日粮添加赛乐硒对奶牛产奶量和乳品质的影响

选用35头处于干奶期40d、泌乳期相近和上胎平均日产奶量20kg的中国荷斯坦奶牛，采用完全随机区组设计分为7组，即：对照组、亚硒酸钠组（7．5mgSe／d、15mgSe／d和22．5mgSe／d）和赛乐硒组（7．5mgSe／d、15mgSe／d和22．5mgSe／d），研究赛乐硒和无机硒对奶牛泌乳性能和乳硒含量的影响。结果表明：在泌乳期30d、60d、90d赛乐硒组较对照组显著提高奶牛产奶量、乳蛋白率和乳干物质含量，有提高乳脂率和乳糖含量的趋势。试验前各组乳硒差异不显著，试验期赛乐硒组较无机硒组、对照组显著提高乳硒含量。     

赛乐硒对西门塔尔牛营养物质消化和氮平衡的影响

选用7头体重420kg、2．5岁的中国西门塔尔牛。采用7×7拉丁方设计,研究添加赛乐硒（7．5、15和22．5m$e／d）和亚硒酸钠（7．5、15和22．5mgSe／d）对日粮营养物质消化和氮平衡的影响。结果表明,7．5～15mg／d赛乐硒组OM、CP、EE、NFE、NDF和ADF表观消化率显著提高,15-22．5m岛『d亚硒酸钠组显著降低。赛乐硒较亚硒酸钠显著提高了采食氮、消化氮、沉积氮和消化氮,沉积氮比例。以上结果表明,赛乐硒较无机硒能更有效促进营养物质的消化与利用。提高抗氧化能力,其适宜添加量为7．5—15mg／d。     

两种形式的硒对奶牛红细胞内几种抗氧化酶活力影响的研究

实验通过在缺硒地区奶牛血中不同形态有机硒 (C6H12 N2 O4Se2 )及无机硒 (Na2 SeO3 )测定红细胞内几种抗氧化酶的活力变化来说明有机硒与无机硒的不同生物学效应。实验表明 ,有机硒与无机硒均可使红细胞内抗氧化酶酶活有所改变 ,其中谷胱甘肽过氧化物酶 (GSH -PX)与超氧化物岐化酶 (SOD)差异性显著 (P <0 .0 5 ) ,且有机硒的生物学效应明显高于无机硒     

微量元素在母猪饲养生产中的应用

1硒 硒是谷胱甘肽过氧化物酶（GSHPX）的组成成分，与维生素E一起起到抗氧化的作用。两者有协同作用，但不可相互完全替代。硒存在机体的多种组织中，但是组织沉积数量主要取决于饲料中有机硒的水平。比较有机硒和无机硒源时，     

有机硒对羔羊生长性能及抗氧化能力的影响

为了研究有机硒对羔羊生长性能和抗氧化能力的影响,试验选用30只体重20kg左右的滩羊羔羊,分成3组,对照组不添加硒,2个补硒组分别添加富硒酵母、亚硒酸钠,其剂量以硒计均为0.1mg/kg日粮,试验期为60d。结果表明：①富硒酵母不能提高羔羊的生长性能。②在30和60d时,2个补硒组血液中谷胱甘肽过氧化物酶（GSH-Px）活性、SOD酶活性,均显著或极显著高于对照组（P＆lt;0.05或P＆lt;0.01）;血清中MDA含量,均极显著低于对照组（P＆lt;0.01）。上述结果说明有机硒提高羔羊抗氧化能力的效果优于无机硒。     

超剂量硒对产蛋鸡生产性能及其全血、(胸)肌肉和全蛋中含硒量的影响

用45周龄海赛克斯产蛋鸡144只进行饲养试验，探讨了不同超剂量硒（有机硒和无机硒）对产蛋鸡生产性能以及其全血、胸肌和全蛋中含硒量的含量变化。基础料中含硒量为0.3mg／kg。有机硒（氨基酸硒）或无机硒（亚硒酸钠）的硒添加量分别都是1、5、10、15mg／kg。结果表明：1．饲粮中添加超剂量硒时，鸡的采食量下降。其下降的程度随硒浓度的增加而加重。当填加量高达15mg／kg时，鸡产蛋停止，但无一死亡。当添加量在10mg／kg时，鸡的产蛋量下降。当添加量在1和5mg／kg时，对鸡的产蛋量无影响，而无机硒组则稳中有降。2．超剂量硒组的全血、胸肌和全蛋的含硒量随硒浓度的增加而上升。在前3周时逐渐上升，而到第4周时则有所下降或趋向稳定。3．饲料粮中加硒量达到10mg／kg以上时，蛋鸡出现中毒症状，其主要中毒症状与缺硒时的症状相似。     

母猪日粮中添加不同硒源对其乳硒及仔猪健康状况影响的比较

为了研究补硒对硒从母猪转运到仔猪的影响,试验对哺乳母猪饲粮中不补充硒或分别以亚硒酸钠、酵母硒形式补充0．3mg／kg硒,高于NRc对饲粮硒的推荐量（0．15mg／kg）。未强化硒的玉米一豆粕型基础饲粮为阴性对照组,饲粮中含有较高的内源性硒（Se：0．20～0．23mg／kg）。52头母猪从分娩前60d饲喂到哺乳第14d。分别在分娩前60d、30d、分娩当天、产后14d,从每个处理组选择6头母猪采血,测定血清硒浓度。收集分娩后12h内的初乳,及哺乳第14d的乳汁。在仔猪出生和断奶（14d）当天,从每窝仔猪中选择5头（每个处理组12窝仔猪）采血,混合血清,检测硒、免疫球蛋白G的浓度,及谷胱甘肽过氧化物酶的活性。各处理组母猪在妊娠期间的血清硒水平下降;哺乳期间逐渐增加。分娩时,饲喂酵母硒（P〈0．06）的母猪血清硒浓度高于没有补硒的母猪。与饲喂亚硒酸钠的母猪相比,饲喂酵母硒的母猪其初乳和常乳（第14d）中硒浓度增加（P〈0．01）。与饲喂基础饲粮组相比,酵母硒组仔猪在出生时血清硒浓度增加（P〈0．01）。14日龄仔猪血清硒浓度在各个处理组间没有差异。仔猪血清IgG和谷胱甘肽过氧化物酶活性不受饲粮硒源的影响。给妊娠和哺乳母猪补充0．3mg／kg有机硒或无机硒,窝产死胎数减少。但是,只有饲喂有机硒（酵母硒）的母猪,仔猪出生时血清硒水平更高。有机硒组母猪初乳和14d常乳中硒浓度增加程度高于无机硒组。     

硒代蛋氨酸对断奶仔猪生长性能、抗氧化及免疫性能的影响

文章旨在研究日粮添加有机硒(硒代蛋氨酸)对断奶仔猪生长性能、血清抗氧化和免疫性能的影响。试验选择26 d断奶的杜×长×大仔猪1080头[平均体重(9.82±1.18)kg],随机分为6组,每组4个重复,每个重复45头。对照组饲喂基础日粮(硒含量为0.03 mg/kg),无机组饲喂在基础日粮中添加0.4 mg/kg硒(亚硒酸钠),有机硒组在基础日粮中分别添加0.2、0.4、0.6和0.8 mg/kg硒(硒代蛋氨酸),试验共进行42 d。结果显示:日粮添加0.4和0.8 mg/kg有机硒较对照组显著降低了断奶仔猪22～42 d的料重比(P <0.05)。0.4 mg/kg有机硒组较对照组和0.4 mg/kg无机硒组显著提高了血清GSH-Px和T-AOC活力(P <0.05)。与对照组相比,0.2和0.4 mg/kg有机硒组显著提高了肝脏GSH-Px活力(P <0.05),而0.2 mg/kg有机组肝脏T-AOC活力最高(P <0.05)。与对照组相比,无机硒组和有机硒组显著降低了肝脏和肌肉MDA含量(P <0.05)。与对照组相比,无机硒组和有机硒组显著降低了肝脏MDA含量(P <0.05)。0.6 mg/kg有机硒组较对照组、0.4 mg/kg无机硒组和0.2、0.4 mg/kg有机硒组显著提高了断奶仔猪21 d血清硒含量(P <0.05);与对照组相比,0.4和0.6 mg/kg有机硒组显著提高了仔猪42 d血清硒含量(P <0.05)。0.8 mg/kg有机硒组较对照组和0.4 mg/kg无机硒组显著提高了仔猪42 d血清硒含量(P <0.05)。结论 :日粮添加硒代蛋氨酸可以改善断奶仔猪的生长性能,提高其抗氧化性能和血清硒含量,断奶仔猪适宜的硒代蛋氨酸添加水平为0.2～0.4 mg/kg(以硒计)。     

有机硒对育肥猪抗热应激能力的影响

本试验的目的是研究有机硒对育肥猪抗热应激能力的影响。将180头70kg左右的三元杂交(杜×长×大)育肥猪随机分成3组,每组5个重复,每个重复12头,试验进行42d。对照组为基础日粮,不添加硒制剂;试验组在基础日粮基础上分别添加亚硒酸钠和酵母硒,最终含硒量都为0.5mg/kg。试验结果表明:(1)无机硒能显著降低血清中MDA的含量(P0.05),能降低肝脏和肾脏中MDA的含量,但差异不显著(P0.05)。有机硒能够显著降低肝脏、肾脏和血清中MDA的含量(P0.05)。有机硒对MDA的降低效果显著大于无机硒(P0.05);(2)有机硒和无机硒都能够提高血清和肾脏中GSH-Px酶活性,但只有有机硒提高效果显著(P0.05)。相较于无机硒,有机硒对肾脏和血清中的GSH-Px酶活有更好的促进作用(P0.05);(3)无机硒能够提高肝脏和血清中的SOD酶活,但差异不显著(P0.05)。有机硒能够显著提高肝脏和血清中SOD酶活(P0.05)。与无机硒相比,有机硒能够显著提高肾脏和血清中SOD酶活(P0.05)。     

赛乐硒对西门塔尔牛矿物质存留率的影响

选用7头体重420kg,2．5岁的西门塔尔牛,采用7×7拉丁方设计．研究日粮添加赛乐硒（7．5、15和22．5mg硒／d）和亚硒酸钠（7．5、15和22．5mg硒／d）对日粮矿物质存留率的影响。结果表明：赛乐硒各组硒的表观存留率较亚硒酸钠组和对照组显著提高,钙、磷、锌和铜表观存留率较亚硒酸钠组提高。铁、钼和硫表观存留率无显著变化。赛乐硒组血清硒浓度较亚硒酸钠组显著提高,血清铁浓度无显著变化,赛乐硒组血清铜浓度增加。以上结果表明赛乐硒较无机硒能更有效促进矿物质的消化与利用,硒适宜添加量为7．5～15mg／d。     

Brain selenium accumulation in rat pups of selenium supplemented mothers

Selenium is essential for normal mammalian development. Being a component of antioxidant enzyme, glutathione peroxidase, it plays a major role in protecting the cells from free radical damage. The level of glutathione peroxidase was directly related to the amount of selenium present in various tissues and organs. A decrease in selenium leads to various pathological changes in humans as well as in various laboratory animals. The aim of the present study was to understand whether there is an increase in the level of selenium in different brain regions of rat pups whose mothers were supplemented with selenium, either 2 or 4 mg/l of their drinking water throughout the period of their pregnancy. There was a significant increase in the level of selenium in the cerebellum, cortex and hypothalamic and hippocampal tissues of selenium supplemented mothers as compared with those of non-supplemented mothers. The brain stem of these animals did not show any significant difference in the level of selenium. Furthermore, the differences in the level of selenium between the rat pups of 2 mg/l selenium supplemented mothers and 4 mg/l selenium supplemented mothers were not statistically significant. These studies suggest that supplementation of selenium to mothers during the period of their pregnancy can selectively increase the level of this trace element in different brain regions. Further studies are necessary to understand the significance of selective accumulation of selenium in specific brain regions on brain development and function.     

聚焦硒元素第三部分发展趋势

2000年重新修订的欧盟食品与饲料法正促使食物生产链发生重要的变化,该法律要求生产商提高产品质量,同时要求他们能够证明所生产产品的安全性和功效,否则必须退出欧盟市场。一个利用特殊酵母菌株生产的硒酵母产品成为欧盟新食品与饲料法颁布后首个获准生产的饲料添加剂之一,由此反映了社会对资源和创新的需求。     

Effect of subcutaneous selenium injection and supplementary selenium source on blood selenium and glutathione peroxidase in feedlot heifers

This study measured the effect on glutathione peroxidase (GSH-Px) and selenium (Se) in whole blood and plasma associated with subcutaneous Se injections in beef heifers fed organic or inorganic Se. Heifers (n = 120) were randomly divided into 2 groups, 1 of which received subcutaneous Se injections. Both groups were given the same total mixed ration with 3 mg of organic or inorganic Se daily. Until week 2, heifers that had received Se injections showed higher concentrations of plasma Se and GSH-Px and whole blood Se (P < 0.001) than those having had no injections. Concentrations of plasma Se and GSH-Px were higher in the group receiving organic Se than the group receiving inorganic Se. Whole blood GSH-Px concentrations increased significantly (P < 0.001) throughout a 12-week period but were not affected by Se source. Combination of Se injections and supplementation could help maintain normal Se and GSH-Px blood status in beef heifers during the first few weeks in the feedlot.     

Effect of inorganic selenium supplementation on selenium retention in postweaning swine

A total of 64 weanling pigs was used in a randomized complete-block experiment to evaluate the efficacy of various inorganic Se levels on weekly Se balance measurements over a 5-wk post-weaning period. Four-week-old weaned pigs were fed a 20% protein, corn-soybean meal diet supplemented with 0, .3, .5 or 1.0 ppm Se from sodium selenite. Eight pigs were allotted by weight, litter and sex to each metabolism crate. A 2-d preliminary period followed by a 5-d collection period was conducted for five weekly periods. Feed intake was provided ad libitum but was similar between dietary Se levels. Fecal Se excretion increased each week and with increasing dietary Se level. Apparent digestibility of Se was relatively constant for each period when inorganic Se was fed, averaging approximately 70%, whereas it ranged between 30 to 40% for pigs fed the basal diet during wk 2 through 5. Urinary Se decreased during the postweaning periods for pigs fed the basal diet, but increased linearly as dietary Se increased during the initial 2-wk postweaning period and then quadratically during wk 3 through 5. There was a net loss of Se from the body when the Se-unsupplemented basal diet was fed during the initial 2 wk postweaning, whereupon, it became positive. Selenium retention in pigs supplemented with inorganic Se increased each week of the trial. When Se retention was expressed in relation to Se intake, the resulting regression was linear (R2 = .99), suggesting that Se retention in the postweaning pig increased in direct proportion to the amount consumed when diets contained up to 1.0 ppm Se.     

利用产朊假丝酵母转化无机硒为有机硒的研究

对富硒酵母进行筛选并对发酵条件进行优化,得到富硒酵母的最适发酵条件:麦芽汁12°Be、培养基加Se量15mg/l、250ml三角瓶装量40ml、初始pH值为6.0、发酵时间40h、温度26℃、转速250r/min,经此培养所得的富硒酵母中的Se含量达到了1451.31μg/g。     

啤酒废酵母硒对肉鸡组织硒含量的影响

本试验旨在研究啤酒废酵母硒对肉鸡组织硒含量的影响。选用225羽1日龄平均体重为(42.78±1.08)g的AA商品代肉鸡(公母混合),随机分成5组,每组3个重复,每个重复15羽,对照组日粮为以Na2SeO3形式在基础日粮中补充硒0.1mg/kg,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组日粮为以酵母硒形式在基础日粮中补充硒0、0.1、0.2、0.3mg/kg,饲养期42d。结果表明:(1)肉鸡羽毛、肌肉和肝脏中硒的含量随着酵母硒添加量的增加和时间的延长显著提高,并表现出较强的线性关系;(2)与基础日粮组相比,酵母硒组肉鸡组织硒含量极显著增加(P0.05),以0.3mg/kg的添加量最好;硒的沉积顺序为肝脏羽毛肌肉。本试验结果提示,由啤酒废酵母制备的酵母硒可以提高肉鸡组织硒含量。     

Effect of selenium source and dose on selenium status of mature horses

This study was conducted to determine the effects of either dietary Se source or dose on the Se status of horses. Twenty-five mature horses were blocked by BW and randomly allocated to 1 of 5 dietary treatments that comprised the same basal diet that differed only in Se source or dose. Treatments were as follows: negative control (0.085 mg of Se/kg of DM), 3 different dietary concentrations of supplemental organic Se (Se yeast; 0.2, 0.3, and 0.4 mg of total Se/kg of DM), and positive control (0.3 mg of total Se/kg of DM) supplemented with Na selenite. Horses initially received the control diet (6 kg of grass hay and 3 kg of concentrate per horse daily) for 56 d to allow diet adaptation. After the period of diet adaptation, horses were offered their respective treatments for a continuous period of 112 d. Jugular venous blood samples were collected before the morning feed on d 0, 28, 56, 84, and 112. Whole blood and plasma were analyzed for total Se, glutathione peroxidase activity in whole blood (GPX-1) and plasma, and thyroid hormones (thyroxine and triiodothyronine) in plasma. The proportion of total Se as selenomethionine (SeMet) or selenocysteine in pooled whole blood and plasma samples was determined on d 0, 56, and 112. Data were analyzed as repeated measures. Total Se in blood and plasma and GPX-1 activity were greater in all supplemented horses (P < 0.001, except P < 0.01 for GPX-1 in horses supplemented with the least dose of Se yeast) with a linear dose effect of Se yeast for whole blood and plasma Se (P < 0.001) and a quadratic dose effect (P < 0.05) for whole blood GPX-1 activity. A plateau for total Se in plasma was achieved within 75 to 90 d, although this was not observed in blood total Se or GPX-1 activity. On d 84 and 112, horses supplemented with Se yeast showed greater total Se in blood (P < 0.05) compared with horses supplemented with Na selenite, and a source effect (P < 0.05) was observed in the relationship between total blood Se and GPX-1 activity. Selenocysteine (the predominant form of Se in whole blood and plasma) increased in all horses supplemented with Se. The SeMet content of whole blood and plasma increased in horses supplemented with Se yeast, but it was not observed in those supplemented with selenite. The rate of increase in SeMet over time was greater in whole blood (P < 0.05) and plasma (P = 0.10) with the Se yeast product. In conclusion, Se yeast was more effective than Na selenite in increasing total Se in blood, mainly as consequence of a greater increase of the proportion of Se comprised as SeMet, but it did not modify GPX-1 activity.     

Effect of selenium supplementation and source on the selenium status of horses

This study was conducted to determine the effect of Se supplementation and source on the Se status of horses. Eighteen 18-mo-old nonexercised horses were randomly assigned within sex to 1 of 3 treatments: 1) control (CTRL, no supplemental Se, 0.15 mg of Se/kg of total diet DM); 2) inorganic Se (INORG, CTRL + 0.45 mg of Se/kg of total diet DM from NaSeO3); or organic Se [ORG, CTRL + 0.45 mg of Se/kg of total diet DM from zinc-L-selenomethionine (Availa Se, Zinpro, Corp., Eden Prairie, MN)]. Horses were acclimated to the CTRL diet (7.1 kg of DM alfalfa hay and 1.2 kg of DM concentrate per horse daily) for 28 d. After the acclimation period, the appropriate treatment was top-dressed on the individually fed concentrate for 56 d. Jugular venous blood samples were collected on d 0, 28, and 56. Middle gluteal muscle biopsies were collected on d 0 and 56. Muscle and plasma were analyzed for Se concentrations. Glutathione peroxidase activity was measured in muscle (M GPx-1), plasma (P GPx-3), and red blood cells (RBC GPx-1). Data were analyzed as a repeated measures design. Mean plasma Se concentration on d 28 and 56 was greater (P < 0.05) for Se-supplemented horses compared with CTRL horses, and tended (P < 0.1) to be greater in ORG vs. INORG on d 28. Mean muscle Se concentration and P GPx-3 activities increased (P < 0.05) from d 0 to 56 but were not affected by treatment. Mean RBC GPx-1 activity tended to be greater (P < 0.1) in ORG than INORG or CTRL horses on d 28, and tended to be greater (P < 0.1) for INORG compared with ORG horses on d 56. Mean RBC GPx-1 activity of INORG and ORG horses was not different from that of CTRL on d 56. Mean M GPx-1 activity decreased (P < 0.01) from d 0 to 56. In conclusion, zinc-L-selenomethionine was more effective than NaSeO3 at increasing plasma Se concentration from d 0 to 28; however, both supplemental Se sources had a similar effect by d 56. No difference in Se status due to Se supplementation or source could be detected over a 56-d supplementation period by monitoring middle gluteal muscle Se, M GPx-1, or P GPx-3. Results for RBC GPx-1 also were inconclusive relative to the effect of Se supplementation and source.     

Thyroid hormone concentrations in selenium deficient and selenium sufficient cattle

Selenium deficient calves when compared to selenium supplemented calves had increased plasma thyroxine concentrations and decreased plasma tri-iodothyronine concentrations. These changes in the selenium deficient calves were accompanied by significant increases in plasma urea and creatinine concentrations and decreased plasma alkaline phosphatase activity. The demonstration that low selenium status can cause imbalances in thyroid hormone metabolism may provide an explanation for some of the effects of the deficiency.