富硒猪肉的研究进展

中国约2/3地区缺硒,我国人群普遍存在硒摄入不足及不均衡现象。该文阐述了硒的营养作用和富硒产品的开发途径,重点综述了富硒猪肉的研究进展。     

食用菌市场新宠——富硒蘑菇

眼下，富硒农产品逐渐走上百姓的餐桌，由于硒元素具有明显的防癌、抗癌等作用，故富硒产品大受市场欢迎，诸如富硒大米、富硒大葱、富硒苹果等，对较前卫的消费者而言，已不是什么新鲜事了；自去年秋冬以来，富硒农产品中又一新贵亮相市场——富硒蘑菇 的出现，     

硒的功能及富硒酵母对肉鸡性能影响的研究(一)

研究表明,硒(Se)是人和动物必需的一种微量元素,具有重要的生物学意义。但是,长期以来,硒(Se)一直被认为是一种毒性元素。近10多年来,随着对硒(Se)生物学功能研究的不断深入,在畜禽日粮中添加硒(Se)添加剂已经越来越普遍,特别是富硒酵母(selenium-enriched yeast)等有机硒添加剂的研制与应用,为有效利用硒(Se)提高畜禽生产性能、改善畜禽产品品质展现了广阔的前景。     

富硒紫云英生产富硒牛奶的研究

本试验研究了利用富硒紫云英提高乳硒含量的效果及其对产奶量、乳脂、乳蛋白、乳中矿物质、全血GSH—Px活性的影响。试验表明：紫云英能促进奶牛对硒的吸收。以富硒紫云英的效果最好．可较大幅度增加乳中硒的含量；饲喂普通紫云英也可增加乳中硒的含量．添加无机硒也可增加乳中硒的含量．但利用率低。富硒紫云英、普通紫云英和无机硒对乳脂、乳糖和乳蛋白含量和乳中K^＋、Na^＋含量没有显著的影响。但对乳中Ca^2＋、Mg^2＋含量影响较大。全血GSH—Px活性受饲料中硒水平的影响显著。紫云英对奶牛血中GSH—Px活性比无机硒、对照组均明显提高．富硒紫云英、无机硒和普通紫云英处理组中GSH—Px活性比对照组分别提高了151．23％、87．15％和46．53％。富硒紫云英对产奶性能有较大的提高．生产周期相对延长。     

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。     

重庆地区富硒水果发展现状与对策

富硒赋予了水果的另一种保健价值。重庆地区土壤硒富集存在较大差异,在一些特别区域土壤富硒显著,具备发展富硒水果的资源优势,富硒产品开发也取得了较好成效。然而在重庆发展富硒水果产业中也存在一些问题。本文综述了重庆水果发展现状、富硒土地开发进展、富硒水果生产现状以及认证渠道和消费途径,提出进一步研究和开发对策。     

江西:于都全力打造富硒农业产业

2019年5月20日,习近平总书记到于都县考察时指示,于都县有丰富的富硒土壤资源,要充分利用这个资源,打造富硒农产品品牌,让富硒农产品在市场上更加畅销。2021年3月,于都县富硒产业发展中心成立,整合果茶局、粮食收贮中心、农业开发办、经济作物站、农业培训学校、种子管理站.     

富硒鸭蛋市场前景研究

硒是人体必需的微量元素.研究表明,低硒或缺硒人群通过适量补硒不但能够预防肿瘤、肝病等的发生,而且可以提高机体免疫能力,维护心、肝、肺、胃等重要器官正常功能,预防老年性心、脑血管疾病的发生.笔者在合肥市进行的富硒产品调查统计基础上,结合国内其他地区富硒产品的开发和市场现状,对富硒鸭蛋的市场价值与推广潜力进行探析,并提出可行性策略与建议.     

利用富硒酵母生产富硒鸡蛋的技术研究

 采用短期饲喂试验研究富硒酵母硒在鸡蛋中的沉积。结果显示,在蛋鸡日粮中加入不同浓度的酵母硒(有机硒),短期饲喂即可通过鸡本身的生物转化获得含硒量较高,同时又符合食品卫生标准(GB 2762-2005)中硒限量0.5 mg/kg的鸡蛋,且对蛋鸡生产性能无显著影响,对鸡蛋品质也没有不良影响,鸡蛋中的硒主要存在于蛋黄中。     

富硒鸡蛋的研究进展

硒是体内重要的微量元素,食品中含硒相对较少,不能完全满足机体需求,本文就硒的功能及富硒鸡蛋的开发进行综述。     

富硒酵母对肉鸡生产性能的影响研究

试验选择富硒酵母,在肉鸡饲料中添加4个水平的富硒酵母(硒添加水平0、0.1、0.2、0.3mg/kg),以确定富硒酵母在肉鸡饲料中的适宜添加量。结果表明:添加后,肉仔鸡生产性能无显著差异,但可显著提高42日龄肉仔鸡的增重和耗料量。本试验中,饲料中硒的适宜添加水平为0.1mg/kg。     

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。     

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.     

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.     

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.     

The correlation between serum selenium and blood selenium in cattle.

The selenium (Se) concentration of paired blood and serum samples from cattle was determined by 2 methods: 1) atomic absorption spectroscopy using hydride generation (HG-AAS), and 2) inductively coupled argon plasma emission spectroscopy using hydride generation (ICP). Samples from 327 cattle were analyzed by HG-AAS, and samples from 344 cattle were analyzed by ICP. The data were examined by linear regression analysis, and the technique of inverse prediction was utilized to determine prediction intervals for estimating blood Se concentration from known serum Se concentration. The correlation coefficients, by simple linear regression of serum Se on blood Se, were 0.79 (r2 = 0.62) and 0.88 (r2 = 0.77) for the HG-AAS data and the ICP data, respectively. For the HG-AAS data, the inverse prediction formula for estimating blood Se when serum Se is known, at the 95% prediction interval, was [formula; see text]. For the ICP data, the inverse prediction formula for estimating blood Se when serum Se is known, at the 95% prediction interval, was [formula; see text]. The prediction intervals were quite wide, and the accuracy of estimating blood Se from a known serum Se was not useful for diagnostic purposes. The use of serum Se concentration to assess nutritional status of cattle with respect to Se does not appear to be appropriate.     

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。