Evaluation of an electronic device used as a quick screening method to detect changes in the red cell content of the blood in horses participating in endurance trail rides     

A. De Waal  F. J. Potgieter 《Veterinary research communications》1991,15(4):309-314

Dehydration, to varying degrees, will inevitably occur in horses participating in endurance trail rides. This water loss is directly related to the amount of body water lost through evaporative cooling, that in turn being related to the amount and rate of work performed, and to the environmental temperature and humidity.An electronic apparatus that can substitute for the conventional and time-consuming venous haematocrit was developed to measure the animals' hydration status. The mechanism of this electrometer is based upon the relationship between the red cell content and the electrical conductivity of the blood. The electrometer reading gave a significant correlation (p<0.001) with the venous haematocrit, thus indicating that the electrometer is a reliable apparatus for determining the animals' hydration status within seconds of venepuncture.  相似文献   

Effect of feed deprivation on daily water consumption in healthy horses     

David E. Freeman  Alexandra Mooney  Steeve Giguère  Jami Claire  Chloe Evetts  Patricia Diskant 《Equine veterinary journal》2021,53(1):117-124

  相似文献   

Suspected levamisole intoxication in calves     

KR Müller  C Dwyer 《New Zealand veterinary journal》2016,64(4):257-260

CASE HISTORY: A group of 32 Friesian and four Hereford calves, 3–4 months old with body weights between 100–120?kg, were purchased from a weaner sale. On arrival at the property the Hereford calves were treated with a combination anthelmintic containing 2?g/L abamectin and 80?g/L levamisole hydrochloride. Shortly afterwards they developed tremors and frothing from the mouth, and two died overnight. The Friesian calves were treated with the same anthelmintic on the following day, when some showed hypersalivation and frothing from the mouth.

CLINICAL FINDINGS: Examination of the three most severely affected Friesian calves revealed severe nicotinic-type symptoms including hypersalivation, frothing from the mouth, muscle tremors, recumbency, rapid respiration, hyperaesthesia, and central nervous system depression. Other calves showed mild to moderate signs of intoxication including restlessness, tail switching, salivation, tremors, frequent defaecation, mild colic and jaw chomping. Two calves died shortly afterwards. An adverse drug event investigation revealed that the formulation and quality of the anthelmintic was within the correct specification, and that the drench gun was functioning correctly.

DIAGNOSIS: Suspected levamisole intoxication due to a combination of possible overdosing, dehydration, and stress caused by transportation and prolonged yarding.

CLINICAL RELEVANCE: Susceptibility to levamisole toxicity in New Zealand calves can be increased if factors like dehydration or stress are present. Levamisole has a narrow margin of safety, and overdosing in calves can easily occur if the dose rate is not based on their actual weight or health status.  相似文献   

玉米果穗不同部位子粒水分动态差异研究     

李红燕  李璐璐  王永宏  赵如浪  张文杰  明博  王克如  谢瑞芝  侯鹏  张万旭  刘万茂  薛军  李少昆 《玉米科学》2020,28(5):102-109

为明确玉米果穗不同部位子粒含水率和脱水速率的动态变化差异,在春玉米区宁夏银川和夏玉米区河南新乡采用8个不同熟期和脱水速率的品种,将玉米果穗垂直等分为5个部位,定期测定不同部位子粒含水率,计算子粒脱水速率。结果表明,玉米生长中后期,果穗上部子粒含水率低于中下部子粒含水率,生理成熟前各部位子粒含水率的差值低于生理成熟后。参试品种生理成熟前20 d时不同部位子粒含水率极差低于3%,成熟期的极差值变幅为0.6%～5.2%,生理成熟后极差最大值可达6.2%。同一果穗自上而下子粒的脱水速率逐渐降低,品种之间有明显差异,先玉335、迪卡517和迪卡519果穗不同部位子粒脱水速率差异较大。果穗中部子粒脱水速率和平均脱水速率与不同部位子粒含水率的极差值呈负相关。  相似文献   

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia     

D. Kami  L. Shi  T. Sato  T. Suzuki  K. Oosawa 《Scientia Horticulturae》2009

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.  相似文献   

快速脱水抑制葡萄干制过程中膜脂过氧化及褐变   总被引：1，自引：1，他引：1  

刘峰娟  孟阳  白羽嘉  刘春月  黄文书  冯作山 《农业工程学报》2014,30(17):285-294

为探索脱水速度对无核白葡萄干制过程中膜脂过氧化作用及褐变的影响,以新疆无核白葡萄为试验材料,经过葡萄促干剂处理后,采用快速脱水和缓慢脱水2种处理,质量每减轻10%进行取样,测定脱水过程中果实干基含水率、干燥速率、褐变度、细胞膜透性、丙二醛(malonaldehyde,MDA)含量、脂氧合酶(lipoxygenase,LOX)、超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)、多酚氧化酶(polyphenol oxidase,PPO)活性以及总酚含量的变化。结果表明:与缓慢脱水相比,快速脱水处理显著(P0.05)降低了无核白葡萄褐变度的上升,减少MDA生成量以及膜透性的增加,抑制LOX活性的升高,保持较高的活性氧清除酶SOD、CAT及POD活性及较高的总酚含量,且使PPO活性保持在一个较低的水平。因此认为,快速脱水可以有效地抑制无核白葡萄的膜脂过氧化作用对细胞膜的破坏,保持细胞的完整性,且PPO活性较低,从而减少无核白葡萄脱水褐变的发生。研究结果为快速脱水在无核白葡萄干制中的应用提供参考。  相似文献   

切片番木瓜糖溶液渗透脱水的影响因素分析     

林启训  傅坤仁 《福建农林大学学报(自然科学版)》2000,29(1):110-114

用二次回归正交组合试验方案探讨了切片厚度、浸泡溶液质量分数和渗透时间对番木瓜 (Carica pa-paga L.)糖溶液渗透脱水的影响 .结果表明 :影响切片番木瓜糖溶液的主次因素顺序是切片厚度二次作用、渗透时间、溶液质量分数与渗透时间交互、渗透时间二次作用、料液比、切片厚度、切片厚度与渗透时间交互、渗透时间二次作用、浸泡溶液质量分数 ;影响可溶性固形物白利糖度的主次因素顺序是渗透时间、浸泡溶液质量分数、溶液质量分数与渗透时间交互、渗透时间二次作用、溶液质量分数与切片厚度交互、料液比、切片厚度 .建立了不同渗透脱水条件下的番木瓜失重率和可溶性固形物白利糖度的回归方程 .t检验表明 ,2个回归方程达 0 .0 1显著水平 ,剩余标准差分别为 1.70和 1.33,可用于实际生产的预测和控制  相似文献   

石化污泥脱水工艺优化研究     

杨瑞洪  刘丹 《安徽农业科学》2010,38(30):17015-17016

[目的]确定污泥最佳絮凝剂种类及其最佳的投加量和脱水工艺参数。[方法]针对石化企业污泥脱水工艺中存在的问题,以污泥沉降性能、污泥比阻和滤饼含水率为指标筛选出最佳絮凝剂,并通过正交试验对污泥脱水工艺进行优化。[结果]各因素对滤饼含水率的影响顺序为：搅拌水平〉投加量〉抽滤压力〉絮凝剂。最佳操作条件为絮凝剂K6728投加量2．0ml;搅拌水平150r／min 10s,50r／min 10min：过滤压力0．05MPa。各因素对污泥比阻的影响顺序为：搅拌水平〉抽滤压力〉投加量〉絮凝剂。最佳操作条件为絮凝剂K6728投加量2．5ml;搅拌水平150r／min 10s,50r／min 10min;过滤压力0．03MPa。综合分析得出最佳工艺参数为：K6728絮凝剂投加量2．0ml;搅拌水平150r／min 10s,50r／min 10min;过滤压力0．03MPa。此时,污泥脱水效果最佳。[结论]优化了石化污泥脱水工艺。  相似文献   

辽河流域玉米籽粒脱水特点及适宜收获期分析   总被引：1，自引：0，他引：1  

黄兆福  明博  王克如  谢瑞芝  杨飞  王志刚  肖春华  李少昆 《作物学报》2019,45(6):922-931

辽河流域处于中国东北春玉米区南部,积温资源相对丰富,在该区域推广玉米机械粒收技术具有较好的热量资源基础,但区域内玉米收获时籽粒含水率偏高,机械粒收的破碎率、损失率偏高等质量问题突出。分析区域内主推品种的籽粒脱水特征、基于热量资源条件确定机械粒收的适宜时间,是解决上述问题的合理途径。2017年选择该区域主推的29个不同熟期玉米品种,在开鲁县和铁岭县开展了籽粒脱水动态观测试验。结合流域内常年春玉米播种日期、不同品种生长发育及籽粒脱水积温需求、历史气象数据等分析结果,建立不同品种在辽河流域适宜机械粒收时期的预测方法。结果显示, Logistic Power模型可以很好地模拟春玉米籽粒含水率变化过程。不同品种籽粒实收含水率与模拟含水率间存在极显著的线性关系,决定系数R2为0.916 (n=45),均方根误差RMSE为1.217。研究建立的不同品种籽粒含水率模型具有极佳的区域适用性,以2017年国审的4个宜机收品种及流域内2个主栽品种研究,明确了不同品种适宜机械粒收时期的分布规律。国审品种中,德育919和京农科728自播种至籽粒含水率降至25%活动积温需求低于3200°C d,在辽河流域大部地区可于9月中下旬达到高质量机械粒收的籽粒含水率要求。泽玉8911和吉单66积温需求低于3400°C d,可于10月上中旬在流域内实现机械粒收,较上述德育919和京农科728晚10～20d。而当地主栽的辽单575和京科968脱水至适宜籽粒含水率的积温需求较泽玉8911和吉单66多200°Cd,无法在当地常规收获期实现高质量的机械粒收。本研究检验了基于LogisticPower模型的籽粒含水率预测模型在区域分析应用中的精度。通过比较国审宜机收品种与当地主栽品种的籽粒含水率变化、成熟和脱水的积温需求以及适宜机械粒收日期的空间分布规律,更新现有品种有助于在辽河流域实现常规收获期内的高质量机械粒收。  相似文献   

Differential Responses of Electrolyte Leakage and Pigment Compositions in Maize and Sorghum After Exposure to and Recovery from Pre-and Post-Flowering Dehydration     

Abuhay Takele 《中国农业科学(英文版)》2010,9(6):813-824

Drought stress is often the most limiting factor to maize and sorghum production in the semi-arid areas.This study evaluates the response of electrolyte leakage,chlorophyll,carotenoid and anthocyanin contents in maize （cv.Melkassa-2 and sorghum cv.Macia） after exposure to and recovery from pre- and post-flowering dehydration in plants grown in a controlled environment growth chamber under constant environmental conditions （12/12 h day/night,28-32/17°C day/night temperature,60-80% RH and PPFD of 1 200-1 400 μmol m-2 s-1）,at the Department of Botany,University of Cape Town,South Africa.It was revealed that dehydration induced increases in electrolyte leakage was observed in both species during both pre- and post-flowering stages.Electrolyte leakage was however,higher during post- than pre-flowering dehydration in both species.Dehydration during both pre- and post-flowering stages caused a decrease in chlorophyll and carotenoid contents in both maize and sorghum.Chlorophyll and carotenoid contents of both pre- and post-flowering dehydrated sorghum was markedly higher than that of maize throughout the duration of the dehydration period.As opposed to chlorophyll and carotenoid contents,anthocyanin contents increased during pre- and post-flowering dehydration in both species.Differences were however,observed between both species in the response of anthocyanin content to pre- and post-flowering dehydration.Full recovery of chlorophyll,carotenoid and anthocyanin contents were observed in those plants rehydrated during pre-flowering stages.There was however,no recovery in both species during post-flowering rehydration.This study should help understand some adaptive mechanisms developed by maize and sorghum during the dehydration and rehydration periods and contribute to identify useful traits for breeding programs.  相似文献