Selenium supplementation of young red deer (Cervus elaphus)

Abstract

Two selenium (Se) supplementation trials were conducted in successive years involving a total of 70 red deer calves 3–15 months of age grazing pasture containing 30–57 ppb of Se on a dry matter basis. The trials compared growth rate, whole blood Se and glutathione peroxidase (GSHpx) concentrations of calves which received periodic doses of oral Se or a single injection of barium selenate (equivalent to 50 mg Se) or no Se supplementation. There were no significant weight gain differences between treated and untreated groups in either trial. Whole blood GSHpx levels were strongly correlated with blood Se levels (r = 0.9278) and produced the following regression equation: GSHpx 0.0155 Se ? 2.292.

In both years the 3 month old calves had GSHpx levels of 6–9 kU/l which probably derived from maternal transfer of Se. The GSHpx levels in unsupplemented calves declined from these levels to a minimum in winter (group means ? 2.6) and then progressively rose the following spring and summer.

Periodical oral dosing with Se or a single injection of barium selenate significantly elevated blood Se and GSHpx levels throughout the trials.     

Selenium supplementation of young red deer (Cervus elaphus)

Two selenium (Se) supplementation trials were conducted in successive years involving a total of 70 red deer calves 3-15 months of age grazing pasture containing 30-57 ppb of Se on a dry matter basis. The trials compared growth rate, whole blood Se and glutathione peroxidase (GSHpx) concentrations of calves which received periodic doses of oral Se or a single injection of barium selenate (equivalent to 50 mg Se) or no Se supplementation. There were no significant weight gain differences between treated and untreated groups in either trial. Whole blood GSHpx levels were strongly correlated with blood Se levels (r = 0.9278) and produced the following regression equation: GSHpx = 0.0155 Se - 2.292. In both years the 3 month old calves had GSHpx levels of 6-9 kU/I which probably derived from maternal transfer of Se. The GSHpx levels in unsupplemented calves declined from these levels to a minimum in winter (group means approximately 2.6) and then progressively rose the following spring and summer. Periodical oral dosing with Se or a single injection of barium selenate significantly elevated blood Se and GSHpx levels throughout the trials.     

Selenium supplementation of sheep by topdressing pastures under high rainfall conditions

Two 4 hectare paddocks on a property in a high rainfall area of South Westland were topdressed with two different formulations of selenium (Se) prills at a rate of 1 kg/ha. Whole blood Se and glutathione peroxidase (GPx) concentrations were recorded at monthly intervals in four groups of adult Perendale ewes. These consisted of two groups of 25 set-stocked on each of these paddocks, the main mob of ewes which ranged over the rest of the farm and received routine oral administration of Se, and a group of 25 untreated control ewes running with the main mob. Blood Se and GPx concentrations in the two groups receiving prills showed a large increase over pre-treatment levels at the first monthly sampling after application of the prills, and remained significantly higher than the concentrations recorded for the main group and the untreated controls for 12 months. Pasture Se concentrations in the treated paddocks showed an initial peak at 1 month, but had declined to a level similar to control pastures by 6 months. At no stage did any of the blood values for Se iu the treatment groups approach toxic levels. In contrast, the main mob were given 5 mg of Se (orally combined with an anthelmintic drench twice per year), but in each case blood Se and GPx values only rose slightly above those of the untreated controls and quickly returned to similar concentrations.     

添加硒对氧化应激仔猪抗氧化能力和组织细胞超微结构的影响

本试验采用已建立的氧化应激模型,进一步研究添加硒对氧化应激仔猪抗氧化能力和组织细胞超微结构的影响。试验采用2×3＋1因子试验设计,84头（26±2）d断奶仔猪随机分配到7个处理中,每个处理6个重复,每个重复2头猪。检测血清抗氧化酶活力、MDA含量和组织细胞超微结构。结果发现：与非应激组相比,氧化应激引起血清抗氧化酶活力降低和MDA含量上升,肝脏和脾脏发生细胞凋亡;对应激试猪,随着硒添加水平的升高,氧化损伤的程度减弱。表现为GSH、GPx、SOD和CAT活性提高,MDA降低,细胞结构损伤减弱。当硒添加量上升到0.6mg/kg时,其抗氧化酶活力可达到与非应激组差异不显著的水平。结果表明,氧化应激会降低机体抗氧化能力,损伤细胞结构,补充硒有助于维持机体氧化还原稳衡动态的正常,减轻细胞的过氧化损伤;在本试验条件下,在氧化应激仔猪日粮中添加0.6mg/kg硒可获得较好的抗应激效应。     

Selenium supplementation affects broiler growth performance, meat yield and feather coverage

(1) Selenium (Se) is an essential part of numerous selenoproteins, most of which are involved in the antioxidant system of the body. It is also required by poultry for the maintenance of optimal health and meat quality. This paper reports data from a study examining the effect of dietary source and concentration of selenium on broiler performance and meat quality. (2) Increased dietary selenium content markedly reduced feed conversion ratio (FCR) as a result of significantly lower feed intakes of birds while maintaining the same weight gains. (3) Selenium supplementation increased feathering, with organic selenium (selenised yeast) being superior to inorganic selenium (sodium selenite). (4) Birds receiving organic selenium in their diets had improved eviscerated weight, breast yield and reduced drip loss. (5) There were significant concentration x source interactions on yields of breasts and marylands (thigh plus drumstick), with elevated levels of organic selenium increasing the yields, whereas the opposite was true for the inorganic selenium.     

Selenium supplementation in lambs: effects on antibody responses to a salmonella vaccine

In trials conducted in 1984 and 1985, the effects of selenium injections on the antibody responses of lambs marginally deficient in selenium to Salmonella dublin were assessed. Control lambs (mean glutathione peroxidase [GSHPx] less than 20 iu/ml) responded well to the vaccine. No difference was observed in the antibody titres of animals treated twice with 5 mg selenium as sodium selenate. During the following season animals given 50 mg selenium as barium selenate showed slightly higher titres than controls. The results show that marginally selenium deficient lambs are able to elicit strong antibody titres to a bacterial antigen and that supplementation with selenium produces, at best, a marginal enhancement of the responses observed.     

Selenium levels of beef cattle in southeastern british columbia relative to supplementation and type of pasture

Moderate to extremely low levels of selenium in hay were related to marginally deficient levels of selenium in sera from cattle in the Windermere Valley of southeastern British Columbia. Deficiency was most pronounced in cattle fed local hay during the winter or grazed on fertilized/irrigated pastures. Cattle on range had adequate levels of serum selenium. When sodium selenite was fed at 1.0 and 3.5 mg per head per day, serum selenium levels increased commensurate with the dose. Clinical observations indicated that a variety of clinical problems disappeared after injection or supplementation with selenium/vitamin E.     

Selenium supplementation and selenium status of dairy cows fed diets based on grass, grass silage or maize silage

In three separate trial series (TS) the effect of diet composition on selenium (Se) status of dairy cows were investigated. Diets were formulated based mainly on grass (TS1), grass silage (TS2) or maize silage (TS3) with different levels of Se supplementation. Each TS comprised a total of 30 dairy cows and contained one treatment group without Se supplementation (control) and two groups with increasing levels of Se supplementation (levels 1 and 2). Selenium was administered as Na-selenite. The control groups of the different TS showed a very low Se supply of 38–54 μg Se/kg DM. At level 1 the Se supply was increased to 102–165 μg Se/kg DM and at level 2 was 294–373 μg Se/kg DM. After completion of the 6-week trials the average plasma Se concentration of the control cows (without Se supplementation) across all TS was 21.5 μg/l; this increased significantly following Se supplementation, to 37.7 μg/l at level 1 and 61.5 μg/l at level 2. The plasma glutathione peroxidase (GSH-Px) activity of the control cows averaged 67 U/l, rising considerably after supplementation at level 1 to a value of 101 U/l, but showed little further increase at level 2 with a mean value of 120 U/l. By contrast, the average Se content of the milk was unchanged in the control and level 1 groups at 10.5 μg/kg and 10.9 μg/kg, respectively, and only increased markedly after supplementation at level 2 to a mean value of 15.1 μg/kg. The diet based on maize silage, while having a similar Se content as the grass and grass silage-based diets, resulted in a slightly improved Se status, which is due to a higher Se intake from soybean meal.     

Selenium deficiency

Calvings in a herd infected by Brucella abortus were monitored by cultural examination of milk and mucus and by serological and cultural examination of 5 ml samples of the blood. Out of 129 samples from which culture of B abortus was attempted, only one yielded a positive result.     

硒与生殖

硒是机体所必需的微量元素 ,不仅在抗氧化防御系统中有显著作用 ,在动物和人的生育力方面亦起着基本作用。硒是提高动物繁殖力和生产力的重要物质。在雄性动物和人 ,硒是精子必需的矿物元素之一 ,缺硒会导致精子活力下降 ,线粒体发育与形态异常 ,活精子数减少。对缺硒的雄性动物和人 ,适量补充硒有利于提高精子活力。但高浓度硒对精子的形成及其运动性会产生毒副作用。在雌性动物 ,硒对生育有无特异性影响 ,尚未定论 ,对硒不充足的母羊和猪适量补硒 ,可增加其生育力、生殖器的重量和体积、仔畜的成活率和初生重。在母牛 ,补硒对其繁殖力的影响有两种不同的观点 ;在母马 ,补硒对其生殖似无影响 ;对于家禽 ,硒是保持正常高产蛋率和高孵化率所必需的