Serum glutathione peroxidase activity and blood selenium in pigs

Blood serum glutathione peroxidase activity and blood selenium concentration were measured in blood samples from pigs subjected to experimentally induced selenium deficiency and dietary selenium supplementation on graded levels. A highly significant correlation between blood selenium and serum GSH-Px activity in pigs, especially in selenium deficient pigs, was demonstrated. There was also a strong relationship between blood selenium concentration and serum GSH-Px activity in pigs receiving dietary selenium at graded levels. Serum GSH-Px activity exhibited an excellent close-response relationship to dietary selenium. Linear regression analysis showed that the increased serum GSH-Px activity was a function of the dietary selenium concentration. The fitness of serum in monitoring slight changes of the selenium status of pigs with help of the estimation of GSH-Px activity was discussed. The measurement of serum GSH-Px activity seems to provide a useful and rapid means for defining selenium requirements and for identifying selenium deficiency in growing pigs.     

1～21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量的研究

本试验旨在研究饲粮不同硒添加水平对1~21日龄岭南黄羽肉仔鸡生长性能和抗氧化性能的影响,以探讨快大型岭南黄羽肉仔鸡饲养前期的饲粮硒适宜供给量。选用1日龄健康、发育良好的快大型岭南黄羽肉公雏鸡1 200只,根据体重随机分为5个组,每组6个重复,每个重复40只鸡,试验1组(对照组)饲喂基础饲粮(硒水平为0.039 mg/kg),试验2~5组饲粮在基础饲粮中分别添加0.075、0.150、0.225和0.300 mg/kg硒,试验期21 d。结果表明:本试验条件下:1)与对照组相比,饲粮添加0.300 mg/kg硒显著降低1~21日龄岭南黄羽肉仔鸡的末重(P0.05),显著提高料重比(P0.05),且0.300 mg/kg硒添加组的平均日增重显著低于其他各水平硒添加组(P0.05)。2)与对照组相比,饲粮添加0.075和0.150 mg/kg硒显著提高21日龄岭南黄羽肉仔鸡的血浆谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05),饲粮添加0.225和0.300 mg/kg硒显著降低血浆丙二醛(MDA)含量(P0.05)。各水平硒添加组的红细胞GSH-Px活性均显著高于对照组(P0.05)。3)与对照组相比,饲粮添加0.075、0.150和0.225mg/kg硒显著提高21日龄岭南黄羽肉仔鸡的肝脏GSH-Px活性(P0.05),0.075和0.150 mg/kg硒添加组的肝脏MDA含量显著低于对照组和0.300 mg/kg硒添加组(P0.05)。综合考虑,为获得较好生长性能和抗氧化性能,1~21日龄岭南黄羽肉仔鸡饲粮硒适宜添加水平为0.075 mg/kg,基础饲粮中硒水平为0.039 mg/kg,则1~21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量为0.114 mg/kg;以肝脏MDA含量为依据,通过非线性回归分析估测得到1~21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量为0.130 mg/kg。     

不同硒源及水平对肉鸡组织硒含量及抗氧化功能的影响

本文旨在研究和比较不同硒源及水平对爱拔益加(AA)肉鸡生长性能、组织硒含量和抗氧化功能的影响,并探讨在生产中应用较低水平(0.20 mg/kg)有机硒替代较高水平(0.30 mg/kg)无机硒的可行性.选用1日龄AA肉仔鸡600只,随机分为5组,分别饲喂基础饲粮(对照组)及在基础饲粮中添加0.30 mg/kg硒(以亚硒酸钠形式)(SS组)、0.20 mg/kg硒(以酵母硒形式)(SY Ⅰ组)、0.30 mg/kg硒(以酵母硒形式)(SYⅡ组)和0.30 mg/kg混合硒(亚硒酸钠和酵母硒形式硒各0.15mg/kg)(MS组)的试验饲粮,每组6个重复,每个重复20只鸡.试验期42 d.结果表明:1)SYⅡ组肉鸡前期平均日采食量显著低于对照组(P＜0.05),饲粮添加各水平有机硒均显著降低了肉鸡全期平均日采食量(P ＜0.05或P＜0.01).2)与对照组和SS组相比,添加各水平有机硒均显著提高了肉鸡胸肌中的硒含量(P＜0.01),且以SYⅡ组最高,显著高于其他各组(P＜0.01);SY Ⅰ组和SYⅡ组肉鸡血浆中的硒含量显著高于对照组(P ＜0.05或P＜0.01);添加各水平有机硒均显著提高了42 d肉鸡肝脏中的硒含量(P ＜0.05或P＜0.01).3)在试验前期(1 ～21 d),较SS组,SYⅡ组肉鸡血浆谷胱甘肽过氧化物酶(GSH-Px)和总超氧化物歧化酶(T-SOD)的活性均显著提高(P＜0.05);较对照组,SS组、SY Ⅰ组和SYⅡ组肉鸡肝脏T-SOD的活性均显著提高(P＜0.05或P＜0.01).在试验后期(22 ～42 d),较对照组,SS组、SY Ⅰ组和SYⅡ组肉鸡血浆和肝脏GSH-Px的活性均显著提高(P＜0.05或P＜0.01),各添加有机硒组肉鸡的血浆丙二醛含量均显著降低(P＜0.05或P＜0.01);与对照组相比,MS组肉鸡肝脏过氧化氢酶(P＜0.05)和GSH-Px的活性均显著提高(P＜0.01).由此可知,饲粮添加0.30 mg/kg酵母硒能够提高肉鸡组织硒沉积量,对其生长性能和抗氧化功能的改善效果最佳;饲粮添加0.20 mg/kg的酵母硒替代0.30 mg/kg亚硒酸钠,在改善肉鸡的生长性能、提高组织硒含量和抗氧化功能方面是可行的.     

Comparative effect of selenium in wheat, barley, fish meal and sodium selenite for prevention of exudative diathesis in chicks

Groups af White Leghorn chicks obtained from dams deprived on selenium (Se), were fed from hatching a low-Se-vitamin E basal diet alone, or supplemented with 0.02, 0.04, 0.06 or 0.08 mg Se/kg diet, as sodium selenite (Na2SeO₃ · 5H₂O), wheat, barley or fish meal. Prevention of the Se-vitamin E deficiency responsive disease exudative diathesis (ED) as it was clinical observed, induction of the plasma Se dependent enzyme glutathione peroxidase (GSH-Px) activity, and Se concentration in the cardiac muscle were observed to be dietary Se level and source dependent. Slope ratio assay was applied to estimate the biological availability of Se in the natural sources relative to Se in sodium selenite. For the prevention of ED, the bioavailability of Se in wheat, barley and fish meal was 99, 85 and 80 %, respectively. The increase in the plasma GSH-Px activity revealed a bioavailability for Se in wheat, barley and fish meal of 79, 71 and 66 %, respectively. Using retention of Se in the cardiac muscle as the bioassay, a bioavailability of 108, 87 and 100 % was calculated for wheat, barley and fish meal Se, respectively.     

酵母硒对肉仔鸡的生物安全性评价

本试验旨在研究饲粮添加不同水平酵母硒对爱拔益加(AA)肉仔鸡生长性能、血液血红蛋白含量和红细胞压积、血浆生化指标、器官指数和组织结构变化的影响,进而评价酵母硒对肉仔鸡的生物安全性。试验采用单因子完全随机设计,选用288只1日龄AA肉仔鸡,随机分为4个组,每个组6个重复,每个重复12只鸡(公母各占1/2)。各组分别在玉米-豆粕型基础饲粮中添加0、0.4、2.4和4.9 mg/kg(以硒计)的酵母硒试验。试验期为42 d。结果表明:1)与对照组相比,饲粮添加0.4和2.4 mg/kg酵母硒显著提高了22~42日龄肉仔鸡平均日采食量(P0.05);饲粮添加0.4、2.4和4.9 mg/kg酵母硒显著提高了1~42日龄肉仔鸡平均日增重(P0.05),而各酵母硒添加组之间差异不显著(P0.05)。2)饲粮添加不同水平酵母硒除对21日龄肉仔鸡血浆尿素氮含量和谷胱甘肽过氧化物酶(GSH-Px)活性以及42日龄肉仔鸡血浆GSH-Px活性有显著影响(P0.05)外,对其他血浆生化指标均无显著影响(P0.05)。与对照组相比,各酵母硒添加组21和42日龄肉仔鸡血浆GSH-Px活性随着酵母硒添加水平的增加均显著提高(P0.05),且饲粮添加2.4 mg/kg酵母硒显著降低了21日龄肉仔鸡血浆尿素氮含量(P0.05)。3)饲粮添加不同水平酵母硒对21和42日龄肉仔鸡血液血红蛋白含量和红细胞压积及42日龄肉仔鸡器官指数均无显著影响(P0.05),且并未引起主要器官的组织结构变化。综上所述,肉仔鸡饲粮中酵母硒的添加水平为0.4 mg/kg(饲粮中总硒含量为0.41 mg/kg)时,具有10倍的安全系数,即饲粮中以酵母硒形式添加硒对肉仔鸡是安全的。     

The relationship of erythrocyte glutathione peroxidase to blood selenium in swine

The erythrocyte glutathione peroxidase activity and blood selenium have been investigated in swine fed a Se deficient diet with, and without, selenium supplementation. A highly significant correlation (r = 0.90) between erythrocyte glutathione peroxidase and blood selenium was found.     

Influence of feeding thermally peroxidized lipids on growth performance, lipid digestibility,and oxidative status in nursery pigs

Three experiments were conducted to evaluate oil source and peroxidation status (experiment 1) or peroxidized soybean oil (SO; experiments 2 and 3) on growth performance, oxidative stress, and digestibility of dietary ether extract (EE). In experiment 1, palm oil (PO), poultry fat (PF), canola oil (CO), and SO were evaluated, while in experiments 2 and 3, only SO was evaluated. Lipids were either an unheated control (CNT) or thermally processed at 90 °C for 72 hr, being added at 10%, 7.5%, or 3% of the diet in experiments 1, 2, and 3, respectively. In experiment 1, 288 pigs (body weight, BW, 6.1 kg) were fed 1 of 8 factorially arranged treatments with the first factor being lipid source (PO, PF, CO, and SO) and the second factor being peroxidation status (CNT or peroxidized). In experiment 2, 216 pigs (BW 5.8 kg) were fed 1 of 6 treatments consisting of 100%, 90%, 80%, 60%, 20%, and 0% CNT SO blended with 0%, 10%, 20%, 40%, 80%, and 100% peroxidized SO, respectively. In experiment 3, 72 pigs (BW 5.8 kg) were fed either CNT or peroxidized SO. Pigs were fed 21 d with feces collected on day 12 or 14 and pigs bled on day 12 blood collection. In experiment 1, an interaction between oil source and peroxidation status was observed for averaged daily gain (ADG) and average daily feed intake (ADFI; P = 0.10) which was due to no impact of feeding pigs peroxidized PO, PF, or SO on ADG or ADFI compared with feeding pigs CNT PO, PF, or SO, respectively; while pigs fed peroxidized CO resulted in reduced ADG and ADFI compared with pigs fed CNT CO. There was no interaction between oil source and peroxidation status, and no lipid source effect on gain to feed ratio (GF; P ≥ 0.84), but pigs fed the peroxidized lipids had a lower GF compared with pigs fed the CNT lipids (P = 0.09). In experiment 2, feeding pigs diets containing increasing levels of peroxidized SO resulted in reduced ADG (quadratic, P = 0.03), ADFI (linear, P = 0.01), and GF (quadratic, P = 0.01). In experiment 3, feeding peroxidized SO at 3% of the diet reduced ADG (P = 0.11) and ADFI (P = 0.13), with no observed change in GF (P = 0.62). Differences in plasma protein carbonyls, glutathione peroxidase, and vitamin E due to feeding peroxidized lipids were inconsistent across the 3 experiments. Digestibility of dietary EE was reduced in pigs fed peroxidized PO or SO (P = 0.01, experiment 1) and peroxidized SO in experiments 2 and 3 (P ≤ 0.02). In conclusion, the peroxidation status of dietary lipids consistently affects growth performance and EE digestibility but has a variable effect on measures of oxidative stress.     

Relative bioavailability of selenium yeast for broilers fed a conventional corn–soybean meal diet

The present study was conducted to assess the relative bioavailability of selenium (Se) as Se yeast (SY) relative to sodium selenite (SS) for broilers fed a conventional corn–soybean meal diet. A total of 360 one-d-old Arbor Acres commercial broilers were randomly assigned to 5 treatments with 6 replicates per treatment in a completely randomized design involving a 2 (Se sources: SY and SS) × 2 (added Se levels: 0.20 and 0.40 mg Se/kg) factorial design of treatments plus 1 (a Se-unsupplemented control diet) for 42 days. The results showed that Se concentrations in plasma, liver, heart, breast muscle, pancreas and kidney of broilers on d 21 and 42, glutathione peroxidase (GSH-Px) activity in the pancreas on d 21 as well as in the breast muscle and pancreas on d 42, and GSH-Px mRNA levels in the liver, heart, breast muscle and pancreas on d 21 increased linearly (p < .03) as levels of added Se increased. Furthermore, a difference (p ≤ .05) between SY and SS was detected for Se concentrations in plasma, liver, heart, breast muscle, pancreas and kidney, GSH-Px activity in pancreas on both d 21 and 42, as well as pancreatic GSH-Px mRNA level on d 21. Based on slope ratios from the multiple linear regressions of the above indices, the Se bioavailabilities of SY relative to SS (100%) were 111%–394% (p ≤ .05) when calculated from the Se concentrations in plasma, liver, heart, breast muscle, pancreas, kidney and GSH-Px activities in pancreas on d 21 and 42, as well as GSH-Px mRNA level in pancreas on d 21. The results from this study indicated that the Se from SY was more available for enhancing the Se concentrations in plasma or tissues and the expression and activity of GSH-Px in pancreas of broilers than the Se from SS.     

Effect of feeding different sources of selenium on growth performance and antioxidant status of broilers

ABSTRACT

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0–35 d broiler chicken diets.

2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source.

3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0–35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001).

4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.     

不同硒源及硒水平对大鼠生长性能、血清抗氧化能力和组织硒沉积的影响

本试验旨在考察不同硒源及硒水平对大鼠生长性能、血清抗氧化能力及组织硒沉积的影响,并以亚硒酸钠和商品酵母硒(酵母硒B)为参比,对本课题组用糖蜜和尿素为发酵底物研制的酵母硒(酵母硒A)生物学效价进行评定.将硒耗竭2周后的70只8周龄左右Wistar雌性大鼠称重,随机分到10个处理,每个处理7个重复,每个重复1只大鼠,分别饲喂不同处理的饲粮21d.处理1不添加任何形式的硒源,处理2～9在基础饲粮中分别以亚硒酸钠或酵母硒A的形式添加0.1、0.2、0.3和0.4mg/kg硒,处理10以酵母硒B形式添加0.3mg/kg硒.结果表明:1)不同硒源及硒水平对大鼠生长性能、血清谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶活性影响不显著(P＞0.05);2)组织硒含量随饲粮硒水平的升高极显著增加(P＜0.01),添加酵母硒A组大鼠组织硒含量显著高于亚硒酸钠组(P＜0.05);3)以亚硒酸钠为参比,血清GSH-Px活性及肝脏、肾脏和肌肉硒含量作为判定指标,酵母硒A的相对生物学效价分别为95.9％、127.5％、114.5％和101.2％;4)添加酵母硒A和酵母硒B对大鼠生长性能、血清抗氧化能力的影响不显著(P＞0.05),但添加酵母硒A组大鼠肾脏硒含量极显著高于酵母硒B组(P＜0.01),而酵母硒B在肌肉中有更多的硒沉积(P＜0.01).结果提示:1)硒源对大鼠组织硒沉积有较大影响,酵母硒相对于亚硒酸钠具有更高的生物学效价,但不同酵母硒之间存在一定的差异;2)饲粮硒水平对大鼠血清抗氧化能力影响较小,以血清GSH-Px活性为衡量标准,0.1mg/kg硒的酵母硒和亚硒酸钠都能满足大鼠的需要,但更高水平的酵母硒可以使大鼠组织中有更多硒的储备.     

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     

饲粮中硒添加水平对产蛋高峰期临武鸭产蛋性能、蛋品质、血清抗氧化指标和蛋硒含量动态变化的影响

本试验旨在研究饲粮中硒添加水平对产蛋高峰期临武鸭产蛋性能、蛋品质、血清抗氧化指标和蛋硒含量动态变化的影响。试验选用29周龄体况良好、产蛋率接近的正处于产蛋高峰期的临武鸭200只,随机分为5组,每组5个重复,每个重复8只。对照组饲喂基础饲粮(不额外补充硒源,实测硒含量为0.15 mg/kg)45 d,Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组分别在基础饲粮中以酵母硒形式添加0.10、0.20、0.40、0.80 mg/kg的硒,饲喂35 d添加硒饲粮后改喂基础饲粮10 d。结果显示:1)饲粮中硒添加水平对蛋鸭产蛋性能和蛋品质各指标均无显著影响(P0.05)。2)与对照组和Ⅰ组相比,饲粮中添加0.40和0.80 mg/kg的硒可以显著提高蛋鸭血清中硒和谷胱甘肽(GSH)含量以及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05),显著降低血清中丙二醛(MDA)含量(P0.05)。3)随试验天数的增加,对照组和Ⅰ组蛋硒含量无显著变化(P0.05),而Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量均呈现先升高后降低的趋势,且均在试验第9天达到峰值。试验第7、9、13、17、21、28和35天,Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量显著高于对照组和Ⅰ组(P0.05);停喂添加硒饲粮的第1~4天,Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量仍显著高于对照组(P0.05);停喂添加硒饲粮的第5~8天,Ⅲ组和Ⅳ组蛋硒含量显著高于对照组(P0.05);停喂添加硒饲粮的第9天,各试验组蛋硒含量均衰减至与对照组相同水平(P0.05)。由此可见,饲粮中添加不同水平的酵母硒形式的硒对产蛋高峰期临武鸭的产蛋性能和蛋品质均无不良影响。饲粮中添加0.40和0.80 mg/kg酵母硒形式的硒可以提高产蛋高峰期临武鸭的蛋硒含量、血清硒含量和抗氧化能力,延长蛋硒的存留时效。综合考虑各因素,产蛋高峰期临武鸭饲粮中硒(以酵母硒形式添加)的适宜添加水平为0.40 mg/kg。     

硒的生化特性与谷胱甘肽系统

介绍了硒的生理生化特性,重点阐述了硒与谷胱甘肽系统在抗氧化防御体系中的作用以及硒蛋白的研究进展。硒和谷胱甘肽(GSH)系统在氧化防御反应中起着关键性作用。其中GSH的主要功能是直接阻断氧化物生成和促进抗氧化物生成的还原反应;此外,GSH在代谢、细胞信号传导和蛋白质间相互作用中也具有辅助性功能,还可调节机体防御反应。硒在哺乳动物细胞中的保护作用受含硒氨基酸如硒半胱氨酸、硒蛋氨酸的调控。谷胱甘肽过氧化物酶(GSH-Px)的活性位点含有硒半胱氨酸残基。其它含硒蛋白(如硒蛋白P和硫氧还蛋白还原酶)也具有抗氧化特性。合成的有机硒复合物(如Ebselen)在机体氧化应激中是一种极具应用前景的抗氧化剂。硒蛋白和有机硒复合物在预防过亚硝酸盐的生成中也起着重要作用。     

饲粮中添加不同硒源对产蛋鸡生产性能和抗氧化能力的影响

本试验研究了饲粮中添加亚硒酸钠、酵母硒、蛋氨酸硒和纳米硒对产蛋鸡生产性能、鸡蛋品质、血浆抗氧化能力和鸡蛋硒含量的影响,旨在为产蛋鸡饲粮中硒的合理使用提供理论依据。选取18周龄健康、产蛋率相近的海兰灰产蛋鸡540只,随机分为5组,每组6个重复,每个重复18只。对照组饲喂不添加硒的基础饲粮(总硒含量0.08 mg/kg),其他4组添加0.30 mg/kg硒,分别来自亚硒酸钠、酵母硒、蛋氨酸硒和纳米硒(实测饲粮硒含量分别为0.37、0.38、0.34和0.41 mg/kg)。试验预试期1周,正试期8周。结果表明:1)不同硒源对产蛋鸡的生产性能和蛋品质均无显著影响(P0.05)。2)与对照组相比,饲粮中添加0.30 mg/kg 4种硒均显著提高了血浆谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05)。试验4周末,纳米硒组GSH-Px活性最高;8周末,酵母硒组和纳米硒组GSH-Px活性较高。与对照组相比,饲粮中添加4种硒源均能够提高血浆总抗氧化能力(T-AOC),且纳米硒组在4和8周末均显著高于其他各组(P0.05)。4种硒源对血浆超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量均无显著影响(P0.05)。3)与对照组相比,基础饲粮中添加4种硒源均可显著提高鸡蛋中硒含量(P0.05),其中酵母硒组显著高于其他3组(P0.05)。由此可见,基础饲粮中添加4种硒源对产蛋鸡生产性能和鸡蛋品质无显著影响;4种硒源均可显著提高血浆GSH-Px活性和T-AOC,且酵母硒和纳米硒效果更好;与亚硒酸钠、蛋氨酸硒和纳米硒相比,酵母硒在增加鸡蛋硒含量方面更加有效。     

胱氨酸类硒源对产蛋鸡蛋品质、抗氧化能力和蛋中硒含量的影响

本试验旨在研究饲粮中添加硒代胱氨酸(SeC)、L-硒甲基硒代半胱氨酸(L-MSC)、L-硒代半胱氨酸(L-SeCys)和亚硒酸钠(SS)对产蛋鸡生产性能、蛋品质、抗氧化能力和蛋中硒含量的影响,以期为富硒鸡蛋的生产提供依据。选用26周龄体况良好、产蛋率接近的海兰灰蛋鸡450只,随机分为5个组,每组6个重复,每个重复15只鸡。对照组饲喂基础饲粮(不额外补充硒),其他4组饲粮在基础饲粮中添加0.30 mg/kg硒,分别来自SeC、L-MSC、L-SeCys和SS,各组饲粮中硒含量实测值分别为0.08(对照组)、0.36(SeC组)、0.35(L-MSC组)、0.31(L-SeCys组)和0.37(SS组)mg/kg。预试期1周,正试期4周。结果表明:1)与SS组和对照组相比,胱氨酸类硒源各组产蛋鸡的平均蛋重、产蛋率和料蛋比均无显著差异(P0.05)。L-SeCys组平均日采食量在试验1~2周时显著低于对照组(P0.05)。2)与SS组和对照组相比,胱氨酸类硒源各组产蛋鸡的蛋白高度、哈氏单位、蛋壳强度、蛋形指数、蛋黄和蛋白比例均无显著差异(P0.05)。试验第4周末,SS组蛋黄颜色显著高于其他各组(P0.05);SeC和SS组蛋壳厚度显著高于其他各组(P0.05),L-MSC和L-SeCys组蛋壳厚度显著高于对照组(P0.05);对照组蛋壳比例显著低于各试验组(P0.05)。3)与SS组和对照组相比,胱氨酸类硒源各组产蛋鸡的血浆谷胱甘肽过氧化物酶(GSH-Px)活性显著升高(P0.05);SeC和SS组血浆总超氧化物歧化酶(T-SOD)活性显著高于对照组(P0.05);胱氨酸类硒源各组血浆丙二醛(MDA)含量与SS组相比无显著差异(P0.05);对照组血浆总抗氧化能力(T-AOC)显著低于其他各组(P0.05),L-MSC组的血浆T-AOC最高,显著高于SS组(P0.05)。4)与对照组相比,饲粮中添加胱氨酸类硒源显著提高了蛋中硒含量(P0.05),其中L-MSC组最高;胱氨酸类硒源各组蛋中硒含量和硒转化率均高于SS组(P0.05)。由此可见,饲粮中添加3种胱氨酸类硒源可增强机体抗氧化水平,提高蛋中硒含量,其中SeC和L-MSC效果更好。     

不同来源硒对异育银鲫的生物学效应研究

以异育银鲫为试验动物,研究不同来源的硒(蛋氨酸硒和纳米硒)对其生长性能、肌肉生化组成和谷胱甘肽过氧化物酶活性的影响。试验分为3个处理,日粮中添加硒浓度分别为0 mg/kg(对照组)、0.5 mg/kg(蛋氨酸硒)和0.5 mg/kg(纳米硒),每个处理3个重复。结果显示,与对照组相比,蛋氨酸硒和纳米硒均可显著提高异育银鲫的末重、相对增重率以及谷胱甘肽过氧化物酶活性(P<0.05),但是蛋氨酸硒处理组和纳米硒处理组间差异不显著。纳米硒处理组肌肉中硒含量显著高于其他两组(P<0.05),蛋氨酸硒处理组肌肉中硒含量显著高于对照组(P<0.05)。研究表明,饵料中添加一定浓度的蛋氨酸硒和纳米硒具有一定的生物学效应。     

饲粮中添加维生素E和有机硒对攸县麻鸭产蛋性能、蛋品质、血清生化指标及咸蛋蛋黄品质的影响

本试验旨在研究饲粮中添加维生素E和有机硒对攸县麻鸭产蛋性能、蛋品质、血清生化指标及咸蛋蛋黄品质的影响.选用200只健康的处于产蛋高峰期的攸县麻鸭,随机分为4个组,每组5个重复,每个重复10只鸭.对照组(Ⅰ组)饲喂基础饲粮,3个试验组(Ⅱ、Ⅲ、Ⅳ组)分别在基础饲粮中添加50 IU/kg维生素E、0.2 mg/kg硒、0....     

Effects of dietary distillers dried grains with solubles (DDGS) on growth performance,oxidative stress,and immune function in broiler chickens

Distillers dried grains with solubles (DDGS) from corn contain relatively large amounts of polyunsaturated fatty acids and some yeast components, which may increase oxidative stress and alter immune function, respectively, when fed to broilers. Therefore, the study was undertaken to assess the effects of distillers dried grains with soluble (DDGS) on broilers under immunosuppressive challenge. One-day-old male broiler chickens (300) were assigned to 2 treatments with 6 replicates pretreatment. Birds were fed diets formulated to contain 0, 15% corn-based DDGS, respectively. The experimental diets were fed for 6 weeks in 2 phases. On day 21, serum IgA, IgG content and malondialdehyde (MDA), glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), and total antioxidant activity (T-AOC) capacity were analyzed. Chickens were then randomly allotted to 1 of 4 treatment groups: negative control (NC) corn-soybean meal diet without dexamethasone (DEX) challenge, positive control (PC) corn-soybean meal diet with (DEX) challenge, 15% DDGS without DEX challenge (D), 15% DDGS with DEX (D+DEX). Based on these results, dietary DDGS did not influence ADG, ADFI and F:G of 21 d, 28 d and 42 d chicks (P > 0.05), however, DEX affected ADG and F:G of 28 d chicks remarkably (P < 0.05). Relative weights of liver, abdominal fat, spleen, thymus, and bursa were influenced by DEX challenge on d 28 (P < 0.05). DDGS reduced serum T-AOC, T-SOD, whereas increased IgA, IgG and MDA of 21-day-old broilers significantly (P < 0.05). Dietary DDGS also reduced liver T-SOD of 21-day-old broilers significantly (P < 0.05). Based on real-time PCR, 28 d chicks fed DDGS had a greater relative abundance of mRNA encoding IL-4 and IL-6 (P < 0.05), whereas DEX decreased the expression of GPX, IL-6, IL-10 (P < 0.05). Thus, 15% dietary DDGS inclusion has the beneficial effects on immune functions for broilers to some degree.     

Effects of dietary levels of selenium-enriched yeast and sodium selenite as selenium sources fed to growing-finishing pigs on performance, tissue selenium, serum glutathione peroxidase activity, carcass characteristics, and loin quality.

This research evaluated the efficacy of inorganic and organic Se sources for growing-finishing pigs, as measured by performance and various tissue, serum, carcass, and loin quality traits. A total of 351 crossbred pigs were allotted at an average BW of 20.4 kg to six replicates of a 2x4 factorial experiment in a randomized complete block design. Pigs were fed diets containing Se-enriched yeast (organic) or sodium selenite (inorganic), each at .05, .10, .20, or .30 mg Se/kg diet. A non-Se-fortified basal diet was a ninth treatment group. Five pigs per pen were bled initially and at 30-d intervals with serum analyzed for Se and glutathione peroxidase (GSH-Px) activity. At 55 kg BW, one pig per pen from each of three replicates was killed, and tissues were collected for Se analysis. At 105 kg BW, the remaining pigs in the three replicates were killed, carcass measurements were collected, tissues were analyzed for Se, and loin quality was evaluated for pH, drip loss, and lightness. No performance or carcass measurement benefit resulted from either Se source or dietary Se levels. Pigs had a lower serum Se concentration and GSH-Px activity when the basal diet was fed, but both increased as dietary Se level increased (P<.01). Serum GSH-Px activities were increased by pig age and reached a plateau when the diet contained approximately .10 mg Se/kg (P<.01) at d 30, and 60 of the trial, and at .05 mg Se/kg diet at d 90 of the trial. The organic Se group fed .05 and .10 mg Se/kg had serum GSH-Px activities that tended to be lower than those of pigs fed the inorganic Se source, but GSH-Px activities in both groups were similar at higher Se levels. Tissue Se contents increased linearly as the dietary Se level increased, but the increase was markedly higher when organic Se was fed, resulting in an interaction (P<.01) response. Loin drip loss, pH, and lightness were unaffected (P>.15) by organic Se source or level, but there was a trend for a higher drip loss (P = .11) and a linear (P<.01) increase in loin paleness when the inorganic Se level increased. These results indicate that neither Se source nor Se level had an effect on pig performance or carcass measurements, but organic Se source increased tissue Se concentrations. Inorganic Se may, however, have a detrimental effect on loin quality, as reflected by higher drip loss and a paler color. Using serum GSH-Px activity as the measurement criterion, the supplemental dietary Se requirement did not seem to exceed .10 and .05 mg Se/kg diet for the growing and finishing phases, respectively, when added to a basal diet containing .06 mg Se/kg.     

Vitamin E, selenium, and polyunsaturated fatty acid concentrations and glutathione peroxidase activity in tissues from pigs with dietetic microangiopathy (mulberry heart disease)

Tissues of 27 pigs with spontaneous dietetic microangiopathy (DM) and of 27 control pigs that died of causes unrelated to vitamin E and selenium (E-Se) deficiency were analyzed for alpha-tocopherol, Se and polyunsaturated fatty acid (PUFA) concentrations and for glutathione perioxidase (GSH-Px) activity. These variables (except for GSH-Px) also were measured in rations fed to control pigs and pigs with DM. Swine with DM had lower heart and liver alpha-tocopherol concentrations than did control pigs. Heart and kidney Se concentrations and heart and liver PUFA concentrations were similar in pigs of either group. Diets fed to both groups of pigs contained similar content of alpha-tocopherol, Se, oil, and PUFA; alpha-tocopherol and Se concentrations in the diets of both groups of pigs were high. In spite of apparently adequate amount of dietary alpha-tocopherol, results indicate that pigs with DM had lower tissue alpha-tocopherol concentration than did control pigs. Spontaneous DM is associated with altered alpha-tocopherol metabolism, but is unrelated to alterations in dietary Se and PUFA contents and tissue Se and PUFA concentrations and GSH-Px activity.