Effect of Parenteral Selenium Administration to Sheep on Prevalence and Recovery from Footrot

Background: Insufficient intake of selenium (Se) is common in many regions, and can contribute to increased susceptibility to and prolonged recovery from infectious diseases. Objective: To determine the effect of Se administration in decreasing the severity and prevalence of footrot in sheep. Animals: Thirty‐eight footrot‐affected and 19 nonaffected sheep from a commercial flock of known high incidence of footrot. Methods: Placebo‐controlled, prospective, 15‐month clinical trial. Footrot‐affected sheep were randomly assigned into 2 groups (n = 19) and injected with either 5 mg Se (footrot [FR]‐Se) or saline (FR‐Sal) at 1‐month intervals for the duration of the study. Unaffected sheep (controls) received no treatment. Sheep feet were examined, trimmed, and scored for footrot with a scale of 0 (no footrot) to 4 (extensive) at 0, 3, 6, 9, and 15 months. Sheep were also bled at time 0 and then at 3, 6, and 15 months to assess whole blood Se concentrations. Results: At time 0, control sheep (255 ± 11 ng/mL) had higher (P < .05) whole blood Se concentrations compared with FR‐Se (205 ± 12 ng/mL) and FR‐Sal (211 ± 14 ng/mL) sheep. By 6 months, FR‐Se sheep (317 ± 9 ng/mL) had whole blood Se concentrations greater (P < .05) than both control (281 ± 14 ng/mL) and FR‐Sal (277 ± 16 ng/mL) sheep. FR‐Se ewes showed a faster decline in highest lesion score at 3 (P= .012) and 6 (P= .0036) months, and a greater decrease in the number of feet with foot score >0 at 6 (P= .020) months compared with FR‐Sal ewes. Sheep with blood Se concentrations <300 ng/mL were at 3.5 times greater risk (1.1–12.1 confidence interval, odds ratio) for FR, although this relationship was only significant (P= .04) at 6 months of the study. Conclusions and Clinical Importance: In sheep with footrot, improved Se status in conjunction with routine control practices result in more rapid improvement of foot lesions.     

Comparison of the fast‐induced and high dietary zinc‐induced molting: trace elements dynamic in serum and eggs at different production stages in hens (Gallus domesticus)

A number of 252, 70 week old, single comb white leghorn hens at the end of their first production cycle were divided into two groups: group‐I; molted by fasting and group‐II; by high dietary zinc to obtain the second and third production cycle. Sampling was carried out at 5%, peak and end of the second production cycle and at 5% and peak of the third production cycle. Serum zinc decreased at the peak of the second production cycle, while increased at the 5% of the third production cycle in zinc‐molted group. Serum copper and manganese increased at the 5% and peak of the second production cycle in zinc‐molted group. Egg albumin zinc and copper increased at the 5% and peak of the second as well as third production cycles in zinc‐molted group. Egg albumin manganese increased at 5% during the second production cycle in fasting molted group. Egg yolk zinc increased at the peak of the second production cycle in zinc‐molted group. Egg yolk copper increased at the 5% of second production cycle but decreased during the third production cycle in zinc‐molted group. Egg yolk manganese increased at the 5% and at the end of the second production cycle in zinc molted group. Egg yolk manganese and iron decreased during the third production cycle in zinc‐molted group. Eggshell zinc decreased at the end of the second production cycle in the zinc‐molted group, while eggshell copper increased at the peak of the second as well as third production cycles in fasting molted group.     

The relationship between serum level of thyroid hormones,trace elements and antioxidant enzymes in dromedary camel (<Emphasis Type="Italic">Camelus dromedarius</Emphasis>)

Thyroid hormones might be able to regulate the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX). The role of thyroid hormones in metabolic pathways and antioxidant enzyme activities are well known in many species. Nevertheless, there is no report describing probable relationship between thyroid hormones status, erythrocyte antioxidant enzymes and serum profiles of trace elements. This study was undertaken to investigate the relationship between these parameters in Iranian dromedary camels. Blood samples were taken from the jugular vein of 30 clinically healthy Iranian dromedary camels under aseptic conditions during 6 consecutive days of summer. The serum was analyzed for serum profile of thyroid hormones, trace elements, SOD and GPX activity. There were no significant differences in serum thyroid hormones, serum level of zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), selenium and antioxidant enzymes in different days (P > 0.05). There was a significant negative correlation between SOD and Fe (P < 0.01, r = -493). There was no significant correlation between other parameters. In case of copper deficiency likewise the present study, the copper was used to produce more SOD, so there was a decrease in Fe transportation, and it might be a cause of decrease in Fe amount. On the other hand, a relatively small quantity of Fe is present in tissue myoglobin, catalase, peroxidases, and cytochromes. So it might be another cause of decrease in Fe amount. The explanation for these finding is not possible at this moment and further investigations are needed to interpret these changes.     

微量元素在反刍动物生产中的应用

微量元素在反刍动物体内发挥着重要作用,作者阐述了微量元素在反刍动物体内的营养作用,以及其对反刍动物生产性能、繁殖性能和瘤胃微生物的影响。为合理补饲微量元素、调控瘤胃发酵、提高生产性能和繁殖性能提供参考依据。     

藏药牦牛骨主要矿物质元素的主因子分析

用因子分析法对藏药牦牛骨4个部位的12种微量元素测定数据进行了多因素分析.结果表明:2个主因子能合理解释这些微量元素之间的相关关系,从而达到压缩原变量的目的.     

屠前停用矿物质添加剂对猪生长性能、胴体品质和粪中矿物质排泄量的影响

屠前停用日粮中矿物质添加剂不影响猪的生长性能、胴体品质,同时还可降低饲料成本,减少粪中矿物质元素的排泄量,降低对环境的污染,是一安全、环保、节本增效的饲养技术.主要综述了这一技术的研究结果,为该技术应用推广提供参考.     

脐橙品质与自然土壤中稀土元素相关性分析

在赣南稀土高背景区和稀土低背景区不同地质环境脐橙果园分别取岩石、土壤、脐橙植物样24组,用ICP-MS法测定其中15种稀土元素的含量;检测脐橙果实有机营养物质总糖、总酸、粗纤维、维生素C、类胡萝卜素、氨基酸等含量,并对稀土元素在土壤和脐橙植物体内的含量与脐橙有机营养物质含量的相关性进行了研究。结果表明,稀土高背景区脐橙稀土含量非常低,而各项有机营养物质指标均略高于稀土低背景区脐橙,表明稀土元素有益于脐橙有机营养物质的形成和提高;通过相关性分析和通径分析,表明稀土中与脐橙有机营养物质相关程度最高的是轻稀土元素Pr、La、Nd、Ce。     

基于缺素试验的甘蔗专用肥三要素参数及配方研究——以广西桂中蔗区为例

进行N、P、K缺素试验,测算出三要素土壤原料蔗生产能力hm2分别为64065kg、71280kg、69690kg,根据广西旱地甘蔗模式施肥公式,计算出针对该蔗区目标产量达到90000kghm-2时,N、P2O5、K2O三要素吸收参数-hm2分别为226.91kg、181.55kg、181.42kg,根据GB15063-2001复混肥料技术标准,初步设计针对该蔗区甘蔗专用肥配方养分总量为26%,N、P2O5、K2O=10:8:8。依此配方生产样肥在该蔗区进行肥效验证,比对照增产、增糖分别为21.54%、0.78%(绝对值)。确定针对桂中部分蔗区的甘蔗专用肥配方,提供生产企业进行产业化生产与推广应用。     

Significance of fruit transpiration on calcium nutrition in developing apricot fruit

The first objective of this study was to search for a possible correlation between accumulation of calcium (Ca), potassium (K), and magnesium (Mg) and fruit transpiration in developing apricot (Prunus armeniaca L.) fruit. Secondly, the work aimed to determine the significance of transpirational flux on Ca nutrition. We hypothesized that if the fruit transpiration is the determining factor of Ca accumulation (phloem‐immobile element) then the import of Ca would be suppressed by restriction of fruit water loss, while the import of phloem‐mobile nutrients (i.e., K and Mg) would not be. To test this hypothesis, the seasonal changes of transpiration and of Ca, K, and Mg concentration/accumulation were assessed in fruits left to naturally transpire or under restricted transpiration (bagged fruits). Fruit transpiration was measured on detached fruits using a portable gas‐exchange equipment (ADC‐LCA4, ADC BioScientific Ltd, Hoddesdon, England). Results demonstrated that 83% of total fruit Ca content was gained within the first 4 weeks after fruit‐set, and that Ca import ceased concomitantly to a reduction of transpiration. In spite of the limitation of fruit transpiration, Ca entered the nontranspiring fruits, and its concentration was about 45% of that in control fruits suggesting that other factor(s) operated for Ca accumulation. This study provides the evidence that fruit transpiration accounted for 55% of total Ca that entered a fruit. We conclude that optimal soil Ca availability and apportioning to the fruit during the early 4 weeks of growth are essential to sustain the fruit demand of this nutrient and that some cultural practices (e.g., summer pruning, irrigation) should be tested as possible tools to improve fruit Ca nutrition via increasing fruit transpiration.     

基于RS和GIS扎龙湿地景观时空演变研究

以RS、GIS技术手段,1995年、2000年和2004年LandsatTM遥感数据为主要数据源,分析研究区域景观结构、主要景观要素的时空演变、景观组分变化和转移过程,并定性分析景观动态变化特征和驱动机制。结果表明:研究区域呈现以沼泽地景观为基质的草地景观、耕地景观等相对为主体的交错湿地景观格局;沼泽湿地景观、水域景观、耕地景观、草地景观等在转移过程中保持较大的保留率;草地→沼泽地和沼泽地→草地是研究区域的主要景观类型的优势转移过程,处于主导地位,草地→盐碱地,自然因素为该景观类型的转变及区域生态环境恶化的重要原因,盐碱地→草地,反映出土地利用动态变化驱动机制的复杂性;对土地的利用一般应按照一定的规划原则进行,做到土地的合理利用,实现土地资源的永续利用和区域可持续发展。