龄，产蛋率60%的伊莎蛋鸡随机均分为3组，A组为对照组，饲以基础日粮(含硒0.23mg/kg)；B、C组为试验组，B组饲以基础日粮加亚硒酸钠，日粮含硒(0.70±0.03)mg/kg,C组饲以基础日粮加富硒麦芽，日粮含硒(0.72±0.02)mg/kg。试验过程中观察蛋鸡的生产性能，定期从各组鸡所产蛋中随机抽取5枚测定蛋清、蛋黄硒含量，计算总硒量。试验结束时，每组鸡全部扑杀，测定其全血、肝、肾硒含量和GSH-Px的活性。结果显示，日粮中加硒可提高鸡蛋、肝、肾硒含量和全血、肝、肾GSH-Px活性，但对蛋鸡生产性能无显著影响；与亚硒酸钠一样，饲喂富硒麦芽鸡所产蛋中的硒主要存在于蛋黄中；以亚硒酸钠的相对生物利用率为100%计，富硒麦芽硒提高肝、肾硒含量和GSH-Px活性的相对生物利用率分别为86.4%、98%、116%、111%。     

硒缺乏病

硒是家禽所必需的微量元素之一.它的生理功能及在体内的代谢过程等问题正越来越引起家禽营养学家和病理学家们的重视.现已知道,家禽缺硒时就会出现一种称之为渗出性素质的病症.在植物性饲料中,硒的含量与土壤含硒量有很大的关系.种植在缺硒土壤中的作物,含硒量比较低.在常用饲料中,鱼粉的含硒量较高,但利用率却比较低.一般来说,动物性饲料中的硒,其利用率低于25%,     

添加天然含硒矿物质饲料对产蛋鸡的影响

选２８周龄罗曼蛋鸡用单因子试验设计，添加不同水平硒的天然矿物质饲料，结果表明：硒可被蛋鸡吸收利用，沉积于鸡蛋和组织器官，并生产出富硒鸡蛋；当天然矿物质饲料中含硒２５ｍｇ／ｋｇ，饲粮中添加１０％时，可提高产蛋率８％、产蛋量１８％、耗料量降低１５％，饲料成本降低０．５２元，鸡蛋中硒含量达０．４０ｍｇ／ｋｇ，试鸡心脏，肾脏，肝脏和肌肉均未见病理异常。     

改进饲料使鸡产含鱼油成分的蛋

改进饲料使鸡产含鱼油成分的蛋美国得克萨斯州Ａ＆Ｍ大学的家禽专家，通过改进饲料，使产蛋鸡产下了含鱼油成分的鸡蛋。这种含鱼油成分的新品种鸡蛋，内含通常在鱼油中才能发现的ω—３脂肪酸和维生素Ｅ。这两种营养素，均有助于预防心脏病等心血管疾病。为使鸡能产含鱼油...     

酵母硒对鸡蛋硒含量的影响

为了研究酵母硒对鸡蛋硒含量的影响,试验选择30周龄京白蛋鸡3,500只,随机分为5组,每组700只,设1个对照组和4个试验组。对照组饲料中硒的含量为0.3mg/kg,以亚硒酸钠形式添加。试验组以福邦酵母硒替代亚硒酸钠,饲料中硒的含量为试验A组0.3mg/kg、试验B组0.4mg/kg、试验C组0.5mg/kg、试验D组0.6mg/kg,试验期4周。结果表明,对照组鸡蛋硒含量为0.285mg/kg,试验组鸡蛋硒含量在0.333~0.492mg/kg之间。因此,在蛋鸡饲料中添加酵母硒生产富硒鸡蛋,其添加量以0.3~0.4mg/kg最佳,饲喂1周后即可达到富硒鸡蛋的要求。     

富硒鸡蛋的研究现状

硒是每日必须摄入的膳食营养素之一，富硒鸡蛋是目前世界上最好的硒营养补充剂。本文综述了近年来国内外学者对富硒鸡蛋的研究现状，包括富硒鸡蛋中的含硒量、蛋品质的研究；蛋鸡养殖中富硒日粮影响其繁殖性能、产蛋率、蛋鸡肉品质等生产性能的研究；不同种类的富硒饲料的饲喂剂量、饲喂方式及蛋中的富硒效果等研究，为生产安全、优质的富硒鸡蛋提供保证。     

硒在畜牧生产中的开发与应用

微量元素种类很多，但一般指硒、钴、碲、镉、钒、锌等元素，其中硒是家畜家禽的一种必需营养素。硒是150多年前瑞典化学家柏齐力阿斯发现的。经多方研究证明，它是谷胱甘肽过氧化酶的成分，维生素E是一种抗氧化剂，两者共同作用可预防过氧化酶伤害细胞，并参与畜禽新陈代谢的作用。很多饲料都含有硒元素，但玉米和小麦含硒量最高。     

不同形式硒对大鼠生长及短期肝癌模型发生的影响

SD大鼠75只，体重50～60g，随机均分5组。组Ⅰ，正常对照组；组Ⅱ，试验对照组；组Ⅲ，高亚硒酸钠组；组Ⅳ，富硒麦芽组；组Ⅴ，富硒酵母组。组Ⅰ、Ⅱ、Ⅲ各组基础饲料中分别添加亚硒酸钠硒，含量分别为0．1、0．1、0．3mg／kg；组Ⅳ，基础饲料中添加富硒麦芽硒0．3mg／kg；组Ⅴ，基础饲料中添加富硒酵母硒0．3mg／kg。各组饲喂基础料第32天时，除组Ⅰ大鼠外，其余4组大鼠实施“AFB1致肝癌短期实验模型程序”。记录各组大鼠体重情况，测定血清碱性磷酸酶（ALP）、甲胎蛋白（AFP）、NO和γ-谷氨酰转移酶（γ-GTase）、SOD、MDA含量，以及肝、肾组织和全血中谷胱甘肽过氧化物酶（GSH—Px）、MDA、SOD、羟脯氨酸（HyP）的活性。结果：与对照组相比，富硒酵母硒和富硒麦芽硒能显著促进大鼠生长，提高大鼠增重率、降低料肉比，而亚硒酸钠硒作用不明显；并明显降低血清γ-GTase、HyP水平，提升全血GSH—Px活性及血清SOD水平，有效清除肾脏MDA；在降低血清ALP、AFP和快速提高全血GSH—Px活性方面，富硒麦芽硒作用优于富硒酵母硒。表明富硒酵母硒和富硒麦芽硒比亚硒酸钠硒能更有效提高大鼠生长速度，增强其抗氧化能力，从而抵抗AFB1所致肝肿瘤。     

Relationship between selenium content of forage, blood and organs of sheep, and lamb mortality rate

The investigation comprised 12 herds, totalling 660 sheep, in the counties of Stockholm and Uppsala. The selenium content of specimens of forage, whole blood, muscle, liver, and kidney was determined by a fluorimetric method. Data on the number of born and dead lambs were collected 4—5 months after lambing. Dead and sick lambs were subjected to necropsy and to clinico-chemical analyses, respectively.The selenium content of hay and corn was lower than 60 ng per g, which some authors regard as the minimum level of Se requirement for protection against white muscle disease in sheep. The analyses of forage mixtures containing oil concentrates and beet pulp showed selenium levels that were about 2—5 times as high as this minimum level.In herds in which the animals had not been treated with selenium preparations prior to sampling, there was a significant positive correlation between the selenium content of the forage and that of whole blood. A relationship was also noted between the selenium content of forage and of organs.In 9 out of the 12 herds the selenium concentrations in whole blood were on the level that is considered to be representative of white muscle disease.A high mortality rate was recorded for lambs whose mothers had low selenium levels in their blood.Prophylactic and curative treatment with selenium plus vitamin E orally and/or parenterally probably reduced lamb mortality rate in the herds fed a low-selenium diet.     

内蒙古河套灌区小麦地复栽紫花苜蓿试验

小麦是内蒙古河套灌区主要的粮食作物,在7月下旬收获后,还有约2个月的作物生长期,为充分利用这段时间的光热资源,进行了小麦茬地复栽紫花苜蓿Medicago sative的试验研究.试验证明,对紫花苜蓿提前育苗,适时移栽,可起到粮草双收的增产效果,经济效益和生态效益远高于传统复种的蔓菁Brassica rapa.     

普氏原羚自然栖息地草地矿物质营养的评价

矿物质元素是动物生长发育和生命活动必需的营养。为了更好地开展普氏原羚的保护工作,对普氏原羚主要栖息地的青海湖布哈河上游地区高寒草甸的矿物质营养分布特点进行了系统的分析。应用显微分析法分析动物食性,采取电感耦合等离子体原子发射光谱法分析矿物质含量。结果发现,牧草萌发期的混合牧草硒和铜元素含量极显著高于牧草快速生长期(Cu,F_2,27=3.27, P=0.008; Se,F_2,27=3.27, P=0.009),但牧草枯黄期与萌发期间无显著差异。不同牧草品种体内的矿物质元素含量也存在明显的差异,唐古特铁线莲、沙蒿、芨芨草是主要的高硒植物,其中芨芨草硒含量最高。芨芨草是普氏原羚的基本食物,占总食物的13.68%,但不是普氏原羚的喜食植物(选择性指数为-0.886)。碱蒿、冷蒿、紫花针茅是主要的高铜植物,其中紫花针茅的铜含量最高,是普氏原羚的主要食物,占总食物的9.40%,但不是普氏原羚的喜食植物(选择性指数为0.037)。因此,对放牧动物来说,普氏原羚栖息地存在严重的矿物质营养不平衡问题,属于严重硒缺乏区,季节性铜硒缺乏区,普氏原羚基本食物是高硒植物芨芨草,增加了其食物的平均硒含量,普氏原羚的主要食物是含铜量最高的紫花针茅,增加了其食物的平均铜含量。增加牧场高硒和高铜植物的比例,提高土壤牧草的硒和铜元素的含量和扩大普氏原羚的采食范围都是保护普氏原羚的主要措施。     

Wheat pasture bloat dynamics, in vitro ruminal gas production, and potential bloat mitigation with condensed tannins

The aim of this study was to determine the effect of winter wheat (Triticum aestivum L.) forage growth stage, forage allowance, time of day, and commercial condensed tannins (CT) on steer bloat dynamics and in vitro ruminal gas production. Twenty-six crossbreed steers (Angus x Hereford x Salers; average initial BW = 194 +/- 26 kg) were used. Wheat forage allowances were either 18 kg (high forage allowance) and 6 kg (low forage allowance) of DM/(100 kg BW.d). In each bloat observation period, fresh wheat forage samples were hand-clipped to ground level in all study pastures for nutrient and in vitro ruminal gas production analyses. In vitro ruminal gas accumulation was measured at 0, 1, 2, 3, 4, 5, 6, and 12 h. Commercial CT was added at 0, 10, 15, and 20 mg of CT/g of DM. Bloat was scored once per week on two consecutive days at 0800 and 1500 during the vegetative stage and once every 2 wk during the reproductive stage of wheat development. Mean bloat score was calculated for each steer by time of day, stage of plant growth, and forage allowance. Bloat was detected in 65.8% of the observation periods. Average bloat scores were four and 2.5 times greater (P < 0.05) in cattle grazing at a high forage allowance than at a low forage allowance in the vegetative and reproductive growth phases of wheat, respectively. Rate of gas production was greater (P < 0.001) in the vegetative stage than in the reproductive stage. Steer bloat score was positively correlated with forage CP (r = 0.22; P < 0.05) and IVDMD (r = 0.32; P < 0.05). Rate of ruminal gas production was positively correlated (P < 0.01) to forage CP (r = 0.48), NPN (r = 0.40), soluble protein (r = 0.32), and IVDMD (r = 0.47). Conversely, negative correlations were found for forage DM (r = -0.20; P < 0.05), insoluble protein (r = -0.40), NDF (r = -0.69), and forage height (r = -0.49; P < 0.01) on the rate of ruminal gas production. Addition of CT at levels greater than 10 mg of CT/g of DM decreased (P < 0.05) the rate of in vitro ruminal gas and methane gas production after 5 h of incubation. Wheat pasture bloat is a complex disorder that varies across an array of forage and environmental conditions. Condensed tannins have the potential to decrease bloat by altering ruminal gas production and soluble protein digestibility from wheat forage.     

内蒙古四子王旗草原土壤—牧草—放牧绵羊生态系统微量元素的季节变化研究与盈亏分析

[目的]对内蒙古四子王旗荒漠草原土壤—牧草—放牧绵羊生态系统中的微量元素含量进行分析,研究不同季节放牧绵羊体内矿物质元素的盈亏状况,评定矿物质元素营养限制因子。[方法]选取6只体况良好的体重为（39.65±2.25）kg的放牧蒙古羊母羊作为试验羊,测定该地区牧草嫩草期（6月）、生长期（9月）和枯草期（11月）放牧绵羊的体重、采食量、排粪量和排尿量;检测牧草3个生长时期草原土壤、牧草以及放牧绵羊血清中的7种矿物质元素（铁、铜、锰、锌、硒、钼、钴）含量;借助采食量模型预测放牧绵羊在牧草不同生长时期的矿物质元素摄入量;利用代谢试验测定从粪、尿中排出的矿物质元素含量,计算放牧绵羊体内矿物质元素沉积量。[结果]放牧绵羊的体重和采食量在牧草3个生长时期之间差异均极显著（P<0.01）,枯草期排粪量极显著（P<0.01）高于嫩草期和生长期。草原土壤、牧草及绵羊血清中的铁元素含量在牧草不同生长时期之间差异均不显著（P>0.05）,铁元素含量均不存在缺乏情况。枯草期牧草的铜元素含量极显著（P<0.01）低于嫩草期和生长期,枯草期绵羊体内沉积的铜元素含量极显著（P<0.01）低于生长期,并出现了负沉积。草原土壤、牧草以及绵羊采食和体内沉积的锰、钼元素含量在牧草不同生长时期之间存在极显著（P<0.01）差异,但两种元素不存在缺乏情况。嫩草期绵羊血清中的锌元素含量显著（P<0.05）高于生长期和枯草期;草原土壤、牧草、绵羊体内沉积的锌元素含量在牧草不同生长时期之间虽无显著（P>0.05）差异,但存在缺锌的情况。草原土壤中的硒元素含量在牧草生长期最高,极显著（P<0.01）高于嫩草期和枯草期,嫩草期和生长期牧草中的硒元素含量低于正常水平下限,而枯草期牧草中未检测到硒元素;绵羊血清中硒元素的含量在牧草不同生长时期之间差异不显著（P>0.05）,但均处于正常水平的下限。草原土壤中的钴元素含量在牧草不同生长时期之间差异不显著（P>0.05）,但均低于标准值;枯草期和嫩草期绵羊体内沉积的钴元素含量极显著（P<0.01）低于生长期。[结论]建议在该地区全年以适当形式为放牧绵羊补锌和硒元素,冬季或春季可适当补饲含铜和钴的微量元素制剂。     

高寒草甸环境硒缺乏对牦牛血液生化指标及抗氧化系统功能的影响

为探究牦牛以骨骼肌损伤为特征的疾病的发病原因及诊断和治疗方案,本试验采用电感耦合等离子体原子发射光谱法分析土壤、牧草和动物组织矿物质元素含量,应用全自动血细胞分析仪、生化分析仪及可见光分光光度法分析血液参数、生化指标和抗氧化指标。结果显示,疾病发生区土壤和牧草硒含量均极显著低于正常区域(P<0.01);患病牦牛血液、肝脏和毛发硒含量均极显著低于健康牦牛(P<0.01)。患病牦牛血红蛋白(Hb)、红细胞数(RBC)极显著低于健康牦牛(P<0.01),血清磷酸肌酸激酶(CPK)、谷丙转氨酶(GPT)、天门冬氨酸氨基转移酶(GOT)、碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)均极显著高于健康牦牛(P<0.01);患病牦牛血清超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性及游离三碘甲腺原氨酸(FT_3)和三碘甲腺原氨酸(T_3)含量均极显著低于健康牦牛(P<0.01),血清丙二醛(MDA)、游离甲状腺素(FT_4)、甲状腺素(T_4)和促甲状腺激素(TSH)含量均极显著高于健康牦牛(P<0.01)。通过注射0.1%亚硒酸钠和5%维生素E的复方灭菌溶液对患病牦牛进行治疗,治疗组牦牛血液硒含量和血清抗氧化指标逐渐恢复正常,临床症状消失。因此,推测牦牛以骨骼肌损伤为特征的疾病是土壤和牧草硒缺乏所引起,以上结果在牦牛缺硒病的诊断中具有重要意义。     

Seasonal variation in selenium status of different classes of grazing goats in a semi-arid region of Pakistan

The selenium status of three different classes of goats ((i) female lactating, (ii) female non-lactating, and (iii) male goats) grazing semi-arid pasture in the southern part of the Punjab province, Pakistan and that of selenium concentration of soil and dietary sources, ingested by those animals were investigated during two different seasons of the year (winter and summer). Soil, forage, feed, water from the pasture and blood plasma, urine, faeces, and (if applicable) milk from these goats were collected fortnightly. The samples were analyzed for selenium concentrations. Soil selenium showed both seasonal and sampling periods effect on its concentration while forage selenium was affected only by the seasonal changes. No significant effect of seasons or fortnights on feed selenium level was observed. In fecal samples selenium concentration in lactating and non-lactating and plasma of male goats were affected by sampling periods. While fecal selenium in male goats showed significant effect on its concentration both seasonal and within fortnights. Severe deficient level of soil selenium during both seasons and marginal deficient level of forage selenium during summer were observed. Selenium concentrations in feed slightly exceeded the requirements of ruminants in feed during both seasons of the year. Plasma selenium concentrations in all goat classes were higher in winter than that in summer showing no seasonal or fortnight variation and its concentration was slightly lower in lactating goats as compared to other classes. On the bases of these results, it is concluded that overall selenium status of the goats based on plasma selenium concentration may be considered adequate mainly due to the mineral supplement provided all over the year, since soil and forage selenium concentrations were low to deficient.     

Mercury and selenium in wild mink (Mustela vision) from Norway

Levels of mercury, methylmercuri and selenium were determined in liver samples from wild mink (Mustela vision) caught in the Norwegian countries of Rogaland (38 samples), Sogn og Fjordane (15 samples) and Hedmark (18 samples). The average mercury levels from these counties were 2.6, 3.1 and 2.1 micrograms Hg/g wet weight, respectively. No significant differences in mercury levels were found. The methyl mercury levels (MeHg) were determined in 30 samples. A very strong positive correlation between total mercury (Hg) and methyl mercury (r = 0.91, P less than 0.001) was found. The average methyl mercury level was 35 per cent of total mercury. This indicates that wild mink has the ability to demethylate mercury. The selenium levels were determined in 35 samples. A strong positive correlation between the levels of total mercury and selenium (r = 0.87, P less than 0.001) was found. There was no correlation between age or nutritional condition and mercury level. In the present study mink was examined to see of it could be recommended as an indicator species for monitoring the local environment for mercury contamination. No definite answer to this question could be found. The study did reveal, however, that in all the counties studied there are individuals that are considerably contaminated with mercury.     

Intake and digestion of wheat forage by stocker calves and lambs

Because wheat forage contains high concentrations of N, NPN, digestible DM, and water, beef cattle and sheep require an adaptation period before positive BW are seen. The objective of the present experiment was to determine the impact of length of exposure of lambs and steers to wheat forage on BW gains, N retention, and forage digestibility. Sixteen steer calves (average BW = 210 +/- 12 kg) and 20 wether lambs (average BW = 31.5 +/- 2.0 kg) were randomly assigned to 1 of 2 treatment groups. Group 1 grazed a wheat pasture for 120 d during the winter, whereas group 2 was wintered on dormant warm-season grass pastures plus warm-season grass hay and plant-based protein supplements. In the spring (April 5), all lambs and steers grazed wheat pasture for 14 d and were then housed in metabolism stalls and fed freshly harvested wheat forage to determine forage digestibility and N metabolism. Data were analyzed for lambs and steers separately as a completely randomized design, using the individual animal as the experimental unit. Lambs and steers grazing wheat pasture for the first time in the spring had less ADG during the first 14 d than lambs (80 vs. 270 g, respectively; P = 0.01) and steers (1.06 vs. 1.83 kg, respectively; P = 0.09) that had grazed wheat pastures all winter. Digestibility of DM, NDF, and ADF fractions and N metabolism of freshly harvested wheat forage by lambs and steers were not different (P > 0.10) between the 2 treatment groups. Less ADG during the first 14 d of wheat pasture grazing is most likely the result of less DMI by nonadapted animals and is not due to diet digestibility or N metabolism.     

硒与奶牛免疫能力的相关性研究

为分析硒与奶牛免疫能力的关系,试验随机选取年龄、胎次、体况相近的泌乳奶牛50头。根据血清硒水平高低分为对照组和试验组,通过双抗体夹心法检测每组实验动物血液中的IL-2、IL-6、TNF-α含量。结果显示,试验组奶牛血清中的IL-2均低于对照组,但差异不显著(P>0.05),奶牛血清中硒水平与IL-2呈正相关(R=+0.133,P=0.356);试验组奶牛血清中的IL-6均高于对照组,但差异不显著(P>0.05),奶牛血清中硒水平与IL-6呈显著负相关(R=-0.28,P=0.049);试验组奶牛血清中的TNF-α均低于对照组,差异显著(P<0.05),奶牛血清硒水平与TNF-α呈显著正相关(R=+0.311,P=0.028)。该试验表明适当补充硒,可以提升奶牛机体免疫能力。