成膜性奶牛乳头药浴剂消毒效果及其对乳品质的影响

本研究通过对成膜性奶牛乳头药浴液进行实验室消毒试验、现场消毒试验及同类产品的对比试验,对其消毒杀菌效果及对乳品质的影响进行评价。经现场试验,该成膜性药浴液对奶牛乳头表面细菌杀菌率达99.9%,杀灭指数大于104,且对奶牛乳头无不良反应。通过对乳品质进行测定,在第15天,试验组的乳脂率、乳蛋白率与对照组相比有所提高,乳糖含量有所下降,组间差异不显著(P0.05);在第30天,试验组的乳蛋白率与对照组相比有所提高,乳糖含量、乳脂率有所下降,组间差异不显著(P0.05)。结果表明,成膜性奶牛乳头药浴液对奶牛乳头表面有很好的消毒效力,可有效杀灭奶牛乳房炎的致病菌,同时不影响牛奶的品质,可用于奶牛挤奶后乳头的药浴。     

乳头药浴涂膜剂对奶牛乳房炎致病菌体外抑菌效果评价

为探讨以聚维酮碘为主要成分的奶牛乳头药浴涂膜剂对奶牛乳房炎致病菌的体外抑菌效果,为临床试验提供科学依据,以纯水浸泡、加热制成PVA胶浆液为成膜基质,将经纯水预处理的PVP-I加入其中,随后加入一定比例甘油作为增塑剂,充分融合后制成奶牛乳头药浴涂膜剂;采用10倍稀释法进行乳头药浴涂膜剂对奶牛乳房炎临床分离的大肠埃希菌、金黄色葡萄球菌、无乳链球菌及停乳链球菌4种主要致病菌的最小抑菌杀菌浓度试验,试验同时设青霉素和头孢噻呋的抗生素对照。结果表明,乳头药浴涂膜剂4种致病菌有良好的体外抑菌和杀菌作用,其抑杀菌浓度低于头孢噻呋和青霉素。乳头药浴涂膜剂对奶牛乳房炎致病菌有较好的抑菌效果,可以用其作为奶牛乳头药浴药物替代临床常用抗生素预防。     

奶牛乳头专用消毒剂消毒效力研究

进行了奶牛乳头药浴碘甘油溶液的杀菌作用研究。试验表明,当给药浓度为0．25％（含碘）时,对大肠杆菌、金黄色葡萄球菌和溶血性链球菌的最短作用时间为15s,杀菌率均为100％,对白色念珠菌作用的最短时间为1min,杀菌率为100％。结果说明该消毒剂对上述细菌和真菌均具有良好的杀灭作用,可用于奶牛挤奶前后乳头的药浴消毒,推荐临床药浴使用浓度为0．25％f原液作1：8倍稀释）．     

国内外奶牛乳头消毒剂的研究现状

奶牛乳房炎是奶牛常见的传染病之一,给奶牛养殖业造成了严重的经济损失。临床常用抗生素来治疗乳房炎,但抗生素的过度使用会引起相关病原微生物的耐药性。利用乳头消毒剂切断病原菌的传播途径是预防和控制奶牛乳房炎行之有效的方法。文章主要综述了国内外预防奶牛乳房炎常用的单方乳头消毒剂和复方乳头消毒剂的研究情况,其中单方乳头消毒剂着重介绍了市场占有率最高的碘类消毒剂和绿色环保、低成本的二氧化氯消毒剂;复方消毒剂是奶牛乳头消毒剂的发展方向,重点介绍了氯己定等复合消毒剂与传统乳头消毒剂的应用效果的对比。此外,文章也从乳头消毒剂的工艺方面对其消毒效果进行了比较和评估,包括成膜性、皮肤喷雾型和发泡型乳头消毒剂等。最后对奶牛乳头消毒剂的发展进行了展望。     

成膜性中药乳头药浴液对奶牛隐性乳房炎的影响

奶牛乳头药浴是预防隐性乳房炎的有效措施之一。天津市畜牧兽医研究所研制的成膜性中药乳头药浴液主要成分为抗茵中药和成膜材料,用于奶牛挤奶后乳头药浴,对奶牛乳房炎常见病原菌金黄色葡萄球菌、链球菌、酵母类真菌等具有良好的抑制和杀灭作用,同时兼有薄膜的屏障作用,可阻止病原微生物从乳头侵入乳腺组织。分别采用LMT检测和乳汁体细胞数作为隐性乳房炎诊断指标,探讨成膜性中药乳头药浴液对奶牛隐性乳房炎的影响.结果表明,成膜性中乳头药浴液可减少隐性乳房炎阳性率和阳性强度,降低乳汁体细胞数,提高产奶量．、试验组比对照组隐性乳房炎发病率降低32．4％（P〈0．001）,产奶量提高6．72kg／（d·头）（35．1％,P〈0．05）。     

成膜性奶牛乳头药浴剂临床应用效果观察

本研究对成膜性奶牛乳头药浴剂的牧场应用效果进行了观察分析,将试验牛乳区分为对照组和试验组,分别使用成膜性药浴液和常规碘伏药浴液,通过测定药浴剂使用前后的体细胞数变化和隐性乳腺炎的发病率等指标来评价新型药浴剂使用效果。试验结果表明,隐性乳腺炎的乳区发病率由药浴前的41.6%下降到17.3%,与对照组比差异显著。成膜性药浴剂乳头保护效果高效持久,并能有效降低乳汁体细胞数目,预防奶牛乳腺炎症的发生,保证原料乳的质量安全。     

中药乳头浸蘸剂防治奶牛隐性乳房炎的研究

采用抑菌试验并考虑成膜的屏障作用，筛选中药制成奶牛乳头浸蘸剂防治奶牛隐性乳房炎。经63头252个乳区的临床试验证明。复方黄连(黄连 蜂胶 乳没)和复方大青叶(大青叶 五倍子 乳没)2个处方分别制成的中药乳头浸蘸剂，对奶牛隐性乳房炎均有较好的防冶效果。     

聚维酮碘成膜剂对奶牛乳头的消毒效果

本研究采用普通聚维酮碘溶液和聚维酮碘成膜剂对奶牛乳头进行消毒,分析其灭菌效果和乳房炎的转化率。试验结果表明,聚维酮碘成膜剂的杀菌效果显著高于普通聚维酮碘溶液,并且能更有效地治疗奶牛乳房炎疾病。     

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。     

副乳头对奶牛生产性能的影响及其相关基因LGR5的遗传表达分析

试验旨在探究副乳头(SNT)对奶牛产奶性能的影响及乳腺发育相关基因LGR5与副乳头发生的关系。收集325头有副乳头奶牛及同年出生的737头无副乳头奶牛的产奶性能数据,比较有、无副乳头奶牛间的产奶性能差异;利用实时荧光定量PCR技术检测有、无副乳头奶牛LGR5基因的表达差异,通过直接测序法测定有、无副乳头奶牛的LGR5基因序列,寻找该基因上的遗传突变。结果表明,无副乳头奶牛的日产奶量、高峰奶量及泌乳持续力等产奶性能均优于有副乳头奶牛,但未达到统计学显著水平;LGR5基因在有副乳头奶牛中的表达量显著高于无副乳头奶牛(P0.05);在LGR5基因第1内含子中检测到3个SNPs:rs42849472、rs42849471和rs42849470,有副乳头奶牛中3个SNPs的AA基因型频率均极显著高于无副乳头奶牛(P0.01)。结果提示,LGR5基因可能与奶牛副乳头发生有关,可作为有效的候选基因。     

奶牛纯中药乳头消毒剂的临床应用效果观察

将93头奶牛分成3组,1组31头用碘伏进行乳头药浴,2 组 32 头用鱼腥草、红花和明矾组成的中药乳头消毒剂进行药浴,30 头作为对照组,35 d的临床应用,结果如下:中药乳头消毒剂和碘伏能使临床型乳腺炎发病率降低,差异不显著(P>0 05);1组隐性乳腺炎的发病率,由药浴前的 58 1%下降到 48 4%,与对照组差异显著(P<0 05),2组隐性乳腺炎的发病率由药浴前的81 3%下降到药浴后的75%,与对照组差异显著(P>0 05);1 组和2组隐性乳腺炎的乳区发病率差异不显著(P>0 05),与对照组差异极显著(P<0 01);中药乳头消毒剂药浴后体细胞数和LDH活性明显降低,与药浴前差异显著(P<0 05);NAGase的活性药浴前后差异不显著(P>0 05),该中药乳头消毒剂对奶产量无显著影响。     

The clinical effectiveness of a post milking teat disinfection method with a foaming iodophor teat dip

The effect of postmilking teat dipping with a foaming iodophor agent on incidence of intramammary infections (IMI), incidence of clinical mastitis, somatic cell count and the characteristics of udder tissue and teat was investigated in a positively controlled field study. Two groups of animals were compared. Teats were dipped with a foaming iodophor in the treatment group (TG, 122 animals) while teats in the control group (CG, 121 animals) were dipped with a conventional iodophor teat dip with the same iodine content. A bacteriological examination of quarter milk samples divided the study period in two parts. The incidence of new IMI did not differ between the groups (1st part of trial: TG vs. CG: 6.84% vs. 9.16%, 2nd part of trial: 7.78% vs. 7.82%). There were no differences between the treatment groups regarding incidence of clinical mastitis. We detected 0.64 clinical cases per 100 days in the treatment group vs. 0.50 in the control group. The development of SCC was comparable in both groups. Teat skin and teat duct conditions showed variation during the study period. Clinical efficacy of postmilking teat disinfection with a foaming iodophor was comparable to the treatment with a conventional iodophor product.     

Efficacy of a germicidal post milking barrier-type teat dip in preventing intramammary infections

Five commercial dairy herds with 269 lactating cows participated for 12 months in a field trial to determine the effectiveness of a barrier teat dip containing chlorous acid/chlorine dioxide germicide. The right quarters of the cows in two herds and the left quarters of the cows in three herds were dipped in the experimental teat dip after the removal of the milking machine. The other quarters were dipped in a conventional 0.5 per cent iodophor product. Compared with this control product, teat dipping with the experimental dip reduced the number of new intramammary infections by 18.8 per cent, infections with major pathogens by 13.6 per cent, infections with minor pathogens by 16.8 per cent and clinical mastitis by 33.3 per cent. Statistical analysis indicated a trend towards decreased intramammary infections with coliforms and coagulase-negative staphylococci when the experimental teat dip was used. It was concluded that under the conditions of this investigation it was effective in preventing new infections due to both contagious and some environmental pathogens. However, the data suggested that it could adversely affect the condition of the skin of the teat when it was used after incorrect preparation of the udder.     

Effect of teat dipping with a germicide barrier teat dip in late gestation on intramammary infection and clinical mastitis during the first 5 days post-partum in primiparous cows

The effect of teat dipping with a barrier teat dip prior to parturition on intramammary infection (IMI) and clinical mastitis during the first 5 days post-partum was investigated in a split udder trial in 149 Holstein-Frisian heifers. Their left front and right hind quarters were dipped three times weekly (i.e. Monday, Wednesday and Friday) with a barrier teat dip containing 0.1% polyvidon iodine from day 260 of gestation until parturition. The opposite quarters (right front and left hind quarter) served as untreated control. Bacteria were isolated from 52.2% of quarter milk samples collected immediately after parturition prior to first machine milking. Staphylococcus aureus and coagulase-negative staphylococci (CNS) were predominantly found in the samples (29.2 and 35.6% of the positive samples, respectively). At parturition 6.7% of the heifers showed signs of clinical mastitis and another 27.5% developed signs of clinical mastitis during the first five days of lactation. No significant differences were found between treated and control quarters regarding IMI and incidence of clinical mastitis. Teat dipping prior to parturition in primigravid dairy heifers did not improve udder health in this trial.     

Within herd comparison of teat dipping and dry cow therapy with only selective dry cow therapy in six herds

A within herd comparison of teat dipping and dry cow therapy (full treatment) with only selective dry cow therapy (partial treatment) was carried out in six commercial dairy herds for a two year period. In four herds, the incidence of clinical mastitis was 2 to 12 per cent higher in the partial treatment group. In another herd, in which the pattern of clinical mastitis isolates was unusual in that minor pathogens were isolated from 30 per cent of mastitis cases, the incidence was 43 per cent higher in the partial treatment group. In the remaining herd the incidence was 10 percent higher in the full treatment group. Streptococcus uberis mastitis was more common in the partial treatment groups of five herds; coliform mastitis was more common in the full treatment groups of two herds and similar in both groups in the other herds. High rates of coliform mastitis were associated with poor herd environmental conditions but this was not true for Strep uberis mastitis. Rates of staphylococcus aureus and Strep dysgalactiae mastitis were low in all herds. The level of major pathogen infection in cows completing the trial in all herds increased in the partial treatment group from 5 per cent of quarters at the start to 12 per cent at the finish of the trial. In the full treatment group, however, there was only a small increase in this level. In contrast, levels of Corynebacterium bovis infection increased by 17 per cent in both treatment groups. Continued use of teat dipping and dry cow therapy was associated with a higher rate of coliform mastitis in two of the three herds where there were poor standards of hygiene and husbandry.     

THE NEW SOUTH WALES MASTITIS CONTROL PROGRAM

SUMMARY A mastitis control program based on teat dipping and dry cow therapy was evaluated in 35 herds over a 3 year period. The incidence of subclinical mastitis as detected by the Rapid Mastitis Test (RMT) fell from 34% to 12% quarters positive, a reduction of 65%. Clinical mastitis was reduced from 37 clinical cases per 100 cows in the first 3 month period to 12 clinical cases per 100 cows in the last 3 month period, a reduction of 68%. Variations in response to the program in the reduction of subclinical and clinical mastitis are discussed and the results compared with similar trials conducted overseas. The Modified Whiteside Test was used on bulk milk samples from the control herds and these results were significantly correlated with the prevalence of subclinical mastitis assessed by RMT individual quarters.     

Prevention of intramammary infections in dairy cows by the use of a premilking teat dip method with a foaming iodophor dip agent

In this study we investigated the efficacy of premilking teat dipping with a foaming iodophor teat dip in a negative controlled field study. Incidence of new intramammary infections (IMI), incidence of clinical mastitis, influence on somatic cell count (SCC) and the characteristics of udder tissue and teats were used as parameters to evaluate clinical efficacy. Predipping was compared with a negative control using a split-udder experimental design. Right teats were predipped with a foaming disinfectant containing 0.27% iodine while left teats served as controls. The latter were conventionally cleaned with damp cloth towels and dried manually with disposable paper towels ("best cleaning practice"). All teats were dipped after milking with the same dip. There were no differences between treated and control quarters with respect to incidence of new IMI during the study period (treated quarters: 6.6% vs. untreated: 6.95%), incidence of clinical mastitis (30 cases in the treatment group vs. 39 cases in the control group) and geometric mean of SCC of quarter milk samples. Spectrum of detected pathogens was also comparable. Condition of udder tissue and teat ducts did not differ between treated and control quarters.     

The use of high somatic cell count prevalence in epidemiologic investigations of mastitis control practices

A series of least-squares analytical models were developed in a cross-sectional epidemiologic study of the observed variability in within-herd high somatic cell count (SCC) prevalence, a measure of mastitis prevalence in dairy herds. The dependent variable, high SCC prevalence, was calculated as the 12-month rolling herd average percentage of lactating cows with milk SCC in excess of 283 000 cells ml⁻¹.

The first analysis involved the results of a bacteriologic survey of bulk-tank milk samples for the presence of Streptococcus agalactiae and coagulase-positive staphylococci, the two most common contagious intramammary pathogens. The presence of either pathogen in bulk-tank samples was associated with significantly higher high SCC prevalence.

The second analysis involved responses to a questionnaire concerning management and mastitis control practices. Both the practices of post-milking teat dopping and dry-cow antibiotic therapy were associated with significantly lower high SCC prevalence.

The third analysis combined the data collected for the first two analyses so that the independent variables included both bulk-tank bacteriologic results and management and mastitis control practices. This model was able to explain a greater proportion of the variability in high SCC prevalence than either of the other two models. There were three variables associated with significant decreases in high SCC prevalence namely the absence of Streptococcus agalactiae in the bulk tank milk, the adoption of post-milking teat dipping and the practice of dry-cow antibiotic therapy of all cows.

Milk somatic cell counting is now widely accepted and practiced in many countries, and individual-cow SCC data are available from large numbers of herds at a minimal expense. By corroborating the role of post-milking teat dipping and dry-cow antibiotic therapy in mastitis control programs, this study establishes the usefulness of high SCC prevalence data for epidemiologic studies of mastitis control practices.     

Effect of dry period length on the effect of an intramammary teat sealant on the risk of mastitis in cattle treated with antibiotics at drying off

AIM: The aim of this study was to evaluate, under farm conditions, the use of a teat sealant in addition to whole herd dry cow antibiotic therapy on the risk of clinical mastitis in dairy cattle at pasture, and to evaluate the impact of dry period length on that risk and the impact of the teat sealant on that risk.

METHODS: Dairy cows in three herds which used routine whole herd antibiotic therapy were randomly assigned to receive either treatment with an internal teat sealant (n=322) or no additional treatment (n=313) at drying-off between March and May 2010. All clinical mastitis cases during the dry period and to the end of the subsequent lactation were recorded by farm staff; factors affecting risk of clinical mastitis were then analysed using a Cox proportional hazards model.

RESULTS: Median duration of the dry period was 112 days with >25% of cows having a dry period >130 days. The incidence risk of mastitis during lactation for cows treated with teat sealant was 9.9 (95% CI=6.9–13.7) cases per 100 cows compared with 17.9 (95% CI=13.8–22.6) cases per 100 cows for cows treated with antibiotic alone. The addition of a teat sealant to dry cow antibiotic therapy decreased the risk of clinical mastitis only in the first 33 days after calving (Hazard risk 0.24 (95% CI=0.12–0.48)). Length of dry period did not significantly affect the risk of clinical mastitis, or the effect of adding teat sealant to dry cow antibiotic therapy on the risk of clinical mastitis.

CONCLUSIONS: In these herds where, based on the mastitis history, whole herd antibiotic therapy had been recommended, the use of a teat sealant significantly reduced the risk of clinical mastitis. This effect was limited to the first 33 days after calving; subsequently there was no significant effect of treatment. There was no effect of dry period length on risk of clinical mastitis, nor any significant interaction with treatment.

CLINICAL RELEVANCE: Combination therapy with teat sealant and antibiotic was effective under New Zealand conditions in herds using whole herd antibiotic treatment at drying off. Teat sealant reduced risk of clinical mastitis in cattle with dry periods substantially longer than 100 days, and there was no evidence that this effect changed as dry period length increased.     

Effect of application of an external teat sealant and/or oral treatment with a monensin capsule pre-calving on the prevalence and incidence of subclinical and clinical mastitis in dairy heifers

AIM: To assess the effect of applying an external teat sealant or a slow-release intraruminal monensin capsule pre-calving on the prevalence and incidence of subclinical or clinical mastitis in dairy heifers post-calving. METHODS: The studies were undertaken in 13 herds. In two herds application of an external teat sealant was compared with a negative control; in nine herds treatment with monensin was compared with controls, and in two herds treatments were applied in a 2 x 2 factorial design. Heifers were randomly assigned within herd to be treated with a slow-release intraruminal device containing 32 g monensin (n=383), or left as untreated controls (n=389), approximately 30 days before the start of the spring calving period; or to be treated with a latex external teat sealant (n=206) when calving was impending, or be left as untreated controls (n=205). Milk samples were collected from each gland between 0 and 5 days after calving and from any gland diagnosed with clinical mastitis. The effect of the treatments on the prevalence of intramammary infection (IMI), i.e. subclinical mastitis, and clinical mastitis were initially analysed at the univariate level, with associated variables (p<0.2) being used in construction of multivariable models. RESULTS: The prevalence of IMI was 18.4% at the gland level, and coagulase-negative staphylococci followed by Streptococcus uberis were the most common isolates. Treatment with an external teat sealant reduced the prevalence, compared with controls, of any IMI (12.1 (SE 1.7)% vs 16.5 (SE 2.1)%, respectively; p=0.05) or IMI caused by a major pathogen (3.8 (SE 0.8)% vs 6.0 (SE 1.1)%, respectively; p=0.05). Monensin treatment did not affect the prevalence of any IMI (p=0.68) or IMI due to a major pathogen (p=0.11). The cumulative incidence of clinical mastitis was 14.2%. Neither monensin treatment (p=0.47) nor application of an external teat sealant (p=0.71) altered the risk of clinical mastitis. There was no interaction between the monensin and external teat sealant in the two herds where the treatments were applied in a 2 x 2 factorial design. CONCLUSIONS: Application of an external teat sealant resulted in a lower prevalence of any IMI and of an IMI caused by a major pathogen. Despite monensin reducing the mobilisation of body tissue and the risk of subclinical ketosis, it had no effect on the prevalence or incidence of IMI or clinical mastitis. CLINICAL RELEVANCE: Application of an external teat sealant is an option for reducing the prevalence of IMI in pasture fed dairy heifers.