奶牛醋酮血症最佳检测方法的筛选

本试验选取90头规模化奶牛场产后0~28d奶牛,采用酮粉法与TNN型奶牛血酮测试仪相结合的方法,调查规模化奶牛场奶牛醋酮血症的发病情况,并以TNN型奶牛血酮测试仪BHBA含量大于1.2mmol/L作为醋酮血症奶牛的诊断标准,采用酮粉法分别对尿、乳和血样品进行检测,并将定性检测的结果与定量检测的结果相比较。结果表明,血酮仪检测β-羟丁酸测得的阳性率为18.89%,与此结果相比较,符合率最高的是酮粉法测血酮,符合率为96.18%;其次是酮粉法测乳酮,符合率为92.47%;酮粉法检测尿酮与乳酮、血酮相比较差异极显著(P0.01);检测尿酮与乳酮结果差异显著不(P0.05)。假阳性率最低的方法是用酮粉法测血酮,假阳性率为9.08%,酮粉法测乳酮为21.06%,而假阳性率最高的是酮粉法测尿酮,为48.56%。从假阳性率分析3种检测方法差异极显著(P0.01)。几种方法中漏检率最低的是酮粉法测乳酮,漏检率为9.11%;其次为酮粉法测尿酮,漏检率为9.18%;漏检率最高的方法是试酮粉法测血酮,漏检率为17.96%。酮粉法测血酮与测尿酮乳酮相比漏检率差异极显著(P0.01)。     

奶牛亚临床酮病检测

本研究采用试纸条法、紫外分光光度法和酮粉法检测奶牛亚临床酮病,结果表明：以紫外分光光度法定量检测结果为诊断标准,试纸条法具有较高的敏感性和特异性,分别为69％和94％,酮粉法的检测敏感性和特异性较低,分别为56％和90％.     

酮粉法检测泌乳牛尿酮乳酮的应用研究

荷斯坦泌乳牛尿、乳酮体的酮粉法定性试验表明：尿酮阳性率为29．25％，乳酮阳性率为10％。尿、乳阳性牛的血酮、血糖、乳酮、尿酮定量测定表明：酮粉法判定泌乳奶牛亚临床酮病，尿酮阳性反应具有早期、敏感、准确性低的特点。乳酮阳性反应具有准确、敏感性低、方便等特点。二者同时定性检测具有互补作用。     

布鲁氏菌抗体检测试纸条的研制和初步比较

本试验利用胶体金免疫层析技术原理,研制了布鲁氏菌抗体检测试纸条,并以布鲁氏菌阳性血清国家标准品进行了敏感性试验,确定了最低检出量,同时与有可能存在交叉反应的血清和阴性血清进行了特异性试验;然后将保存不同时间的试纸条在进行了敏感性和特异性试验,证明其稳定期可以达到15个月。选择临床牛羊血清30份,利用该试纸条与布鲁氏菌病虎红平板试验抗原进行同步检测,发现两种试剂的检测符合率为98%。试验证明,所研制的布鲁氏菌抗体检测试纸条敏感性高、特异性强、稳定期长。     

两种定性检测方法对围产期奶牛亚临床酮病的检测结果比较

采用酮粉法和试剂法检测贵南县两个奶牛场135头临床健康的围产期奶牛的尿酮和乳酮,结果表明,试剂法和酮粉法均可用于早期检测尿中酮体,临床上以粉剂法更佳;奶牛酮病的早期诊断应在产后10d左右开始,尿酮阳性率高而敏感,而乳酮阳性率低;尿酮阳性率集中在产后20d。     

乌兰察布市泌乳奶牛亚临床酮病的调查研究

试验选取内蒙古乌兰察布市489头泌乳奶牛,通过对尿中和乳中酮体采用酮粉法检测进行奶牛亚临床酮病的监测与分析。结果表明,乌兰察布市泌乳奶牛亚临床酮病发病率为10.63%;第1和第2个泌乳月亚临床酮病发病率明显高于第3个及以上泌乳月;各胎次亚临床酮病发病率以3～5胎最高;日产奶量在30kg以上亚临床酮病发病率显著高于日产奶量在30kg以下奶牛;养殖小区以及规模户饲养奶牛的亚临床酮病发生率较高。     

奶牛疾病防治专题讲座(十四) 酮病

酮病是由于碳水化合物、脂肪代谢障碍致使血糖含量减少,而血酮含量异常增多,在临床上以消化机能、神经系统紊乱等为特征的营养代谢性疾病。在临床上不显示任何症状,只是血酮含量增多的酮血病,尿酮含量增多的酮尿病和乳酮含量增多的酮乳病等,对这类酮病统称为亚临床酮病。一、病     

3种国产布病抗体检测试剂盒的效果评价

为了比较国产布鲁菌病间接ELISA抗体检测试剂盒、竞争ELISA抗体检测试剂盒和胶体金试纸条的检测效果,通过对已知阴阳性血清样品的检测,比较了上述3种检测方法的敏感性和特异性。进一步采用临床血清样品比较了3种检测方法与虎红平板凝集试验(RBT)的检测效果,并采用补体结合试验(CFT)对结果进行了复核。结果显示,间接ELISA、竞争ELISA和胶体金试纸条的敏感性分别为96.67%,100.00%和98.33%,3种检测方法的特异性分别为98.33%,93.33%和93.33%。对300份临床样品的检测结果显示,4种检测方法共同检出的阳性样本为27份,阴性样品为210份,整体符合率为79%。通过CFT对63份不同方法检验结果有差异的样本进行确诊,结果表明RBT与CFT的符合率最低,仅为3.17%;间接ELISA与CFT的符合率最高,为98.41%;竞争ELISA和胶体金试纸条的符合率分别为87.30%,85.71%。结果表明,间接ELISA、竞争ELISA和胶体金试纸条具有良好的特异性和敏感性,能够满足布病临床检测需求;RBT对临床样本的检测存在较高比例假阳性和假阴性。     

定性检测荷斯坦奶牛围产期和泌乳期尿酮、乳酮的变化规律

通过对围产期奶牛和泌乳奶牛尿和乳中酮体抽样检查 ,选择对酮病做出早期诊断的最佳时间和方法。为此将年龄在 4～ 1 0岁 ,胎次在 2～ 7胎的围产期 45头奶牛按产前和产后的天数不同分为 9个小组 ,每组 5头牛 ,1组为产前 1 5d,2组为产前 1 0 d,3组为产前 5d,4组为产前 1～ 2 d,5组为产后 1～ 2 d,6组为产后 5d,7组为产后 1 0 d,8组为产后 1 5d,9组为产后 2 0d。应用酮粉法和试剂法检测各组牛尿和乳中酮体含量 ,同时应用酮粉法检测泌乳牛尿样 1 0 6份和乳样 70份。结果表明 :试剂法和酮粉法均可用于早期检测尿中酮体 ,临床上以粉剂法更佳 ;奶牛酮病的早期诊断应在产后 1 0 d左右开始 ,尿酮阳性率高而敏感 ,乳酮阳性率低而准确 ;尿酮阳性率集中在产后 6 0 d和 1 2 0～ 1 80 d,尤其产后 2 0 d乳酮阳性明显     

用试剂法检测围产期奶牛亚临床酮病的发病规律研究

[目的]为了探讨奶牛围产期亚临床酮病的发病规律.[方法]采用试剂法检测斜沟乡上窑村94头临床健康的围产期奶牛的尿酮和乳酮.[结果]表明:试剂法可用于早期检测尿中酮体,奶牛酮病的早期诊断在产后10 d左右开始,尿酮阳性率高而敏感.[结论]尿酮阳性率集中在产后20 d内.     

新疆昌吉州围产期奶牛酮病流行病学调查及其对生产性能影响

为了掌握新疆昌吉州围产期奶牛酮病的流行现状,研究该病对奶牛生产性能的影响,采集昌吉州1 898 份围产期奶牛血液进行血酮检测,统计分析酮病和亚临床酮病的发生率,比较健康奶牛、亚临床酮病奶牛、酮病奶牛在产奶量、乳品质、免疫力指标方面的差异。结果昌吉州围产期奶牛酮病、亚临床酮病发生率分别为10.06%和33.09%;酮病奶牛、亚临床酮病奶牛与健康奶牛相比,平均日产奶量分别降低14.39%（P<0.05）、5.26%（P<0.05）,乳脂率分别降低11.99%（P<0.05）、6.0%（P<0.05）,乳糖率分别降低6.14%（P<0.05）、2.18%（P>0.05）,乳蛋白率分别降低11.88%（P<0.05）、5.80%（P<0.05）,体细胞数分别提高26.72%（P<0.05）、16.29%（P<0.05）,IgA含量分别降低23.81%（P<0.05）、9.52%（P>0.05）,IgG含量分别降低15.71%（P<0.05）、7.33%（P<0.05）,IgM含量分别降低14.58%（P<0.05）、6.25%（P<0.05）。结论昌吉州围产期奶牛均存在酮病和亚临床酮病的发生,并能够使奶牛的产奶量、乳品质和免疫力降低。     

Subclinical ketosis: prevalence and associations with production and disease.

Cows in 32 southern Ontario Holstein herds were monitored for subclinical ketosis for a period of two and one half years. Milk samples were routinely collected and the level of milk ketone bodies determined by the use of a commercial nitroprusside based test powder (reactions scored as negative, +1 or +2). Approximately 92% of positive reactions were observed in the first 65 days of lactation and for that time period the prevalence of ketosis was 12.1%. Based on this prevalence, the minimum possible duration of subclinical ketosis would be 7.9 days and the minimum possible lactational incidence rate would be 12.1%. The prevalence during the first 65 days of lactation in individual herds ranged from 0 to 33.9%. Subclinical ketosis was more likely to be found in cows experiencing metritis than in unaffected cows. Detection of elevated levels of milk ketones also indicated that the cow had a significantly higher risk of having clinical ketosis, metritis or cystic ovaries diagnosed within the following four days. Milk ketone scores of +1 and +2 were found to be associated with a reduction in daily milk production of 1.0 and 1.4 kg of milk respectively.     

Suppression of interferon response of bovine leukocytes during clinical and subclinical ketosis in lactating cows.

The influence of spontaneous ketosis on interferon alpha and gamma production in blood leucocytes and on PHA induced lymphocyte blastogenic response was investigated. Twenty three cows 4.13 +/- 2.8 weeks after calving were divided into three experimental groups on the basis of blood ketone bodies, glucose and free fatty acids concentrations. The leukocytes of cows with clinical symptoms and the highest concentration of ketones and free fatty acids in blood responded with the lowest levels of interferons alpha and gamma to three interferon inducers: Newcastle Disease Virus (NDV), phytohemagglutinin (PHA) and concanavalin A (ConA). Depression in interferon PHA stimulated synthesis correlated with a very low mitogenic response of blood lymphocytes. Blood leukocytes of cows with subclinical ketosis, characterized by mild clinical symptoms and a lower concentration of ketones in blood in comparison to cows with clinical ketosis, responded better to interferon and mitogenic stimulation; however, the interferon titer and blastogenesis were still lower than in leukocytes of healthy cows. Correlation between the stage of ketosis and the level of interferon production in milk leukocytes was also observed. A possible relationship between the suppression of interferon production in blood leukocytes and the increased concentration of ketone bodies in blood is discussed.     

Evaluation of two cowside tests for the detection of subclinical ketosis in dairy cows.

The goal of this study was to evaluate the sensitivity and specificity of two cowside tests for subclinical ketosis in dairy cows. The tests utilize milk and urine samples, respectively. One hundred and eighty-five cows, one to sixty days postpartum, were sampled for milk, urine, and blood. Subclinical ketosis was defined with serum beta-hydroxybutyrate measurements. The sensitivity and the specificity of both tests at different beta-hydroxybutyrate levels were estimated. When subclinical ketosis was defined at beta-hydroxybutyrate levels of 1.4 mmol/L and higher, the milk test had sensitivity of 90% and specificity of 96%. The urine test lacked specificity (values < 67%), but sensitivity was 100% at beta-hydroxybutyrate levels of 1.4 mmol/L upward. Both the milk and urine test can be used to monitor subclinical ketosis in a herd. Milk testing is preferred, because of the easy obtainability of milk combined with the overall better test characteristics.     

泌乳奶牛脂肪肝早期诊断的研究

为了寻找泌乳奶牛脂肪肝早期诊断方法,本研究从某千头奶牛场随机选取了30头乳酮阳性的奶牛,其中临床酮病牛10头,亚临床酮病牛20头,测定其肝脂含量以及血中代谢指标和肝功指标。试验结果表明,脂肪肝的奶牛存在能量负平衡现象,机体呈现高游离脂肪酸血症、高酮血症,肝脂浸润越重,能量代谢障碍越严重;乳酮阳性出现时间的早晚与脂肪肝的严重程度密切相关,乳酮阳性产后出现的越早,乳酮阳性越明显,肝脂浸润越重;随肝脂浸润程度的加重,肝功多个指标会出现异常,重度的脂肪肝会引发肝功能不全。本试验证明,酮粉法可以作为早期诊断奶牛脂肪肝的初选方法,肝功指标异常可作为诊断脂肪肝的辅助方法,两者结合可作为奶牛脂肪肝的实用、有效和准确的早期诊断方法,准确率可达80%。     

Subclinical ketosis in dairy cows

Subclinical ketosis is defined as a preclinical stage of ketosis. The peak prevalence of subclinical ketosis occurs during the fourth week of lactation. Herd-related factors, breed, parity, and season are other important determinants. Subclinical ketosis can be revealed by determining levels of plasma glucose, plasma NEFA and blood, and milk or urine ketone body concentration. There are theoretical and practical advantages of using milk ketone bodies. Most authors are agreed on approximate lower and upper borderlines for subclinical ketosis. The risk of an outbreak of clinical symptoms has been evaluated by some authors. Most authors have found significant negative relationships between energy balance and ketone body concentration. Some disagreement may be attributable to the fact that the diets used in different experiments can have different glucogenic potential, even if the energy content is the same. This affects the relationship between energy balance and ketone body concentration, as the ketone body level is influenced by both the energy balance and plasma glucose. Feeding silage with high butyric acid content increases the risk of subclinical ketosis. There are indications that cows with the highest milk yield directly after calving are at greatest risk for developing ketosis. Increased ketone body level secondarily reduces milk production, a decrease that has been quantified by some authors. Subclinical ketosis causes delayed reproductive functions return to normal after calving, increased intervals from calving to first and last service, and an increased frequency of ovarian cysts. The routine determination of milk acetone levels in control programs can be used to evaluate the status of individual cows, to indicate the energy feeding in early lactation at a herd level, and to evaluate sires for breeding. The heritability and the tendency toward a positive genetic correlation between milk acetone and milk yield have also been discussed, as have aspects of nutritional prevention. Factors such as energy- and protein-rich roughage, tasty high-energy concentrates, suitable feeding during the dry period, and division of the concentrates into at least four meals are considered to be important.