The potential of silage lactic acid bacteria-derived nano-selenium as a dietary supplement in sheep
The potential of silage lactic acid bacteria-derived nano-selenium as a dietary supplement in sheep
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DOI：
10.1071/an19258
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发表时间：
2019-01-01
影响因子：
1.4
通讯作者：
Davies, D. R.
中科院分区：
文献类型：
--
作者：
Lee, M. R. F.;Fleming, H. R.;Davies, D. R.
背景硒 (Se) 是动物细胞功能必需的微量元素，是谷胱甘肽过氧化物酶和 5-碘甲状腺氨酸脱碘酶的组成部分。在欧洲许多地区，由于土壤硒含量较低，牲畜饲料中经常缺乏硒。在饮食中补充硒化酵母（主要是硒代蛋氨酸）或无机亚硒酸钠是大多数家畜系统（包括反刍动物）的常见做法。乳酸菌已被证明可以将无机硒转化为主要为元素的纳米硒，纳米硒最近作为毒性较小的硒形式用于人类益生菌中。因此，青贮乳酸菌可能为反刍动物提供生物可利用的纳米硒的补充途径。目的在这里，我们报告了饲喂富含超营养水平纳米硒的接种青贮饲料（Selage）与对照接种青贮饲料（青贮饲料）对育肥羔羊及其产品中硒状态的影响，随后进行了第二项研究，其中调查了母羊的血液参数。方法在第一项研究中，40根据体重和性别将夏洛莱 x 萨福克羔羊（42 只，重 1.7 千克）配对，然后分配至两种治疗组，为期 8 周或 10 周。暂时评估了羊毛对硒的吸收以及粪便中硒的排泄。宰后报告血液和肌肉中的硒浓度、胴体特征和肉质。在第二项研究中，单独圈养的萨福克 x 骡母羊（n = 12；76 4.5 千克）提供与第一项研究相同的饮食。在开始时和 6 周后评估血液参数，并在整个研究过程中临时评估粪便和尿液的摄入量和排泄量。 主要结果 在第一项研究中，两个治疗组的干物质 (DM) 摄入量相似，均为 0.8 +/- 0.03 kg/天，但日粮中的硒浓度显着不同，导致青贮饲料和青贮饲料日粮的摄入量分别类似于 0.14 和 1.60 毫克/天。这反映在粪便（0.4 vs 2.0 mg/kg DM；P < 0.001）、羊毛（0.11 vs 0.25 mg/kg DM；P < 0.001）、血液（0.19 vs 0.46 mg/L；P < 0.001）和肌肉（0.31 vs 0.41 mg/kg：P < 0.01）中硒浓度较高。青贮饲料优于青贮饲料。经过 Selage 处理后，肉的颜色（色度）保质期显着延长（8.05 天 vs 9.2 天；P < 0.05）。在第二项试验中，对于饲喂青贮饲料的母羊，治疗 6 周后，血液中的硒代蛋氨酸从 0.21 增加到 0.25 毫克/升，硒代半胱氨酸从 0.25 增加到 0.35 毫克/升，而饲喂青贮饲料的母羊则没有变化。在研究期间，谷胱甘肽过氧化物酶增加，而血细胞比容、血红蛋白和血小板计数随着时间的推移而减少，但治疗之间没有差异。结论 Selage 治疗提供的纳米硒对绵羊来说是有效的，可以延长保质期，并且没有不良的血液学影响。意义 使用青贮饲料接种剂为反刍动物提供生物可利用的硒是有潜力的。需要进一步研究来确定最适合动物性能和产品质量的剂量。
Context Selenium (Se) is a trace element essential for cellular function in animals as a component of the enzymes glutathione peroxidase and iodothyronine-5-deiodinase. In many parts of Europe, Se is often deficient in livestock diets due to the low Se status of soil. Supplementation of diets with selenised yeast (predominately as seleno-methionine) or inorganic sodium selenite is common practice in most livestock systems, including ruminants. Lactic acid bacteria have been shown to convert inorganic Se into predominantly elemental nano-Se, which has been used recently in human pro-biotics as a less toxic form of Se. Therefore, silage lactic acid bacteria may provide a supplementation route of bioavailable nano-Se for ruminants.Aim Here, we report on the effect of feeding inoculated silage enriched with a supra-nutritional level of nano-Se (Selage) versus control inoculated silage (Silage) on the Se status of finishing lambs and their products, followed by a second study where blood parameters were investigated in ewes.Methods In the first study, 40 Charollais x Suffolk lambs (42 1.7 kg) were paired according to weight and sex, then allocated to the two treatments for 8 or 10 weeks. Uptake of Se into wool was temporally assessed, as well as excretion of Se into faeces. Selenium concentrations in blood and muscle, carcass characteristics and meat quality are reported postmortem. In the second study, individually penned Suffolk x Mule ewes (n = 12; 76 4.5 kg) were offered the same diets as in the first study. Blood parameters were assessed at the start and after 6 weeks, with intake and excretion into faeces and urine assessed temporally throughout the study.Key results In the first study, dry-matter (DM) intake was similar in both treatment groups, at 0.8 +/- 0.03 kg/day, but Se concentrations of the diets were significantly different, resulting in intakes of similar to 0.14 and 1.60 mg/day on the Silage and Selage diets, respectively. This was reflected in higher Se concentrations in faeces (0.4 vs 2.0 mg/kg DM; P < 0.001), wool (0.11 vs 0.25 mg/kg DM; P < 0.001), blood (0.19 vs 0.46 mg/L; P < 0.001) and muscle (0.31 vs 0.41 mg/kg: P < 0.01) on the Selage than on the Silage diet. Colour (chroma) shelf life of the meat was significantly higher on the Selage treatment (8.05 vs 9.2 days; P < 0.05). In the second trial, for ewes fed Selage, blood seleno-methionine increased from 0.21 to 0.25 mg/L and seleno-cysteine from 0.25 to 0.35 mg/L after 6 weeks on the treatment, whereas there was no change in ewes fed Silage. Glutathione peroxidase increased, whereas haematocrit, haemoglobin and platelet count were decreased across time during the study, but there was no difference between the treatments.Conclusions Nano-Se provided by the Selage treatment was shown to be available to sheep and improve shelf life, with no adverse haematological effects.Implications There is potential to use silage inoculants to provide bioavailable Se to ruminants. Further research is required to determine the most appropriate dose for animal performance and product quality.