牛奶酸碱度与奶牛隐性乳房炎发病情况的相关研究

采集100头商丘市成年中国荷斯坦奶牛的乳样300份,根据奶牛的年龄胎次等情况将之分成3组。利用酸度计、光学显微镜并辅以计数板辅助测定牛乳的pH值及体细胞的含量,分析奶牛隐性乳房炎与牛乳pH值的相关关系。结果表明当牛乳的体细胞在20万／毫升时,奶牛乳房炎发病率为0.3％,其乳汁的pH值在6.4～6.6之间;体细胞在20万～50万／毫升区间时,奶牛乳房炎发病率为11.2％,奶牛乳汁pH值在6,6～6,8之间;体细胞在50万～150万／毫升区间时,奶牛乳房炎发病率为26.1％,奶牛乳汁pH值在6.8～7.0之间;体细胞在150万～500 万／毫升区间时,奶牛乳房炎发病率为45.3％,奶牛乳汁pH值在7.0～7.2之间;体细胞大于500万／毫升时,奶牛乳房炎发病率为68.7％。奶牛乳汁pH值在7.2以上。牛乳pH值的变化与体细胞和炎性细胞的含量呈显著的正相关,相关系数r=0,387。     

牛奶酸碱度与奶牛隐性乳房炎发病情况的相关研究

采集100头商丘市成年中国荷斯坦奶牛的乳样300份,根据奶牛的年龄胎次等情况将之分成3组.利用酸度计、光学显微镜并辅以计数板辅助测定牛乳的pH值及体细胞的含量,分析奶牛隐性乳房炎与牛乳pH值的相关关系.结果表明当牛乳的体细胞在20万/毫升时,奶牛乳房炎发病率为0,3%,其乳汁的pH值在6.4～6.6之间:体细胞在20万～50万/毫升区间时,奶牛乳房炎发病率为11.2%,奶牛乳汁pH值在6.6～6.8之间:体细胞在50万～150万/毫升区间时,奶牛乳房炎发病率为26.1%,奶牛乳汁pH值在6.8～7.0之间;体细胞在150万～500 万/毫升区间时,奶牛乳房炎发病率为45.3%,奶牛乳汁pH值在7.0～7.2之间;体细胞大于500万/毫升时,奶牛乳房炎发病率为68.7%,奶牛乳汁pH值在7.2以上.牛乳pH值的变化与体细胞和炎性细胞的含量呈显著的正相关,相关系数r=0.387.     

乳头液体保护膜对预防奶牛乳房炎效果的评价

奶牛乳头液体保护膜是一种预防奶牛乳房炎的新型乳头药浴消毒剂,主要用于挤奶后的奶牛乳房药浴。为评价其预防奶牛乳房炎的临床效果,本试验以泌乳期奶牛为研究对象,进行奶牛乳头液体保护膜预防奶牛乳房炎的研究,结果显示,奶牛乳头液体保护膜对奶牛乳汁中的乳脂、乳蛋白、乳糖及乳汁p H值、比重、日均泌乳量几乎没有影响,而且能很好地降低牛奶中的体细胞数,是一种更适合于进行临床防治奶牛隐性乳房炎的新型药浴夜。     

奶牛隐性乳房炎简易诊断方法的探讨

隐性乳房炎是奶牛常发病之一,不仅使牛奶质量下降、保存期短、而且严重影响奶牛的生产力。因此对隐性乳房炎的及时诊断与防治是奶牛生产上的重大课题之一。目前对隐性乳房炎的检测方法很多,如检查牛体细胞,这种方法虽然准确率高,但主要应用于实验室,不易在广大农村推广。最近几年应用乳房炎诊断液进行牛旁快速诊断,这种方法诊断迅速,但生     

利用体细胞计数监控乳房炎

乳房炎是造成奶牛业损失最大的疾病,随着奶牛业与乳品工业的发展及人类对公共卫生的重视,奶牛乳房炎的危害已引起人们的极大关注。但是由于97％的乳房炎属于隐性乳房炎,因此奶牛生产者并不十分清楚牛群乳房的实际健康状况和因此而造成的奶量损失,所以一个能提供牛群实际健康状况的监测系统就显得特别重要,DHI的体细胞计数就具有这种功能。体细胞数是反映乳房健康状况的重要标志。根据体细胞计数的高低很容易确定乳房炎发病情况,并能进一步估算出牛奶损失。本文通过探讨体细胞数与乳房炎及奶损失之间的关系,寻求监控乳房炎的有效方…     

奶牛隐性乳房炎的几种检测方法

隐性乳房炎是奶牛乳房炎的1种,在临床中发病率较高,给奶牛生产带来巨大的经济损失.因其无临床症状,所以在临床中难以发现,只能借助辅助检查才能诊断.目前,检测奶牛隐性乳房炎的方法主要有乳汁病原微生物检测法、乳汁体细胞检测法、化学检测法和物理学检测法等,具体介绍如下.     

乳头液体保护膜“乳宁散”预防奶牛乳房炎效果评价

为观察乳头液体保护膜对奶牛隐性乳房炎的预防效果,选择隐性乳房炎奶牛60头,随机分为5组,每组12头。试验I组为对照组;II组为4%次氯酸钠组;III组为0.5%洗必泰组;IV组为1%碘伏组;V组为奶牛乳头液体保护膜浸组。在0、30、60、90 d采用SCC法和CMT法检测牛乳中体细胞数并记录临床型奶牛乳房炎发病数和发病率,同时记录各组奶牛泌乳总量和平均泌乳量。结果表明：同对照组相比,各试验组均能显著降低隐性乳房炎病牛体细胞数,且对奶牛乳脂、乳蛋白、乳糖及乳汁pH值、比重、日均泌乳量几乎没有影响。用于预防奶牛隐性乳房炎时,试验III、V的效果高于试验II、IV组,差异显著（P〈0.05）。在进行奶牛隐性乳房炎临床治疗试验时,试验V组对隐性乳房炎的治愈率和有效率分别为77.78%和88.89%,远远高于其他各组。说明奶牛乳头液体保护膜是一种更适合于进行临床防治奶牛隐性乳房炎的新型奶牛药浴药物,对临床型奶牛乳房炎有较好的预防效果,可以作为预防类药物用于奶牛生产中,降低奶牛乳房炎的发生率。     

乳头药浴涂膜剂对奶牛乳房炎的临床疗效

为观察乳头药浴涂膜剂对奶牛隐性乳房炎的预防效果,选择隐性乳房炎奶牛60头,随机分为5组,每组12头。试验Ⅰ组为对照组,Ⅱ组为4%次氯酸钠组,Ⅲ组为0.5%洗必泰组,Ⅳ组为1%碘伏组,Ⅴ组为药浴涂膜剂浸组。在第0、30、60、90天采用SCC法和CMT法检测牛乳中体细胞数,并记录临床型奶牛乳房炎的发病数和发病率,同时记录各组奶牛泌乳总量和平均泌乳量。结果:同对照组相比,各试验组均能显著降低隐性乳房炎病牛体细胞数,且对奶牛乳脂、乳蛋白、乳糖及乳汁p H值、比重、日均泌乳量几乎没有影响。用于预防奶牛隐性乳房炎时,试验Ⅲ、Ⅴ的效果高于试验Ⅱ、Ⅳ组,差异显著(P0.05)。在进行奶牛隐性乳房炎临床治疗试验时,试验Ⅴ组对隐性乳房炎的治愈率和有效率分别为77.78%、88.89%,远高于其他各组。结论:奶牛乳头药浴涂膜剂是一种更适合于进行临床防治奶牛隐性乳房炎的新型奶牛药浴药物,对临床型奶牛乳房炎有较好的预防效果,可以作为预防类药物用于奶牛生产中,降低奶牛乳房炎的发生率。     

北京地区奶牛隐性乳房炎发生情况调查报告

采用体细胞计数法、BMT法对北京地区多个大型奶牛场及养殖小区进行奶牛隐性乳房炎的检测,结果表明,奶牛隐性乳房炎头数阳性率,2007年和2008年分别为54.08%、32.03%,乳区阳性率分别为25.90%、11.94%,北京地区奶牛隐形乳房炎发生率呈明显下降趋势。     

牛博士~奶牛乳房安全卫士对预防奶牛乳房炎效果的研究

本文将60头健康泌乳奶牛分为2组,每组各30头,分别使用牛博士奶牛乳房安全卫士和常规药浴液对挤奶后的奶牛乳头进行消毒,计算2种方式消毒后的乳房干燥时间、体细胞数平均值和方差以及牛博士奶牛乳房安全卫士使用瓶数。结果表明:牛博士奶牛乳房安全卫士具有降低体细胞数,预防奶牛乳房炎的作用;可代替常规药浴,对奶牛乳房进行挤奶后消毒,具有快速干燥,保持乳房清洁干燥和防冻伤的作用;且一瓶牛博士奶牛乳房安全卫士可供300头奶牛使用,性价比高。     

Preliminary studies on the prevalence of Mycoplasma bovis mastitis in dairy in cattle in Australia

A highly sensitive and specific PCR (MB-PCR) was used in preliminary studies to detect M. bovis in milk samples to investigate its association with high somatic cell count (SCC), an indicator of subclinical mastitis and one of the factors in down grading the quality of milk. A total of 186 and 167 herds were tested with 43% and 62% of herds positive for M. bovis in Victoria and North Queensland, respectively. The quarter milks from 52 cows with persistently high SCC were tested by MB-PCR and culture to investigate the association of M. bovis with major mastitis pathogens (MMP). M. Bovis was detected in 77% of cows of which 19% alone had M. bovis without any other bacteria, 17% had M. bovis in combination with major mastitis pathogens and 40% had M. bovis in combination with non-major mastitis pathogens. We believe that M. bovis is widespread in dairy cattle and has the potential to produce disease alone or to predispose the udder to disease caused by major mastitis and environmental pathogens. These studies have revealed a hitherto unrecognised high prevalence of M. bovis in dairy cattle in North Queensland and Victoria in Australia. These initial studies also give a clear association between M. bovis and elevated somatic cell counts.     

Novel SNPs in IL-17F and IL-17A genes associated with somatic cell count in Chinese Holstein and Inner-Mongolia Sanhe cattle

Background: Bovine mastitis is the most common and costly disease of lactating cattle worldwide. Apart from milk somatic cell count(SCC) and somatic cell score(SCS), serum cytokines such as interleukin-17(IL-17) and interleukin-4(IL-4) may also be potential indicators for bovine mastitis. The present study was designed to investigate the effects of single nucleotide polymorphisms(SNPs) in bovine IL-17 F and IL-17 A genes on SCC, SCS and serum cytokines in Chinese Holstein and Inner-Mongolia Sanhe cattle, and to compare the m RNA expression variations of the cows with different genotypes.Results: A total of 464 lactating cows(337 Holstein and 127 Inner-Mongolia Sanhe cattle) were screened for SNPs identification and the data were analyzed using fixed effects of herd, parity, season and year of calving by general linear model procedure. The results revealed that SNP g.24392436 C T in IL-17 F and SNP g.24345410 A G in IL-17 A showed significant effects on SCC and IL-4 in Holstein(n = 337) and on IL-17 and IL-4 in Sanhe cattle(n = 127). The homozygous GG genotype of SNP g.24345410 A G had significantly higher m RNA expression compared with the heterozygous AG genotype.Conclusions: The results indicate that IL-17 F and IL-17 A could be powerful candidate genes of mastitis resistance and the significant SNPs might be useful genetic markers against mastitis in both dairy and dual purpose cattle.     

牛乳体细胞数对牛奶品质的影响

随着奶牛业和乳品业的迅速发展,牛奶体细胞数在牛奶生产中的重要作用越来越得到人们的重视。本文综述了影响牛奶体细胞数的因素、体细胞数在奶牛生产中的应用及其对乳及乳制品品质的影响。     

髓过氧化物酶检测奶牛隐性乳房炎研究进展

奶牛隐性乳房炎的检测方法有多种,相比之下,近年来,国外报道的用检测奶样中髓过氧化物酶(myeloperoxidase,MPO)来诊断奶牛隐性乳房炎的方法更符合快速、简便、高灵敏度、高特异性的现代诊断方法要求。根据乳房炎过程中的生理生化指标的变化特点,可得出奶液中MPO是乳房炎指示物。奶样中的体细胞数(SCC)和MPO浓度的相关系数值为0.91,奶样中随着SCC的增高,MPO的水平也增高达到2 000 ng/mL,同时也可分离到大量细菌。免疫学分析MPO单克隆抗体与奶液中成分乳铁蛋白、乳过氧化物酶、牛血清白蛋白、MPO、淋巴细胞、少量体细胞的乳样之间ELISA反应没有交叉性,表明MPO分子在乳房炎中具有很高的特异性。通过对牛奶中MPO的检测来判断乳房内中性粒细胞(PMN)的活性状态,可对奶牛隐性乳房炎做出早期诊断。     

Prevalence of Mastitis and Brucellosis in Cattle in Awassa and the Peri‐Urban Areas of Two Smaller Towns

The prevalence of mastitis and brucellosis in urban and peri‐urban settings was studied in Awassa and two smaller nearby towns in southern Ethiopia, because milk‐born diseases are causing a risk for human health, besides direct impacts on animal production. Mastitis was investigated by examining 80 cows (320 udder quarters) using California mastitis test (CMT) and somatic cell count (SCC). The prevalence of brucellosis was assessed by sampling 177 cattle in Awassa and its peri‐urban areas using serological methods. Logistic regression was used to analyse risk factors associated with mastitis. Prevalence of clinical mastitis on quarter level was 0.9%, and 1.9% of quarters were non‐functional or blocked. Prevalence of sub‐clinical mastitis at quarter level in urban and peri‐urban areas was significantly different (P < 0.05). Cows in large herds and at advanced lactation number were associated with higher risk of infection. The percentage of quarters positive on CMT (42.5%) was close to the percentage‐positive detected by SCC (41.2%). Prevalence of brucellosis was 3.9% in the peri‐urban area, while no brucellosis cases were detected in Awassa. More frequent use of artificial insemination in the urban than in peri‐urban area might have contributed to the absence of brucellosis in the urban location. The extent of mastitis is, however, a threat to the dairy enterprise in and around Awassa. Pasteurization of milk and milk products is indicated in some parts of the area because of the danger of brucellosis.     

On distinguishing cause and consequence: do high somatic cell counts lead to lower milk yield or does high milk yield lead to lower somatic cell count?

Researchers have reported that as milk yield increases composite milk somatic cell count (SCC) is diluted in cattle with no intramammary infection (IMI) and as a consequence, estimates of SCC from high yields are lower than estimates of SCC from low yields in dairy cows without an IMI. To date, estimates of reduced milk yield associated with high SCC because of intramammary infection have not been adjusted for any dilution of SCC. Ignoring dilution is therefore likely to lead to an overestimate of reduction in yield with increasing SCC. This paper investigates scenarios of the possible impact of dilution and inflammation on the association between somatic cell count and yield. The data used to investigate this relationship come from 8373 monthly records of milk yield and composite somatic cell count, together with incidence of clinical mastitis, which were recorded on 850 cows from five dairy cattle farms in Gloucestershire, UK. Two sets of models were used to investigate dilution and inflammation using two-level hierarchical models. The first set of models was used to estimate the linear (dilution) and log10-linear (inflammation) impact of SCC on the outcome variable milk yield. Five general linear models with increasing inclusion of higher test day SCC values were run. The cumulative categories were test day SCC values of up to and inclusive of 30, 50, 100, 200 and 400x10(3)cells/ml. Linear and log linear SCC influences on milk yield were estimated. At low SCC values the linear SCC predictor was dominant, while at higher values the log linear predictor was dominant. Up to 100x10(3)cells/ml there was mostly a slightly negative linear relationship between SCC and yield, potentially indicating a dilution effect. In the second set of models, three approaches to adjust milk loss for dilution were compared with an unadjusted model. In general, dilution-adjusted SCC values fitted the data better and resulted in a slightly lower milk loss per SCC category compared with unadjusted SCC. In all models with a dilution term there was a significant reduction in yield with SCC>200x10(3)cells/ml.     

奶牛隐性乳房炎的调查分析

采用体细胞计数(SCC)法对杨凌某奶牛场中60头不同胎次和泌乳时间奶牛隐性乳房炎进行检测,对引起乳房炎的可能诱因进行调查分析,研究该场奶牛隐性乳房炎的发病规律,为本病的防控提供参考。结果表明,受检奶牛隐性乳房炎的检出率为43.3%。1胎～2胎奶牛隐性乳房炎检出率为40.0%,3胎～4胎为46.7%,隐性乳房炎的检出率有随胎次增加而升高的趋势;泌乳时间少于200 d的泌乳牛隐性乳房炎检出率为27.6%,200 d～300 d的为36.4%,300 d～400 d的为41.7%,超过400 d的为50.0%,提示奶牛隐性乳房炎有随泌乳期升高的趋势。本调查显示,奶牛隐性乳房炎的发生与胎次和泌乳时间有显著的相关性,饲养管理和卫生条件是乳房炎发生的重要诱因。     

芽孢杆菌、乳酸菌复合菌制剂对奶牛泌乳性能和乳汁中体细胞的影响研究

为研究芽孢杆菌、乳酸菌复合菌制剂即奶牛专用微生态制剂对奶牛生产奶性能及乳中体细胞数的影响,选择45头荷斯坦奶牛,随机分为3组,每组15头,进行为期60 d天的饲养试验,3组的基础日粮相同,1、2组分别添加0.5%、1%的奶牛专用微生态制剂,3组为对照.分析了各组的产奶量、乳脂率及体细胞数.结果表明:试验组1、2奶牛产奶量分别比对照组提高10.83%,14.28%,差异均极显著(P＜0.01);试验组1、2牛奶的乳脂率分别比对照组提高0.27%、0.34%,差异极显著(P＜0.01);试验1、2组奶中体细胞数比对照组分别低0.21%、0.26%,差异均不显著(P＞0.05).结论认为奶牛专用微生态制剂对奶牛提高产奶量、改善牛奶品质和预防奶牛隐性乳房炎的发生有积极作用.     

我国规模牛场奶牛个体生鲜乳体细胞数水平及影响因素探析

本研究旨在探析我国规模奶牛场奶牛个体生鲜乳体细胞数（SCC）的水平、分布和影响因素。利用SAS9.0的GLM模型,统计分析覆盖16个省（市、区）,33个规模奶牛场,23 351头中国荷斯坦牛,从2007年至2009年连续3年的225 775条奶牛个体生鲜乳SCC检测记录。结果表明：奶牛个体生鲜乳SCC的总体均值为48×104cell/mL,标准差为117×104cell/mL,个体生鲜乳SCC波动范围较大;其中,77.9%的奶牛个体,其生鲜乳SCC小于50×104cell/mL,对群体混合样生鲜乳SCC的影响系数为0.26;11.3%的奶牛个体,其生鲜乳SCC介于50×104～100×104cell/mL之间,乳房处于隐性感染状态,对群体混合样生鲜乳SCC的影响系数为0.16;10.8%的奶牛个体,生鲜乳SCC大于100×104cell/mL,理论上乳房处于临床感染状态,对群体混合样生鲜乳SCC的影响系数为0.58。奶牛个体生鲜乳体细胞数评分（SCS）呈正态分布,与奶牛个体因素（产奶量、乳脂率、乳蛋白含量、胎次和泌乳阶段）和环境因素（泌乳月份、泌乳季节）差异极显著（P〈0.01）,与奶牛养殖区域、奶牛场差异不显著（P〉0.05）。我国规模奶牛场奶牛个体生鲜乳SCC主要在50×104cell/mL以下,依据影响参数能实现对生鲜乳SCC水平的调控。     

牛奶体细胞生成与乳品质量和安全的关系

牛奶体细胞数是反映奶牛乳房健康状况的重要指标之一,该指标偏高意味着奶牛可能处于亚健康或疾病状态。在奶牛正常生理状态下,牛奶体细胞的组成和数量都是基本稳定的,而当乳房外伤或疾病(如乳房炎等)发生时,牛奶体细胞数增多,产奶量降低,乳品质量下降。牛奶的品质关系到消费者的健康,因此,确保生鲜乳的质量安全是奶牛养殖工作者必须着手解决的首要问题。因此,本文围绕牛奶体细胞生成与产奶量和乳品质之间的关系展开综述,为提高乳品质量安全提供理论指导。