通过饲养防止奶牛酮病和脂肪肝

酮病是由于那些原本被动员起来以满足奶牛生理需要的体脂代谢不完全所引起的。其典型症状包括产奶下降、体重降低和食欲变差,偶尔还出现神经症状。这些症状有时可以清楚地看出(临床状态),但更经常的情况是不能简单地识别(亚临床状态)。     

奶牛发生酮病的饲养因素

酮病是泌乳奶牛常见的营养代谢病,其特征是低血糖和高血酮,持续能量负平衡,严重的会导致高血脂而发生脂肪肝。主要发生在产后2～7星期,多发于饲养管理良好的高产奶牛,且以3～6胎次的高产奶牛发病率较高。在生产实践中,应定期对奶牛尿酮和血酮水平进行监测,更好地控制和预防酮病,减少奶牛场的经济损失。     

奶牛酮病预防之探讨

近年来,我国农村奶牛饲养量不断增多,高产稳产、健康已是奶牛发展的主要目标。在奶牛饲养业中,产乳量的提高,不仅与奶牛的选种选配,提高牛群质量有关;而且与限定性饲养、集约化生产管理有直接关系,限定性饲养和管理又增加了营养代谢病的发病率。在一些地区的农村,...     

奶牛酮病及其防治措施

酮病是高产奶牛常见的代谢性疾病，随着奶牛生产水平的提高，该病的发生率也逐年提高，给生产带来巨大的经济损失。笔者根据酮病的发生情况，从该病的病因、发病机制、临床症状、与其他疾病的关系以及防治等方面对奶牛酮病进行了综述。     

奶牛酮病的研究进展

酮病是泌乳奶牛常见的一种严重的营养代谢病，多发于产犊后10-60天。本病多发于饲养管理良好的高产奶牛，且以3-6胎次的高产母牛发病率较高。调查显示，美国每年有4%-5%的奶牛患临床型酮病（Mary,2000），而加拿大的研究报道，在泌乳期的前9周，奶牛亚临床型酮病的发病率高达59%。在我国高产牛群中，临床酮病的发病率一般占产后母牛的2%-20%，而亚临床型酮病的发病率一般占产后母牛的10%-30%，     

奶牛酮病及其防治措施初探

酮病是高产奶牛常见的代谢性疾病,为此,对酮病的病因、发病机制、临床症状与其他疾病的关系以及防治等方面对该病进行了综述。     

奶牛酮病的诊治与预防

结合多年从事动物疫病诊治的临床经验,对酮病的发病原因、症状、诊断要点、鉴别诊断、治疗、预防等几个方面进行了介绍,希望能给农村奶牛养殖户提供一定的指导。     

奶牛酮病的综合预防和治疗措施

1预防措施烟酸烟酸是抗脂类分解和抗生酮的物质,具有降低体脂分解,降低酮体的能力。给奶牛投喂烟酸后,能调节糖、脂肪代谢有效预防奶牛隐性酮病的发生;据报道,烟酸能抗脂肪分解,能治疗早期泌乳牛酮病;奶牛因分娩可导致烟酸的暂时缺乏,此时补加烟酸可以提高奶牛的采食量并且还具有生糖作用,     

奶牛酮病诊治研究进展

奶牛酮病是高产奶牛产后由于体内碳水化合物及挥发性脂肪酸代谢紊乱所引起的一种全身性功能失调的营养代谢性疾病，可使乳牛的泌乳量下降、乳质降低、繁殖率降低以及引起生殖系统疾病和内分泌紊乱等多种疾病，增加了治疗费用，给奶牛养殖业造成了严重经济损失，文章主要介绍奶牛酮病血液生化诊断指标及防治方法的研究进展。     

奶牛酮病研究进展

奶牛酮病是高产奶牛常见的一种营养代谢性疾病；随着奶牛生产水平的提高，其发病率也呈上升趋势。本文对奶牛酮病的病因、发病机理和临床症状进行了详细地叙述，全面总结了该病的研究现状；并针对其发病机理制定了合理的防治措施，为生产上减少经济损失提供一定的理论指导。     

奶牛亚临床酮病对乳房炎发病情况和抗氧化功能的影响

为研究奶牛亚临床酮病与乳房炎的关系以及血液中的酮体成分对奶牛抗氧化功能的影响,以156头健康荷斯坦奶牛为试验动物（SCC〈200000／mL）,共筛选亚临床酮病奶牛69头（1．0mmol／L≤BHBA〈2．6mmol／L）作为试验组,根据年龄、胎次、产奶量、泌乳天数配对的69头奶牛作为时照组（血液BHBA〈1．0mmol／L）,监测乳房炎发病情况并在各组中选取12头奶牛检测血液酮体水平和抗氧化指标。结果表明亚临床酮病奶牛试验期间乳房炎的发病率为43．48％,对照组试验期间乳房炎的发病率为31．88％,但差异不显著（P〉0．05）;试验组奶牛乳房炎高发期为分娩后3～6周,对照组奶牛乳房炎发病时间为分娩后5～8周,亚临床酮病发病后1～3周内为乳房炎的高发期,占试验组奶牛乳房炎总发病比例的73．33％,试验组和对照组病原菌的组成无显著差异（P〉0．05）;试验组奶牛血液中T—AOC显著低于对照组（P〈0．05）,GSH—PX活力、MDA和N0显著高于对照组（P〈0．05）,血液ACAC浓度与GSH—PX活力呈显著正相关（P〈0．05,r=0．595）,ACAC浓度与NO呈显著正相关（P〈0．05,r=0．655）,T—AOC与MDA呈显著负相关（P〈0．05,r=0．533）。结果表明奶牛亚临床酮病可以导致乳房炎的发病率升高,但不是主要影响因素,亚临床酮病对乳房炎病原体构成无影响;外周血酮体水平升高导致机体总抗氧化能力的降低并引起机体脂质过氧化反应;谷胱甘肽过氧化物酶在发挥抗氧化功能时具有一定的抵抗力和自我调节能力。     

奶牛酮病发病原因及其对生产性能影响调查分析

探索奶牛酮病发病原因、发病规律及其对生产性能的影响,对986头围产期奶牛进行跟踪调查分析。结果表明,奶牛酮病发病率为31.74%,死亡率为4.15%;秋季发病率最高,可达37.4%,其次是冬季和夏季,春季发病率最低;随着胎次、年龄和产乳量的增加,奶牛酮病的发病率明显增高;在第1个泌乳月奶牛酮病的发病率最高,可达50.43%;日粮种类和微量元素越少,奶牛酮病就越容易发生;奶牛发病后受胎率明显降低;发病后产乳量、乳脂率、乳蛋白率、乳糖率和乳干物质比发病前均明显降低,差异显著（P〈0.05）。奶牛酮病发病具有一定的规律性,且可降低奶牛的繁殖性能、产奶量和乳品质。     

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％.     

Mass spectral analysis of urine proteomic profiles of dairy cows suffering from clinical ketosis

Background: Ketosis is an important metabolic disorder in dairy cows during the transition period. The urine proteomics of ketosis has not been investigated using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS).

Objective: The aim is to determine differences between urine proteomic profiles of healthy cows and those with clinical ketosis, and facilitate studies of the underlying physiological and biochemical mechanisms that lead to liver pathology in ketosis.

Animals and methods: We analyzed the urine samples of 20 cows with clinical ketosis (group 1) and 20 control cows (group 2) using SELDI-TOF-MS.

Results: Thirty-nine peptide peaks differed between both groups. Polypeptides corresponding to 26 of these differential peptide peaks were identified using the SWISS-PROT protein database. We found that the peaks of 11 distinct polypeptides from the urine samples of the ketosis group were significantly reduced, compared with those of the control group as based on the Wilcoxon rank sum test. Among these were VGF (non-acronymic) protein, amyloid precursor protein, serum amyloid A (SAA), fibrinogen, C1INH, apolipoprotein C-III, cystatin C, transthyretin, hepcidin, human neutrophil peptides, and osteopontin.

Conclusion: These proteins may represent novel biomarkers of the metabolic changes that occur in dairy cows with ketosis. Our results will help to better understand the physiological changes and pathogenesis observed in cows with ketosis.

Clinical importance: The SELDI-TOF-MS can be used to understand the physiological and biochemical mechanisms of ketosis and identify biomarkers of the disease.     

乳牛产后血浆瘦素动态与亚临床酮病的相关分析

对某奶牛场16头乳牛产前10d至产后56d血样的瘦素、酮体、葡萄糖、脂肪水平及其动态特征和相关性进行了检测。结果表明，血浆瘦素、血酮、血脂含量在不同乳牛和不同时间点之间均有显著差异。酮体在产后14～49d出现高峰，瘦素和血脂从产后第0d到产后第56d内逐渐升高。瘦素水平与血脂水平呈极显著正相关，血酮与血糖呈极显著负相关。亚临床酮病组乳牛的瘦素和血脂水平分别极显著或显著低于血酮正常组，其瘦素、血酮和血糖在试验期内的波动频率明显减少，跨度变长，瘦素在试验期内仅出现一个两端接近0、波峰不超过1．5ng／mL的波。证实，产后乳牛瘦素、血酮、血糖含量的低频率波动变化和产后8周内血浆瘦素跨时持久的单峰动态变化与乳牛亚临床酮病的发生有关。     

Efficacy of controlled-release capsules containing monensin for the prevention of subclinical ketosis in pasture-fed dairy cows

AIMS: To determine the effectiveness of intra-rumenal controlled release capsules (CRC) containing 32?g of monensin administered pre-calving to reduce the cumulative incidence of subclinical ketosis (SCK) in mainly pasture-fed dairy cows.

METHODS: Cows (n=837) due to calve in the first 6 weeks of the spring calving period were enrolled from four commercial herds in the Waikato region of New Zealand in a blinded, randomised, negative-controlled field trial. Three weeks before the start of the calving period cows were randomly allocated to receive either no treatment (control) or a single CRC containing monensin and then blood sampled on two occasions, 7 days apart within 12 days following calving for measurement of concentrations of beta hydroxybutyrate (BHBA) in blood. Cows were diagnosed with SCK if the concentration of BHBA in blood in either of these samples was ≥1.2?mmol/L.

RESULTS: Fewer treated cows were diagnosed with SCK within 12 days post-calving than control cows (144/340 (42.4%) vs. 192/336 (57.1%); p<0.001). There was no interaction between treatment group and age, breed or herd of origin. From the final multivariable model it was estimated that treatment with CRC containing monensin reduced the absolute cumulative incidence of SCK by 17.9 (95% CI=9.2–25.8)% compared to no treatment.

CONCLUSIONS: Treatment with a CRC containing monensin >10 days prior to calving reduced the cumulative incidence of SCK of pasture-based dairy cows in commercial dairy herds within 12 days post-calving.

CLINICAL RELEVANCE: Administration pre-calving of an intra-rumenal bolus containing monensin can be considered as one of a range of management options for the control of SCK in early lactation.     

酮病对泌乳早期乳牛体内代谢和内分泌的影响

随机选取某奶牛场10头患临床酮病乳牛和10头同期健康对照组乳牛，检测了2组乳牛血液10项指标，阐明了酮病对泌乳早期乳牛体内代谢和内分泌的影响。结果显示，酮病乳牛血糖浓度极显著降低（P〈O．01），血浆NEFA和BHBA的浓度明显增高（P〈O．01）；酮病乳牛血浆Ins、LP、NPY、E2的浓度和Ins／Gn比值均明显降低（P〈O．05），而血浆Gn浓度未明显升高，P4未明显降低（P〉0．05）。表明，酮病乳牛体内某些激素协调作用紊乱会妨碍酮病乳牛能量负平衡的缓解，并将对产后生殖机能产生不良影响。     

围产期酮病奶牛血液生化指标特征分析

试验随机选取产前奶牛29头,跟踪采集产前2周、产前1周、分娩当天及产后3,7,14,21 d的血浆样品,检测血浆相关生化指标变化特征,并记录泌乳量。任意采集时间点血浆β-羟丁酸(BHBA)≥1.2 mmol/L则为酮病组, BHBA<1.2 mmol/L则为对照组。结果显示:随机选取的牛群中酮病发病率为58.6%,酮病主要发生在产后7～14 d;酮病组奶牛产前血液相关生化指标与对照组相比无显著性差异;与对照组相比,酮病组奶牛分娩当天血钾水平升高,血磷水平显著降低;产后3 d酮病组奶牛血浆甘油三酯、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、BHBA、泌乳量显著高于对照组奶牛;产后7,14,21 d血浆BHBA、非脂化脂肪酸(ENFA)、TC、HDL-C、低密度脂蛋白胆固醇(LDL-C)水平极显著高于对照组奶牛,血糖水平显著低于对照组奶牛。二元Logistic回归分析显示:产后3 d血液TC、HDL-C、K、BHBA、泌乳量与奶牛酮病的发生显著相关。将显著性相关指标利用Logistic回归建模,最终建立了基于血液HDL-C、BHBA、泌乳量的奶牛酮病早期诊断模型,即y=17.95-9.81×HDL-C-2.71×BHBA-0.20×泌乳量,当y<0时存在发生酮病风险,模型早期预测奶牛酮病的准确率82.8%、灵敏度81.3%、特异性84.6%。     

Use of a hand-held meter for detecting subclinical ketosis in dairy cows

The Optium Xceed is a new hand-held meter for determining blood β-hydroxybutyrate (BHBA) and glucose in human medicine. The objective of this study was to compare BHBA and glucose results obtained using the hand-held meter with those results made with a laboratory method and to evaluate its usefulness as a cowside test in the diagnosis of subclinical ketosis (SCK) in dairy cows. Seventy-eight blood samples from clinically healthy Holstein cows between 5 and 60 days post-calving were analysed. BHBA and glucose values were significantly higher with the hand-held meter versus laboratory methods. Correlation coefficients (r) for BHBA and glucose with the Optium Xceed versus laboratory methods were 0.97 and 0.63, respectively. Based on Bland–Altman plot and Passing–Bablok regression, agreement between two methods was good for BHBA but the agreement for glucose was only fair. When SCK was defined as plasma BHBA levels 1200 μmol/L, the sensitivity and specificity of the hand-held meter ketone testing in determining SCK were 85% and 94%, respectively. Raising the threshold of the laboratory method to 1400 μmol/L, the sensitivity and specificity incremented to 0.90 and 0.98, respectively.In conclusion, the blood ketone-monitoring device can be used as a rapid and reliable diagnostic test to detect SCK under field conditions.