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。     

围产期奶牛亚临床酮病的生化诊断

本研究分析比较了产后初期亚临床酮病奶牛和健康奶牛血清葡萄糖、非酯化脂肪酸、-羟丁酸、铜和锌的代谢水平,以期进一步完善奶牛亚临床酮病的生化诊断。结果表明,与健康奶牛相比较,亚临床酮病奶牛的血清非酯化脂肪酸和-羟丁酸含量显著升高,而葡萄糖和锌含量显著降低,铜含量无显著差异。揭示血清葡萄糖、非酯化脂肪酸和锌含量可作为奶牛亚临床酮病生化诊断的参考指标。     

DHI酮病模块监测奶牛酮病的研究

奶牛酮病是危害奶牛健康的主要代谢性疾病之一,通过测定牛乳中丙酮和β-羟丁酸的含量可以对奶牛健康状况进行评估和筛查。对云南4家DHI参测牧场的酮体测定数据进行分析。根据Foss公司推荐的判断标准,4个牧场亚临床酮病平均发生率为6.1%,范围在3.3%~9.4%,临床型酮病发生率为0.7%,范围在0.4%~1.8%。Ⅰ牧场亚临床型酮病5.2%,临床型酮病1.8%;Ⅱ牧场亚临床型酮病4.7%,临床型酮病0.4%;Ⅲ牧场亚临床型酮病9.4%,临床型酮病0.7%;Ⅳ牧场亚临床型酮病3.3%,临床型酮病0.6%。利用DHI检测数据的酮病预警功能,对奶牛及时跟踪排查,对其进行早期干预,可有效减少酮病的发生。     

高产奶牛亚临床酮病的诊断与防治

一、奶牛亚临床酮病的产生研究表明,患有亚临床酮病的牛只每天要比非酮病牛的产奶量减少1到10 L不等,一旦开始泌乳,高产奶牛的亚临床酮病的发病率大约是40%,而临床型酮病的发病率仅为5%。由于亚临床酮病不容易被发觉,所以往往在牧场的日常管理中遭到忽视。一头患有亚临床酮病牛所带来的损失约为78美元,而且在此情况下增加了奶牛患有临床酮病及皱胃扭转,胎衣不下等疾病的概率。酮病病因涉及的因素很广,且     

奶牛亚临床酮病发病率与泌乳天数、胎次及体况的关系

探究亚临床酮病发病率与奶牛泌乳天数、胎次及体况的关系。选取7个规模化奶牛场的493头临床状况健康荷斯坦奶牛进行检测,采用全血中β-羟丁酸(BHBA)≥1.2 mmol/L作为亚临床酮病的标准。研究发现,奶牛亚临床酮病发病率为1.5%~62.5%,不同牧场之间发病率差异很大,亚临床酮病高发期为奶牛产犊后1个月内,高发胎次为3胎及以上,高发牛群的体况评分在3.5及以上。牧场应该提高饲料品质和改善产后护理来确保奶牛达到理想体况,降低奶牛亚临床酮病发病率,减少经济损失。     

亚临床酮病对泌乳早期奶牛繁殖性能的影响

为探究围产期亚临床酮病与泌乳奶牛繁殖性能及卵泡发育之间的关系,本试验选择了黑龙江省某大型集约化牛场开展试验,根据产后血酮水平确定亚临床酮病组和健康组奶牛共80头,该牛场亚临床酮病发生率为71%;两组奶牛跟踪到产后50 d进行直肠检查和B超检查了解卵泡发育状况,并记录繁殖性能数据。结果显示:与健康组奶牛相比,亚临床酮病组奶牛产后首次发情天数延长10 d,产后60 d内发情次数少0.58次;产后50 d子宫复旧不全高15%,与亚临床酮病呈显著正相关(R^2=8.74);产后60 d卵泡直径小3 mm(P<0.05)。结论:该牛场奶牛亚临床酮病发病率较高,是引起奶牛产后繁殖障碍的风险因素,也是造成卵泡发育受阻的不良因素,会导致奶牛繁殖力下降。     

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。     

规模化奶牛场亚临床酮病的调查与防治

2018年7月-2019年6月,笔者对本区域12个规模化奶牛场1054头奶牛进行亚临床酮病的调查,先后采集尿液、乳液2122份,临床使用尿酮试剂带、粉剂法等试剂进行测试,了解垦区奶牛亚临床酮病(隐性酮病)的发病情况。试验结果显示:亚临床酮病的阳性率平均为17.46%;奶牛产后21~40 d阳性率最高,占发病率的51.14%;二胎以上发病率占45.70%,8 t以上产奶量奶牛发病率占36.89%。     

亚临床酮病奶牛的氧化抗氧化状态和乳品质

为研究亚临床酮病奶牛的氧化应激状态及其对奶牛乳品质的影响,分别选取21头亚临床酮病奶牛和21头健康奶牛,通过尾静脉采集非抗凝血,用于氧化抗氧化指标的检测;同时收集新鲜乳样,用于乳成分的检测。结果表明,与健康奶牛相比,亚临床酮病奶牛的总抗氧化能力、谷胱甘肽过氧化物酶、乳蛋白和总固形物活性、血清葡萄糖显著或极显著降低(P<0.05;P<0.01),乳脂肪比、非酯化脂肪酸、β-羟基丁酸、丙二醛含量显著或极显著升高(P<0.05;P<0.01)。由此可见,亚临床酮病奶牛体内存在氧化应激,主要抗氧化酶活性降低,并且氧化应激状态显著高于健康奶牛,乳品质低于健康奶牛。     

奶牛酮病致病机理及诊治方法研究进展

奶牛酮病又称为奶牛醋酮血症,是高产奶牛产后因碳水化合物和挥发性脂肪酸代谢障碍所引起的疾病,根据其有无临床表现可分为临床型酮病和亚临床型酮病。临床型酮病主要表现为食欲降低,奶产量减少,体况消瘦,血酮、乳酮以及尿酮含量异常升高,     

基于DHI数据浅谈石河子地区奶牛酮病发病情况及预防措施

为了解石河子地区奶牛酮病的发病情况,以新疆生产建设兵团第八师畜牧兽医工作站DHI中心具有一定代表性的八个参测牛场的泌乳奶牛作为研究对象,每个牛场随机抽取体况相近的泌乳牛100头,通过测定奶样中丙酮和β-羟丁酸的含量,对该地区奶牛酮病发病情况进行初步统计分析,并提出相应的预防措施。结果显示,临床型酮病的总发病率为8.75%,亚临床型酮病总发病率为45.63%。该结果可能与牛场的饲养管理水平有一定的关系;由于亚临床型酮病发病率普遍较高,且具有一定的潜伏期,因此,牛场需要加强对酮病的监测,从而达到及时治疗和预防酮病的目的。     

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.     

Relationship between ketosis and dairy cows’ blood metabolites in intensive production farms of the periurban area of Dakar

This study which involved 140 Holstein and Montbeliard was carried out in the periurban area of Dakar with the aim to establish the relationship between ketosis, milk production and biochemical blood metabolites. The results showed that ketosis is a real problem in periurban farms around the city of Dakar with high proportions of 33.57% for subclinical ketosis and 6.43% for clinical ketosis. In their second month of milking, cows with subclinical ketosis had a decrease of 12.4 and 15.,6% in milk yield respectively for Montbeliard and Holstein, whereas cows with clinical ketosis had a decrease of 18.6 and 26%. Ketogenic cows (subclinical and clinical) have significantly lower average levels of blood glucose (p<0.05) and significantly higher average levels of blood urea (p<0.05) than cows with normal blood beta-Hydroxy Butyrate (BbHB) levels. Also, from one farm to another, significant difference was recorded with concentration of total proteins and globulin, calcium and magnesium.     

Subclinical ketosis in lactating dairy cattle.

Subclinical ketosis is an important and common condition of early-lactation dairy cattle. It is associated with losses in milk production and increased risk of periparturient disease. Prevention depends on several factors, including proper transition-cow nutrition, management of body condition, and the use of certain feed additives such as niacin, propylene glycol, and ionophores. All currently available cowside tests for subclinical ketosis have certain limitations in their use. Effective monitoring schemes for subclinical ketosis can be developed, however, and these may be useful in many herd health programs.     

Metabolic aspects in the etiology of displaced abomasum.

Results of studies on metabolic variables that exist prior to the diagnosis of displaced abomasum (DA) indicate that subclinical ketosis is a risk factor for DA. Serum aspartate aminotransferase activity, serum and milk betahydroxybutyric acid concentrations, and milk fat-to-protein ratios were often elevated before the diagnosis of DA, and these variables may be used to predict DA. Prevention of subclinical ketosis may prevent DA.     

Peripartum back fat thickness of multiparous Holstein-Friesian cows with displacement of the abomasum or ketosis

To establish a method to predict postpartum diseases using prepartum back fat thickness (BFT), the peripartum BFTs of 54 healthy multiparous cows before calving, which were diagnosed with postpartum displacement of the abomasum (DA), clinical ketosis or subclinical ketosis were compared with those of healthy cows from 8 weeks before the expected calving date to 8 weeks after calving. The peripartum BFTs of the cows with DA or clinical ketosis were significantly higher than those of healthy cows. The peripartum BFTs of the cows with subclinical ketosis were not significantly higher than those of the healthy cows.     

亚临床酮病奶牛血清中微量元素代谢水平的研究

本试验旨在研究荷斯坦奶牛亚临床酮病对血清中微量元素的影响,选择40头产后1～15 d的荷斯坦亚临床酮病奶牛,通过应用原子吸收光谱法测定血清中Cu、Fe、Mn、Zn、Se、Co含量,应用分光光度计和比色法测定血清中GSH-Px、T-AOC、T-SOD活力及MDA含量。结果显示,阳性组血清中Cu、Zn、Se、Co的含量在整个检测过程中均极显著低于对照组(P＜0.01);阳性组血清中Mn的含量在第1、5天的检测中显著低于对照组(P＜0.05),第10、15天极显著低于对照组(P＜0.01);阳性组血清中Fe的含量与对照组相比差异不显著（P＞0.05）;阳性组血清中GSH-Px、T-SOD、T-AOC的活性均极显著低于对照组(P＜0.01);阳性组血清中MDA的含量极显著高于对照组(P＜0.01)。结果表明,亚临床酮病直接影响奶牛抗氧化系统GSH-Px、T-AOC、T-SOD的活性,间接地影响血清中微量元素Cu、Mn、Se、Zn的含量。Co是维生素B₁₂的重要组成部分,维生素B₁₂在肝脏内的浓度下降,从而导致亚临床酮病血清中Co的含量降低。亚临床酮病奶牛肝脏和氧化酶受损,破坏Fe的结合,机体内贮存的Fe则可以释放出来,维持机体的需要,血清中Fe的含量没有显著的变化。     

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.