头孢氨苄治疗奶牛乳房炎的效果及在牛奶中残留规律的研究

研究通过临床确诊患乳房炎的奶牛71头,采用头孢氨苄的4种不同用药方法进行治疗,用药后观察治疗效果及检测其残留规律。结果显示:肌注头孢氨苄、肌注头孢氨苄联合肌注普鲁卡因、静注头孢氨苄、静注头孢氨苄联合乳管注入普鲁卡因4种用药方案治疗奶牛乳房炎的有效率为75%～88.9%,平均有效率为81.8%;治愈率在65%～83.3%之间,平均治愈率为74.6%。通过检测,单独用药和联合用药对残留规律的影响不大,二者差异不显著。单独肌肉注射和联合肌肉注射普鲁卡因的弃奶期分别为59、58h(2.5d);单独静脉注射、联合乳管注入普鲁卡因的弃奶期分别为56、52h,4种用药方法的弃奶期比标准规定的2d延长了12h。     

检测奶牛乳汁孕酮的免疫生物传感器优化

为了完善已建立的孕酮免疫生物传感器的检测性能,本试验应用碳化二亚胺法将11α-羟基孕酮半琥珀酸和OVA制备成孕酮完全抗原,其浓度达0.6 mg/m L。在此基础上建立了以乳汁为基质的孕酮生物传感器的标准曲线(y=-4.9461x+8.7982,R2=0.993 2),进一步确立了检测乳汁孕酮的线性范围为0.31 ng/m L~50ng/m L,检测限为0.31 ng/m L,灵敏度为0.15 ng/m L,而且孕酮与皮质酮、皮质醇、雄烯二酮的免疫交叉反应较低,表明特异性较好。批内、批间变异系数分别为7.7%和7.5%,回收率为95.8%~115.7%,生物传感器稳定性在4℃保存4 d。该优化的奶牛乳汁孕酮免疫生物传感器的性能参数符合规定的标准,为检测妊娠、乏情和繁殖障碍疾病的奶牛乳汁孕酮含量提供了工具。     

奶牛乳房炎的治疗方法

奶牛乳房炎是乳腺受到物理、化学、微生物刺激所发生的一种炎性变化.本病以乳汁的理化性改变为主,由多种非特定的病原微生物引起,不仅影响产奶量、牛乳质量、延长产后发情和妊娠时间,严重时还能使奶牛泌乳机能丧失而被淘汰,是世界奶牛业的主要危害因素之一[1-3].笔者根据多年的治疗经验,总结如下.     

应用体细胞计数监测奶牛隐性乳房炎

奶牛乳汁中体细胞数的变化受多方面因素的影响。本文主要论述用体细胞计数检测奶牛隐性乳房炎技术、以及将体细胞数作为标记性状、选育具有乳房炎抗性奶牛的研究。     

复合蛋白酶乳房注入剂对泌乳期奶牛乳房炎(临床型)的疗效试验

本试验通过对患牛体细胞以及其它临床指标的检测和观察,评估了复合蛋白酶注入剂对临床型奶牛乳房炎的治疗效果。按照1支/乳区·次,连续用药3次,每次间隔12 h给药的临床使用方案,推荐剂量组(糜蛋白酶8 mg+胰蛋白酶8 mg组)制剂对临床型奶牛乳房炎的有效率达到88.2%,治愈率高达70.6%;对患病乳区病原菌菌株数清除作用减少50%以上;奶牛乳房炎评分均值从5.70提升到7.90;体细胞均值从138.20万个/m L降低到75.40万个/m L。与传统抗生素药物的治疗比较,虽然治疗效果不及有些种类的抗生素的效果,但作为一种全新概念的复合蛋白酶制剂用做奶牛乳房炎的治疗药物,不仅避免了细菌耐药性和药物残留等问题,而且为复合酶制剂的开发和应用于治疗奶牛乳房炎提供了全新的思路。     

康贝防治奶牛隐性乳房炎疗效观察及对乳汁体细胞数的影响

奶牛乳房炎的研究至今已有100多年的历史,虽然取得一些令人可喜的成果,但奶牛乳房炎仍是当今奶牛场的常发病和难以防治的疾病之一.特别是奶牛隐性乳房炎,由于无明显的临床症状,隐蔽性强,发病率高,主要影响奶牛泌乳量和乳汁的质量,造成严重损失,是影响世界乳业发展的重要因素之一.奶牛隐性乳房炎在我国发病率较高,据笔者调查表明,河北省部分地区奶牛隐性乳房炎发病率高,乳区阳性率为40.1%,头阳性率为68.45%,这与其他学者报道相符[1、2、3].自1945年抗生素应用到兽医临床上以来,奶牛乳房炎的防治有了重大突破.但是由于抗生素的滥用,致使病原抗药性增强,且高药物残留等问题一直是困扰兽医工作人员的难题.因此寻求一种高效、绿色、简便易行的防制奶牛隐性乳房炎的方法一直是兽医科技人员的研究热点.康贝是一种生物活性制剂,不含有任何激素及抗生素.本试验的目的在于试验研究康贝对奶牛隐性乳房炎的防治作用,试验包括康贝防治奶牛隐性乳房炎疗效观察、康贝对奶牛血液流变学指标的影响及康贝清除氧自由基试验等内容,现将康贝防治奶牛隐性乳房炎疗效及对乳汁体细胞的影响做一初报,其他内容另文发表.     

Acute phase proteins in serum and milk from dairy cows with clinical mastitis

The serum concentrations of haptoglobin, serum amyloid A and alpha1 acid glycoprotein were determined in serum collected from healthy dairy cows and cows with clinical mastitis, graded as mild (clots in milk) or moderate (clots in milk and visible signs of inflammation in the mammary gland/s) to assess their relative diagnostic value in detecting the disease. The concentrations of haptoglobin and serum amyloid A were also measured in milk collected from infected and uninfected quarters. The concentrations of haptoglobin and serum amyloid A were higher in the serum and milk from the cows with mild or moderate mastitis. The diagnostic value of haptoglobin in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 82 per cent and 94 per cent respectively with serum and 86 per cent and 100 per cent with milk. The diagnostic value of serum amyloid A in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 83 per cent and 90 per cent with serum and 93 per cent and 100 per cent with milk. The diagnostic value of serum alpha1 acid glycoprotein in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 62 per cent and 91 per cent.     

The effect of veterinary-treated clinical mastitis and pregnancy status on culling in Swedish dairy cows

The interaction of the effects of pregnancy status and veterinary-treated clinical mastitis on culling in Swedish dairy cattle was analyzed with survival analysis. The data were from 978,780 cows with first calvings between 1988 and 1996. Four breeds (Swedish Red and White (SRB), Swedish Friesian (SLB), Swedish Polled Breed and Jersey) were included in the analysis, together with the SRB x SLB crossbreds. Length of productive life was defined as the number of days between first calving and culling or censoring (end of data collection). The model (Weibull proportional hazard) included the interaction of parity by pregnancy status by veterinary-treated clinical mastitis, peak test-day milk-yield deviation within herd-year-parity, age at first calving, year by season, region, breed, herd production level, and the random effect of herd. The effects of pregnancy status and veterinary-treated clinical mastitis were modeled as time-dependent covariates. The lactation was divided into five stages during which a veterinary-treated clinical mastitis and culling might occur and in which the pregnancy status was assumed to be known and culling could occur. Open cows had a pronounced effect on culling: they had a very high risk of being culled in all lactations, and it was even higher if they were treated for mastitis in early lactation. For pregnant cows, the later they got pregnant during the lactation, the greater their risk to be culled. The risk associated with cases of veterinary-treated clinical mastitis remained important throughout the lactation.     

Detection of delayed cyclicity in dairy cows based on progesterone content in monthly milk samples

We examined whether infrequent milk sampling for progesterone analysis could be used as a management or diagnostic tool by the dairy farmer to predict delayed ovarian cyclicity in dairy cows. The data included 1040 lactations from 324 Swedish Red cows and 183 Swedish Holstein cows and were randomly divided into two datasets. A logistic regression model was fit to the first dataset and the model was then validated on the other dataset. The model was also validated using a British dataset comprising 1212 lactations from 1080 British Holstein-Friesian cows. The dependent variable was whether delayed ovarian cyclicity occurred or not, delayed ovarian cyclicity defined as progesterone levels below threshold value for the first 56 or 45 days postpartum in the Swedish or British dataset, respectively. The basic model included the effects of breed, parity, season and housing type. To the basic model various progesterone-based measurements were added. These were the interval from calving to commencement of luteal activity and the percentage of samples with luteal activity within 60 days after calving, using all samples in the databases or one sample per month. The accuracy of the conditional probability of delayed ovarian cyclicity calculated with the different models was obtained using receiver operating characteristic (ROC) curves and calculating the area under curve. Sensitivity and specificity were calculated for cut-off probabilities using the ROC analyses. The accuracy was highest (0.94-0.99) when including the progesterone measurements based on milk sampling for progesterone analysis 2-3 times per week. The accuracy was between 0.85 and 0.88 when the progesterone measurements with monthly milk sampling were added to the model and 0.76 or 0.67 with the basic model. This study clearly shows that infrequent milk sampling for progesterone analysis, such as once a month as in the regular milk recording system, could be used to predict delayed ovarian cyclicity in dairy cows. This increases the opportunity for earlier treatment of anovulatory dairy cows and may therefore decrease involuntarily extended calving intervals in the herd.     

Progesterone concentration in defatted milk of dairy cows in early pregnancy.

Progesterone concentrations have been measured in defatted milk of British Friesian cows of four herds during the oestrus cycles (other than short cycles) immediately before artificial insemination (AI) at oestrus and immediately after AI (in non-pregnant cows), and during early pregnancy. Differences in mean progesterone concentrations between herds were significant (P less than 0.05) on all days within the day 10-18 period after AI, both in pregnant and in non-pregnant, inseminated cows but were not significant between pregnant and non-pregnant cows within herds until day 17 or 18. It is concluded that up to this time (that of luteolysis in non-pregnant cows) undefined factors, variable among herds, can have a much greater influence on the rate of progesterone secretion by corpora lutea and consequent progesterone concentration in plasma and milk than does the presence of conceptuses. Maximum mean progesterone concentration reached during early pregnancy in two herds did not differ significantly; it was reached in the 11-15-day period in one herd but not until 46-50 days in the second. Mean progesterone concentration declined after day 90.     

Experimental Corynebacterium pseudotuberculosis mastitis in dairy cows

The inoculation of 2000 colony-forming units of Corynebacterium pseudotuberculosis into one teat canal of each of three cows resulted in severe, chronic, pyogranulomatous mastitis. Within three days the cows had a reduced haematocrit, haemoglobin concentration and red cell count. The anaemia was initially normocytic, normochromic and non-regenerative, and was associated with a brief peak of neutrophilia; a regenerative response became evident two to three weeks later. Clinical signs of mastitis appeared seven to 14 days after the inoculation, with a peak of high fever, more severe anaemia, a second peak of neutrophilia and the complete cessation of milk production from all quarters; extensive and severe pyogranulomatous mastitis developed in the inoculated quarters. No other lesions were detected postmortem, and C pseudotuberculosis was cultured from the affected quarters but not from the supramammary lymph nodes and viscera.     

Haptoglobin and serum amyloid A in milk from dairy cows with chronic sub-clinical mastitis

New tools are needed to detect chronic sub-clinical mastitis, especially in automatic milking systems. Haptoglobin and serum amyloid A (SAA) are the two most sensitive bovine acute phase proteins, and their concentrations increase in milk from cows with clinical mastitis and in milk from cows with experimentally induced chronic sub-clinical Staphylococcus aureus mastitis. The aim of this study was to further evaluate the potential for haptoglobin and SAA in milk as indicators of chronic sub-clinical mastitis. Quarter milk samples were collected from 41 cows with a mean composite milk somatic cell count (CSCC) above 300,000 cells/mL during at least two months prior to sampling. Quarter milk samples were also taken from eleven cows with a mean CSCC below 80,000 cells/mL during at least two previous months. These samples were analysed for haptoglobin, SAA, adenosine triphosphate (ATP) activity and bacterial growth. The samples were grouped according to their ATP, haptoglobin and SAA status. ATP+ samples had ATP > 2 x 10(-10) mol/mL, Hp+ and SAA+ samples had detectable levels of haptoglobin (> or = 0.3 mg/L) and SAA (> or = 0.9 mg/L), respectively. In udder quarter samples from healthy cows, 42 out of 44 samples belonged to the ATP-Hp-SAA- group. Among cows with chronic sub-clinical mastitis, the ATP+Hp+SAA+ group contained 66 out of 164 samples while 44 samples belonged to the ATP+Hp-SAA- group. Detectable levels of haptoglobin and SAA were found in 92 and 80 samples, respectively. Growth of udder pathogens was detected in 28 samples and Staphylococcus aureus was the most common bacteria. In conclusion, haptoglobin and SAA concentrations below the detection limit were considered as good indicators of healthy udder quarters. A substantial variation in haptoglobin and SAA concentrations in milk was observed in udder quarters with chronic sub-clinical mastitis.     

影响奶牛乳蛋白质含量的因素及营养调控技术研究

乳蛋白是牛奶中最重要的成分之一,受多种因素的影响,如品种、奶牛泌乳阶段、胎次、疾病和饲料组成与营养等。文中阐述了乳蛋白的合成机理及有关影响乳蛋白的营养和非营养因素;同时对国内外乳蛋白营养调控的技术进展作了全面的阐述,旨在为提高乳蛋白含量和产量提供参考。     

The milk progesterone test as an aid to the diagnosis of cystic ovaries in dairy cows

Two field trials were carried out by five experienced veterinary surgeons to evaluate the milk progesterone test as an aid to the differential diagnosis of cystic ovaries in dairy cows. Of 200 cystic cows, 71 per cent were diagnosed clinically as follicular and 29 per cent as luteal cases; 80 per cent of the cases occurred in the six winter months November to April. The progesterone assay indicated that the diagnosis was correct in 84 per cent of the follicular cases but only 54 per cent of the luteal cases. Seventy-four per cent of the confirmed cystic cases responded to treatment within two weeks according to milk progesterone tests and there were no significant treatment differences. Overall, 80 per cent of the cows became pregnant on average 38 days after treatment having received an average of 1.70 inseminations each. Milk yield data in the first trial indicated that the cystic cows were not significantly higher yielders than their herd-mates.     

Relationship between milk urea concentration and the fertility of dairy cows

The relationship between milk urea concentration and the fertility of dairy cows was examined in two studies. The first examined the relationship between bulk milk urea concentration and overall herd fertility, using data collected from 250 herds in the UK. There was no relationship either between bulk milk urea concentration and fertility, or between changes in bulk milk urea concentration and fertility. The second study compared the relationship between the milk urea concentration five days after service, and the fertility of individual cows on 11 UK dairy farms. There was no significant difference between the milk urea concentration of the cows that became pregnant and those that did not.     

黄芪中药组合方剂对奶牛乳房炎的治疗效果

奶牛在产奶阶段发生较多的疾病主要为乳房炎,从而影响产奶量,奶牛一旦患上乳房炎,会导致奶牛生长发育缓慢,经济效益也会受到很大的影响.笔者在多年的临床上,应用黄芪对奶牛乳房炎进行防治,取得了显著治疗效果.本文重点对黄芪中药制剂在奶牛乳房炎防治中的生理功能和预防奶牛乳房炎的作用机理进行阐述,以供同行参考.