高效液相色谱-电感耦合等离子体质谱法测定富硒蛋白多糖中纳米单质硒含量

本试验旨在建立高效、准确、快速测定富硒蛋白多糖中纳米单质硒含量的方法。将25 mg阴沟肠杆菌(Enterobacter cloacae)Z0206产富硒蛋白多糖样品悬浮在3 mL蒸馏水中,在3 mgⅩⅣ型蛋白酶作用下超声处理30 min(37℃),将酶解液离心得到的沉淀物(纳米单质硒)在常温下经双氧水-盐酸(H_2O_2-HCl)体系消解,所得溶液直接经高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析[以PRP X100阴离子色谱柱对样品中的亚硒根离子(SeO_2-3)进行分离,流动相组成为5 mmol/L柠檬酸水溶液(pH 4.5)],测得样品中纳米单质硒含量为2 439μg/g。以国家标准(GB/T 13883—2008)方法[样品以硝酸-高氯酸(HNO_3-HClO_4)体系消解处理,经氢化物发生-原子荧光(HG-AFS)分析]为对照,测得样品中纳米单质硒含量为2 450μg/g。2种方法的测定结果高度一致。与GB/T 13883—2008中描述的方法相比,采用本试验建立的氧化体系条件更温和、快速并且易于控制,适用于纳米单质硒的快速检测。     

用差分脉冲溶出伏安法直接测定牛奶中硒和铅

用差分脉冲阴极溶出伏安法（DPCSV）和差分脉冲阳极溶出伏安法（DPASV）分别测定土耳其奶样中的硒和铅。使用的是悬汞电极。本方法奶样用HNO3：HClO4(1:1)混酸湿法消化。奶样在0.1mol/L HCl中硒的DPCSV出峰电位在－0．56V，铅的DPASV出峰电位在－0．35V，硒和铅的富集电位为－0．2V，－0．5V。用标准加入法测定样品中硒和铅，其线性范围、相关系数分别为75－1．2μg/L和0．9981；185－8．7μg/L和0．9945。本方法测定痕量硒和铅简便、快速，不需要复杂仪器和冗长的分离过程，采集土耳其三个不同典型地区的奶样，硒和铅的含量在21．5－69．4和22．1－59．2μg/L(n=4-5)，相对标准偏差分别为10．3－10．7和6．8－9．9％。     

不同硒生物强化方式对火龙果硒含量的影响

为探究适用于提高火龙果硒含量的含硒肥料种类和施肥方式,以“金都1号”火龙果为试验材料,增施含硒有机肥和氨基酸硒肥,氨基酸硒肥又设置喷施（3种浓度）和淋施（3种浓度）两种施用方式,研究火龙果产量、果肉和茎硒含量的变化特征。结果表明,施用含硒肥料对火龙果产量无显著影响（p>0.05）。增施含硒有机肥和淋施氨基酸硒肥均显著提高火龙果果肉、茎硒含量（p<0.05）。所有处理组中,含硒有机肥料处理组果肉硒含量最高,达到0.019 3 mg/kg,是空白对照的5.7倍,淋施氨基酸硒肥处理组果肉硒含量范围在0.006 1 ~0.007 9 mg/kg。所有喷施氨基酸硒肥处理组果肉、茎硒含量与对照无显著差异（p>0.05）。结论：土壤施硒是火龙果更为有效的硒生物强化方式;在酸性土壤中,施用碱性含硒有机肥能更好地达到硒生物强化效果。     

日粮中添加富硒酵母生产富硒鸡蛋的研究

采用短期饲喂试验研究了富硒酵母硒在鸡蛋中的沉积。将600羽46周龄产蛋率约为80％的罗曼蛋鸡随机分为4个组，A组为对照组喂基础日粮(添加了0．3mg／kg无机硒，来源于亚硒酸钠)，B、C、D组为试验组，在基础日粮中分别加0．2、0．4、0．6mg/kg有机硒(来源于富硒酵母)。结果显示，日粮中加富硒酵母可显著提高鸡蛋中硒含量，但对蛋鸡生产性能无显著影响，硒主要存在于蛋黄中；A、B、C、D组蛋中硒平均含量分别为6．84、10．02、18．24、27．18μg/只；而且蛋黄中硒含量增高使蛋黄的维生素E水平也增高，富硒鸡蛋在贮藏中哈氏单位下降缓慢，可延长鸡蛋的贮藏期。     

叶面喷硒可提高甜樱桃果实品质并降低部分重金属的含量

正据《果树学报》2019年第6期《叶面喷施硒对甜樱桃硒和重金属含量及果实品质的影响》(作者戚霄晨等)报道,为了探讨叶面施用外源硒对甜樱桃叶片、果实中的硒及有害重金属含量、部分生化指标、果实品质的影响,以"美早"甜樱桃为试材,以亚硒酸钠(Na_2SeO_3)溶液为硒源,设置0、5、10、20和40 mg/L等5个质量浓度水平,于谢花后喷施叶片,1周后再喷施1次。结果表明,甜樱桃果实和叶片中的硒含量随施硒浓度的增加而递增,重金属镉和铅的含量均有不同程度降低。叶面喷硒可显著提高甜     

富硒酵母对水牛乳成分和乳硒含量的影响

试验研究了在饲粮中添加不同水平的富硒酵母对泌乳水牛的泌乳性能、乳成分、体细胞和乳硒含量的影响。试验选择16头尼里拉菲水牛,随机分为4组。对照组、试验1组、试验2组、试验3组分别在饲粮中添加0、0.30、0.45、0.60 mg/kg DM的富硒酵母,试验期为61 d,预饲期为7 d,正式试验期为54 d。结果表明:饲粮中添加酵母硒对水牛乳的乳蛋白、脂肪、乳糖、非脂固形物无显著影响(P0.05),整个试验期体细胞数正常;随着酵母硒添加量的增加,水牛乳乳硒的含量也随之增加。富硒酵母添加量为0.60 mg/kg DM时水牛乳中的乳硒含量最高,达到30.83μg/L。     

自然草地放牧牦牛脏器中硒浓度的研究

为掌握放牧牦牛脏器中硒浓度基础值及补无机硒后的变化 ,对 6头 1～ 4岁自然放牧牦牛 (投硒组 2头 ,按0 .2mg/kg体重肌肉内注射亚硒酸钠后第 42d ,对照群 4头未作处理 )部分脏器含硒量进行了测定 ,并对该地区 5 5头放牧牦牛血清中硒浓度进行了探讨。结果表明 :①各脏器中含硒量以肾脏中呈显著高值 (2 12 2～ 3 70 9μg/kg) ;②牦牛肌注亚硒酸钠后各脏器中含硒量均有增加 ,其中心脏 ,肝脏 ,血液中含硒量的增加极显著 (P <0 .0 0 1) ;③放牧牦牛血清中硒浓度呈 2 1.76± 4.70 μg/kg的低值。     

日粮中添加富硒桑叶粉对陕南白山羊屠宰性状和肌肉脂肪酸的影响

[目的] 研究日粮中添加富硒蛋白桑叶粉对陕南白山羊屠宰性状指标、肌肉理化特性指标及肌肉脂肪酸和硒含量的影响。[方法] 将30只3月龄陕南白山羊羯羊随机分为对照组和富硒桑叶组,每组15只;对照组饲喂基础日粮,富硒桑叶组在基础日粮中添加15%的富硒蛋白桑叶粉;试验期为60 d,预饲期15 d,正饲期45 d;试验结束时进行屠宰试验,测定屠宰性状及肌肉理化特性指标;采集试验羊背最长肌,测定肌肉脂肪酸含量和硒含量。[结果] 日粮中添加15%的富硒蛋白桑叶粉可显著（P<0.05）提高陕南白山羊肌肉pH_{1 h}值和失水率;富硒桑叶组的眼肌面积和胴体重大于对照组,但差异不显著（P>0.05）。在2组山羊的背最长肌中检测到19种脂肪酸,其中饱和脂肪酸5种,不饱和脂肪酸14种;2组山羊肌肉中饱和脂肪酸、单不饱和脂肪酸及多不饱和脂肪酸含量占脂肪酸总含量的比例相似,分别约为28%、67%、5%;富硒桑叶组肌肉中的γ-亚麻酸含量显著（P<0.05）高于对照组,但脂肪酸总含量低于对照组。与对照组相比,富硒桑叶组肌肉中硒含量有所升高,但差异不显著（P>0.05）;富硒桑叶组（0.071 3 mg/kg）和对照组（0.066 0 mg/kg）背最长肌硒含量均达到陕西省含硒肉类食品标准。[结论] 在陕南白山羊日粮中添加15%桑叶粉可在一定程度上改善产肉量、促进硒在肌肉中的富集、减少胴体脂肪沉积,但由于肌肉失水率显著升高,需在储存和运输过程中尽量避免水分丢失。     

免疫增强剂硒对雏鸡免疫功能的影响

300只1日龄南海黄雏鸡随机分为5组，Ⅰ－Ⅳ组为加硒试验组，Ⅴ组为不加硒对照组。全部试验鸡均饲喂不缺硒饲料（含硒0．18mg/kg)，并以饮水方式进行新城疫首免和2免。Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别于2次免疫前2d起连续3d以亚硒酸钠饮水给硒0．25、0．5、0．75、1．0mg/kg。结果表明，各组平均血清硒含量变化与饮水给硒剂量一致；Ⅰ－Ⅳ组的新城疫HI抗体滴度显著或极显著地高于Ⅴ组（P＜0．05或P＜0．01）；Ⅲ、Ⅳ组体重显著或极显著地高于Ⅴ组（P＜0．05或P＜0．01）；各加硒试验组特别是Ⅲ组在红细胞Ⅰ型补体受体（CR1）活性较Ⅴ组高；各组免疫器官指数未出现显著性差异。     

利用生物活性硒生产天然富硒牛奶的试验报告

选择泌乳期的健康黑白花奶牛15头,随机分为3组,每组5头。采用单因子试验设计,其中对照组只喂基础日粮,2个试验组分别加喂不同硒含量的生物活性硒预混料(第1组为30mg/kg,第2组为25mg/kg)各500g。试验结果表明,2组加喂生物活性硒预混料的奶牛乳液中乳硒含量分别比对照组提高了111.1%、127.7%,体细胞数分别下降了37.5%与34.8%,经方差分析,均为P<0.01,属于极显著有效。     

克孢灵(ClO2)叶面消毒对桑叶的药害及营养成分的影响

将主要成分为ClO2的蚕用消毒剂克孢灵用作桑树叶面消毒,当药剂质量浓度在200 mg/L以下时,对桑叶叶质没有不良影响;以100 mg/L以下质量浓度药液对桑叶作浸渍消毒时未发现叶片外观出现异常。经50~100mg/L克孢灵处理的桑叶,其水分、糖、蛋白质、脂肪等含量与对照相比没有明显变化,表明50~100 mg/L克孢灵用作桑树叶面消毒剂,对桑叶叶质没有不良影响。     

Effect of selenate as a feed supplement to dairy cows in comparison to selenite and selenium yeast

The main aim of this trial was to define the possible differences between selenite and selenate in their ability to increase the selenium (Se) concentration of milk, in comparison with organic Se. Dairy cows (n = 42) were fed a basal diet containing .10 to .12 mg Se/kg DM for 5 mo and were then divided into four groups of 10 or 11, as similar as possible in age and stage of lactation. During the next 84 d, the cows in three of the groups were supplemented with 3 mg of Se daily, whereas the cows in one control group remained unsupplemented. The Se supplement was given as sodium selenite, sodium selenate, or a Se yeast product. The total Se concentration of the diets varied with the cows' stage of lactation and was for the supplemented groups .24 to .31 mg/kg DM, but remained between .10 and .12 mg/kg in the control group. At the end of the trial, the mean whole blood Se concentrations in the selenite, selenate, yeast, and control groups were 138, 141, 165, and 104 microg/L, respectively. The Se concentration in plasma apparently reached a plateau level within 4 wk, at approximately 75 microg/L in the selenite group, 80 microg/L in the selenate group, and 90 microg/L in the yeast group. In the control group the mean concentration in plasma remained at approximately 50 microg/L. The increase of the activity of glutathione peroxidase (GSH-Px) in the erythrocytes was significantly higher in the supplemented groups than in the control group. The mean concentrations of Se in milk in the selenite, selenate, and yeast groups were 16.4, 16.4, and 31.2 microg/L, respectively, whereas the concentration remained at approximately 14 microg/L in the control group. The milk Se concentration reached a plateau within 1 wk after the start of Se supplementation. Dietary supplementation with selenite and selenate, thus, had only a limited effect on the Se concentration in milk, and there was no significant difference between the two inorganic compounds in any variable measured. Organic Se was much more effective than inorganic Se in increasing the concentration of Se in milk.     

喷施亚硒酸钠对紫花苜蓿干草产量和品质的影响

采用叶面喷施的方法研究了3个不同施硒水平(50、100、200 mg/kg)对紫花苜蓿Medicaco sativa干草产量及品质的影响.结果表明:一年4茬每茬次干草产量都随着施硒量的增加有降低的趋势,但对不同茬次的干草产量影响不同,适量喷施硒肥可以显著提高紫花苜蓿产量(P＜0.05),年产量以施肥量50 mg/kg的亚硒酸钠最高.喷施硒肥对每茬次营养物质含量的影响不同,4个处理紫花苜蓿粗蛋白、粗灰分及植株磷含量之间差异不显著,粗纤维及粗脂肪含量则随着喷施硒量的增加而增加,粗纤维以100 mg/kg处理最高,粗脂肪以200 mg/kg处理最高,但紫花苜蓿营养物质年积累量都随着施硒量的增加而降低,其中以50 mg/kg处理最高,要显著高于对照.     

溴虫腈在桑叶中的残留毒性与降解动态检测

为了保证桑园喷施杀虫剂溴虫腈后的养蚕用叶安全,采用食下毒叶法测定了溴虫腈对家蚕的残留毒性,用气相色谱法检测了喷药后不同时间桑叶中的药剂残留动态变化。结果表明:桑园内分别喷施250、200、150、100、50mg/L溴虫腈,检测到药剂在桑叶的残留毒性期分别为>5 d、>5 d、3 d、1 d和0 d;200 mg/L溴虫腈在桑叶中的降解动态方程为C=95.335e-0.159 9t(R2=0.906 8),半衰期为4.33 d,此检测方法的最低检出药剂残留质量比为3.97×10-4mg/kg;桑树盛产期喷洒100 mg/L溴虫腈后2 h、1 d、3 d、5 d、7 d、14 d、21 d和28 d,药剂在桑叶中的残留量分别为40.969、39.814、20.226、18.726、9.975、5.522、2.774和0.026 mg/kg;200 mg/L和100 mg/L溴虫腈2次喷施处理桑叶21 d后的最终残留量分别为12.958、4.242 mg/kg。10%溴虫腈悬浮剂用于桑树害虫或害螨防治的建议使用浓度为100 mg/L,采叶安全间隔期为施药后5 d。     

Selenium and glutathione peroxidase levels in lambs receiving feed supplemented with sodium selenite or selenomethionine

Twenty-one 6 months old female lambs were divided into 7 groups and fed a basal diet containing 0.13 mg Se/kg. The basal diet was further supplemented with 0, 0.1, 0.5 or 1.0 mg Se/kg either as sodium selenite or as selenomethionine, and was fed for 10 weeks. Both feed additives produced an increase in the selenium concentration in the tissues analysed. Significant correlations were found between the concentrations of selenomethionine or sodium selenite added to the feed and the subsequent tissue levels. However, the selenium levels seemed to plateau at approximately 0.5 mg Se/kg of supplemented sodium selenite. The total glutathione peroxidase (GSH-Px) activity of the tissues increased when the selenium supplementation increased from 0 to 0.1 mg/kg for both selenium compounds. With further increase in selenium supplementation the GSH-Px activity in the tissues plateaued except in the blood where the activity continued to rise with increasing selenomethionine supplementation. The selenium dependent GSH-Px activity in the liver rose with increasing selenomethionine supplementation, but approached a plateau when 0.1 mg Se/kg as sodium selenite was added to the feed. The selenium concentration in whole blood responded more rapidly to the selenium supplementation than did GSH-Px activity. The experiment indicates that the optimal selenium concentration in the feed is considerably higher than 0.1 mg Se/kg, and that selenium levels of 1.0 mg/kg in the feed do not result in any risk for the animals or the consumers of the products.Key words: dietary selenium, lambs, selenium concentrations, glutathione peroxidase activities, tissues     

桑叶植酸的提取条件优化及桑叶和蚕粪中的植酸含量检测

建立高效提取桑叶植酸的方法,并应用于检测分析不同品种、不同成熟度桑叶中的植酸含量和蚕粪中的植酸含量,有助于进一步开展降低桑叶中的植酸含量及提高桑叶营养利用率的研究。运用Design-Expert 8.0.4 Trial软件的Box-Behnken模型,分析不同提取条件因子对桑叶植酸提取效果的影响作用为原料质量浓度>提取液中盐酸的浓度>浸提时间,确定最佳提取条件:提取液为1.25%盐酸+0.1 g/mL硫酸钠,浸提时间为2.18 h,原料质量浓度为0.05 g/mL。在此优化条件下提取桑叶和蚕粪中的植酸,并应用比色法测定5个桑品种春季成熟叶、嫩叶以及秋季成熟叶、嫩叶中的植酸平均质量比分别为3.98、3.55、3.75、3.52 mg/g,5龄幼虫蚕粪中的植酸含量为3.78 mg/g,与桑叶中的植酸含量接近。检测结果说明桑叶中的植酸随着桑叶的成熟其含量不断增加,家蚕不能吸收利用植酸态的磷。     

The influence of dietary selenium as selenium yeast or sodium selenite on the concentration of selenium in the milk of Suckler cows and on the selenium status of their calves

The aim of this trial was to determine whether the selenium status of suckling calves could be improved by supplementing their dams' diet with organic Se instead of sodium selenite. A herd of 103 Hereford cows, which were on grass paddocks all year round, was divided into two groups. Both groups had free access to a mineral supplement that contained 30 mg of Se/kg; for one group the source of the Se was a Se yeast product, and for the other group the source was sodium selenite. The basal feed contained .02 mg of Se/kg DM. During the trial, the mean daily consumption of the mineral supplement was approximately 110 g/cow. The calving season started in the middle of March and ended in the middle of May. Blood samples were taken from 11 cows and their calves in the yeast group and from nine in the selenite group at the end of April and again at the beginning of June, and milk samples were taken at the same times. At both samplings, the concentration of Se in whole blood and the activity of glutathione peroxidase (GSH-Px) in the erythrocytes of the cows and calves in the yeast group were higher than in the samples from the animals in the selenite group. The same pattern was seen for plasma, except for the cows at the first sampling. The mean concentrations of Se in whole blood from calves in the yeast and selenite groups were 130 and 84 microg/L, respectively, and plasma concentrations were 48 and 34 microg/ L, respectively. Mean Se concentration in the milk from the yeast group (17.3 microg/L) was higher than that in milk from the selenite group (12.7 microg/L). There were significant correlations (r = .59 to .68) between the concentrations of Se in the cow's milk or cow's whole blood compared with Se concentrations in the calves whole blood and plasma or with the erythrocyte GSH-Px activity of the calves. The Se status of the calves in the selenite group was considered to be marginal, but the status of the calves in the yeast group was considered to be adequate. Supplementation of the suckler cows' diet with organic Se in the form of Se yeast rather than sodium selenite improved the Se status of their calves when the Se was mixed into a mineral supplement containing 30 mg of Se/kg. In practice, such supplementation would probably eliminate the risk of nutritional muscular degeneration in suckling calves.     

根施甜菜碱对盐胁迫下桑树幼苗生理生化反应的影响

为探讨桑树的耐盐性栽培措施,对盐胁迫下桑树幼苗根施外源甜菜碱,调查不同处理下幼苗生长发育及相关生理指标的变化。结果表明,根施2.5~10.0 mmol/L甜菜碱,可以提高盐胁迫(100 mmol/L NaC l)下桑树叶片的叶绿素、可溶性糖和脯氨酸含量,保持叶片含水率,调节K+/Na+离子平衡,减少丙二醛含量,从而减轻盐胁迫对桑树生长的抑制作用;根施甜菜碱浓度以2.5~5.0 mmol/L较为合适。     

蛋鸡日粮中添加富硒酵母对鸡蛋中硒含量及分布的影响

试验选用产蛋率约为80%的罗曼褐蛋鸡35只,随机分为7组,进行为期30d的饲养试验。A组为对照组,饲以基础日粮,其余6组为试验组,B、C、D组在基础蛋鸡日粮中分别添加0.2mg/kg、0.5mg/kg、1mg/kg硒的亚硒酸钠,E、F、G组在基础蛋鸡日粮中分别添加0.2mg/kg、0.5mg/kg、1mg/kg硒的富硒酵母。试验过程中记录蛋鸡的生产性能,每隔7d从各试验组鸡所产的鸡蛋中任取3枚,测定鸡蛋中硒的含量,并于试验的第14、15天,28、29天从A、C、F组每组各取5枚鸡蛋分别测定蛋黄和蛋清的硒含量。结果显示,日粮中添加硒对蛋鸡生产性能无显著影响,能极显著提高鸡蛋中硒含量,并且硒主要存在蛋黄中,添加富硒酵母组蛋硒含量较亚硒酸钠组提高更为显著。     

Repletion of blood selenium concentrations in weaned beef calves

Eighty-three weaned beef calves severely deficient (less than 20 micrograms/L) in blood selenium (Se) were allotted by sex, weight and breed to one of six regimens of Se supplementation for 108 days to examine the efficacy of various Se supplementation programs and to monitor the repletion rate of blood Se concentrations. Cattle in treatment 1 received an IM injection of sodium selenite and an ad libitum feeding of 20 mg Se/kg salt-mineral mixture. Salt-mineral mixtures (treatments 2, 3, 4 and 5) were formulated to contain 20, 40, 80 and 160 mg Se/kg supplement, respectively, and were offered free-choice. Treatment 2 served as the selenium-treated control because 20 mg Se/kg supplement was the maximum permissible by FDA in commercial salt-mineral preparations at the time of this study. Cattle in treatment 6 received a salt-mineral supplement which contained no Se but dried brewers grain (434 micrograms Se/kg) was incorporated in the ration as an organic source of Se and fed at a rate of 1.1 kg/head/day. There was a within group time/treatment interaction (P less than 0.01) among all treatments as blood Se concentrations significantly increased over time. Final mean whole blood Se concentrations for treatments 1-6 were 87.8, 60.6, 95.1, 123.1, 154.2 and 91.4 micrograms/L, respectively. Treatments 1, 3, 4, 5 and 6 effectively increased and maintained whole blood Se concentrations at adequate levels (greater than 70 micrograms/L) by day 84. Treatment 2 (control) increased blood Se during the 108-day study, but blood Se concentrations never exceeded marginal levels (50-70 micrograms/L). Cattle consumed less salt-mineral supplement as the concentration of Na selenite increased from 20 to 160 mg Se/kg supplement.