California Mastitis Test Results Research Articles

Comparison of California mastitis test and Draminski mastitis detector as on-farm methods for monitoring udder health in lactating buffalo

This study was conducted to compare the performance of the California Mastitis Test (CMT) and Draminski Mastitis Detector (DMD) for monitoring udder health in lactating buffalo. A total of 647 milk samples collected from 145 apparently healthy lactating buffalo cows during the first three months of the lactation period were used in this study. Both DMD and CMT were performed on-farm directly after sampling of the milk. The diagnostic accuracy of CMT and DMD was evaluated by estimating the area under the Receiver-Operating Characteristic curve (AUC) based on a value of 200,000 somatic cells per mL as a cut-point value for an infected quarter detected by direct microscopic somatic cell count. Data analysis showed that 63.76% of CMT results were “Trace” and 99% of DMD readings were greater than 300. The accuracy of CMT and DMD was close to each other; the AUC was 80.1% and 81.4% for CMT and DMD, respectively. The optimal cut-point value for CMT was Trace (T), and 515 for DMD. In conclusion, both CMT and DMD are practical on-farm tests for identifying infected udder in buffalo cows, and the suggested cut-point value for DMD is 515 for buffalo’s milk testing instead of the 300 that was assigned by the manufacturer for cow’s milk.

Association between differential somatic cell count and California Mastitis Test results in Holstein cattle

The California Mastitis Test (CMT) has been used to estimate total somatic cell count (SCC) levels in milk; however, milk with similar SCC levels occasionally shows inconsistent CMT results, which limits the use of the CMT. This observational study aimed to investigate how differential cell counts in milk influence the CMT in Holstein cattle through the novel parameters differential somatic cell count (DSCC) and macrophage proportion (MAC). We performed the CMT on d 0, 3, 5, 7, 14, and 21 after identifying mastitis, and simultaneously measured SCC, DSCC, and MAC at the quarter level. We followed 58 mastitis events occurring in 41 cows and obtained 307 quarter-level records after data cleaning. We transformed SCC to somatic cell score (SCS) and MAC to its logarithm to fit the normal distribution and analyzed the data using the cumulative logit mixed model. Results showed that both an increase in SCS (odds ratio: 3.66, 95% confidence interval: 2.89–4.64) and the logarithm of MAC (odds ratio: 4.35, 95% confidence interval: 1.91–9.91) can contribute to a higher CMT score. During the healing process of mastitis, MAC tends to increase as SCC decreases; thus, even samples with low SCC can cause positive CMT reactions. We recommend that practitioners avoid making treatment decisions based on the CMT alone. We also noted that the CMT is sensitive to subclinical mastitis with high MAC, hence it could be considered an alternative to detecting high MAC (chronic) mastitis.

Prevalence and risk factors for multidrug-resistant Escherichia coli isolated from subclinical mastitis in the western Chitwan region of Nepal

Subclinical mastitis (SCM) represents a significant burden and challenge to modern dairy management. Multidrug-resistant Escherichia coli (MDR E. coli) in milk poses a public health threat to humans especially via the consumption of unpasteurized dairy products. This study aimed to determine the occurrence of MDR E. coli in cows and buffalo in the households of the western part of the Chitwan district of Nepal. A total of 243 lactating cows and buffalo were included in this study. Milk samples (n = 972) were screened using the California Mastitis Test (CMT). The E. coli was isolated from milk samples that were positive for CMT using standard bacteriological protocols. A semi-structured questionnaire was administered to farmers to identify the risk factors associated with the occurrence of SCM in cows and buffalo. Of the 243 dairy animals screened, 42.8% (n = 104/243) showed positive CMT results. However, of the 972 quarters sampled, only 19.3% (n = 188/972) were positive for SCM. The prevalence of E. coli in these animals was found to be 16.5% in animals (n = 40/243). However, E. coli was isolated from only 5% (n = 49/972) of the quarters. Of the 49 E. coli isolated, the resistance to ceftriaxone (38.8%, n = 19/49) and ciprofloxacin (37.7%, n = 17/49) were the most prevalent. Animals with a history of mastitis were 3.57 times more likely to have SCM than other animals. Similarly, lactating animals with previous teat abrasions were 3.22 times more likely to develop SCM than animals without teat injuries. As expected, cleaning the barn once in 2 to 3 d was associated with an increased occurrence of SCM in lactating cows. This study reports the occurrence of MDR E. coli in SCM, which poses a public health threat. Creating awareness of milk pasteurization, and food safety practices are necessary among the farmers.

Changes in Somatic Cell Count, Composition and Cytokine Levels in Milk from Cows with Mastitis Due to Mixed Infections

Background: Mastitis is a mammary gland inflammation that is very common worldwide, mostly caused by bacteria, and causes enormous economic losses. Many microorganisms cause this disease. The most common causes of mastitis by these microorganisms are Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Streptococcus agalactiae (S. agalactiae). The anti-inflammatory properties of transforming growth factor (TGF)-β include: 1) limiting interferon (IFN)-γ production; 2) increasing the expression of the ınterleukine (IL)-1 receptor antagonist; 3) inhibiting macrophage production of chemokines, pro-inflammatory cytokines, nitric oxide, and reactive oxygen intermediates; and 4) increasing macrophage clearance of bacterial debris and damaged parenchymal cells. It is stated that cytokines and milk composition change in case of mastitis. In this study, it was aimed to reveal the changes in milk TGF-β1 and Tumor necrosis factor (TNF)-α concentrations and milk composition in mixed infections caused by three pathogens causing mastitis.Materials, Methods & Results: In this study, milk samples from 90 cows were divided into 5 groups. Tumor necrosis factor (TNF)-α and TGF-β1 concentrations and milk composition were determined in these milk samples. The California Mastitis Test (CMT) was applied to the cows included in the study and scoring was done. According to the CMT results of the milk samples taken, CMT(-) cows were included in group 1 (n = 22). Those with the CMT(+) were taken to the microbiology laboratory for analysis within 2 h. After the bacteria was determined, combination groupings were formed. Group 2 (n = 17) with S. aureus and E. coli, group 3 (n = 21), S. agalactiae with S. aureus, S. agalactiae and E. coli together, group 4 (n = 8) and CMT (+) but no bacterial growth formed group 5 (n = 22).Somatic cell counts were made in the milk samples taken from the cows belonging to the groupings. Somatic cell count was measured with the DeLaval Cell Counter® (Cell Counter DCC) device. Mineral matter, fat, protein, lactose, electrical conductivity and specific gravity were measured in milk samples using Lactoscan Milk Analyzer (Milkotronic/EUROPE). Milk samples were then stored at -80°C to measure TGF-β1 and TNF-α. Tumor necrosis factor-α and TGF-β1 concentrations in milk samples were measured using ELISA kits (Sunred Biological Technology).Discussion: Changes in milk TNF-α and TGF-β1 concentration and milk composition were determined in milk samples with mastitis caused by mixed infection. The TNF-α concentration of group 4 was higher than the other groups. On the other hand, the highest concentration of TGF-β1 was found in group 2. While the number of somatic cells in group 1 was lower than in groups 2, 3, and 4, there was no statistical difference between groups 1 and 5. The lowest milk fat ratio was found in group 1, and it was found to be statistically lower than groups 2, 3, and 4. While the rate of solid-non-fat of group 1 increased compared to groups 2 and 3, the highest protein ratio was found in groups 1 and 5. There was no difference between the 5 groups in terms of mineral matter ratios. While the specific gravity was highest in group 1, there was no statistical difference between the other 4 groups. Overall, it was concluded that there was an increase in TNF-α and TGF-β1 concentrations and a change in milk composition in samples with bacterial growth.Keywords: bovine mastitis, cytokine, milk composition, raw milk, transforming growth factor.

Potential role of MicroRNA as a diagnostic tool in the detection of bovine mastitis

Bovine mastitis is a major health problem that affects dairy cows and has a negative impact on milk production. The presence of microRNAs in biofluids, such as blood and milk, could play a pivotal role in the detection of bovine mastitis. The purpose of the current study was to determine the levels of microRNA gene expression in milk, in combination with other reported mastitis indicators, as a biomarker of bovine mastitis. Milk samples (n = 171) were obtained from 113 dairy cows with known disease status (i.e., healthy; n = 23 cows, subclinical mastitis; n = 45 cows, or clinical mastitis; n = 45 cows) and analyzed for the presence of MIR24-2, MIR29B-2, MIR146A, MIR148A, MIR155, MIR181A1, MIR184, and MIR223 expression using the real-time PCR (qPCR) method. The expression data were then utilized in the creation of receiver operator characteristic curves (ROC) and further analyzed by the machine learning (ML) methods. MIR29B-2, MIR146A, MIR148A, and MIR155 expression levels differed significantly among the three groups. These potential microRNA biomarkers of mastitis exhibited high sensitivity and specificity. Next, we applied ML algorithm, specifically, a decision tree (DT) model to predict the status of milk based on MIR29B-2 and MIR146A expression levels. The results suggested that MIR29B-2, when used in combination with the California mastitis test (CMT) and days in milk (DIM) data, was applicable for screening and classification of milk samples from cows as healthy, subclinical mastitis, or mastitis. MIR29B-2 appears to have sufficient discriminatory power to enable it to be utilized as a biomarker in cases where the status of a milk sample cannot be determined based on CMT results.

Review on California Mastitis Test (CMT)

The California Mastitis Test (CMT) is a quick, simple test that accurately predicts the somatic cell count of milk from individual quarters or on composite milk samples [1]. The California Mastitis Test is a simple, inexpensive, rapid screening test for mastitis. The test is based upon the amount of cellular nuclear protein present in the milk sample. Since inflammatory cells associated with mastitis are the predominant cell type present in milk the CMT reflects the SCC level quite accurately and is a rel iable indicator of the severity of infection. The test is appropriate for cow - side evaluation of udder health and the procedure can be taught quickly to producers and the milking crew. With proper training test results are very repeatable among those condu cting the test. It is necessary that producers also be made aware of the limitations of the CMT and the proper application of management decisions based on CMT results.

Relationship between pulsed wave Doppler ultrasonographic features of milk veins and CMT scores in Simmental cows

This study aimed to determine the distribution of pulsed wave Doppler ultrasonographic features of milk veins in lactating cows corresponding to udder health and the results of California Mastitis Test (CMT). Clinically healthy Simmental cows aged 3-5 years within the first 12 weeks of postpartum period were used for the study. End Diastolic Velocities (EDV), Systolic Peak Velocity (SPV), and Time-Averaged Maximum Velocity (TAMV) were the measured Doppler features of the milk veins. Numerical scales for Pulsatile Index (PI) and Resistant Index (RI) were devised in accordance with blood flow parameters. The animals were allocated to two groups according to CMT results as CMT positive (n=21) and CMT negative (n=5). No differences were found between the group regarding to PI, RI, EDV, or SPV (p>0.05). However, TAMV was found to be lower in CMT-positive animals (7.52 ± 0.85 cm/sec) compared to CMT-negative (13.90 ± 3.56 cm/sec) animals (p=0.021)

Association of California Mastitis Test Scores with Intramammary Infection Status in Lactating Dairy Cows Admitted to a Veterinary Teaching Hospital.

BackgroundSubclinical mastitis is of concern in veterinary hospitals because contagious mastitis pathogens might be unknowingly transmitted to susceptible cows and then back to their farm of origin.ObjectivesTo evaluate the California mastitis test (CMT) as an indicator of intramammary infection (IMI) in lactating dairy cows admitted to a veterinary hospital.AnimalsA total of 139 admissions of 128 lactating dairy cows admitted to the University of Illinois Veterinary Teaching Hospital over a 2‐year period.MethodsA retrospective study with a convenience sample was conducted. Medical records of cows with CMT results and milk culture results for the day of admission were reviewed. Breed, age, season, maximum CMT score for the 4 quarters, maximum CMT score difference, and clinical diagnosis were evaluated as predictors of IMI by the chi‐square test and stepwise logistic regression.ResultsAn IMI was identified in 51% of quarters. For cows admitted without evidence of clinical mastitis, the sensitivity of a CMT score ≥trace in predicting an IMI on a quarter or cow basis was 0.45 and 0.68, respectively. The distributions of maximal quarter CMT score and the maximum difference in quarter CMT score for cows without evidence of clinical mastitis did not differ (P = 0.28, P = 0.84, respectively) for cows with and without IMI. Stepwise logistic regression did not identify significant predictors of IMI in cows without clinical mastitis.ConclusionsLactating dairy cattle admitted to a veterinary hospital should be managed as if they have an IMI, even in the absence of clinical mastitis.

Prevalence of bovine subclinical mastitis and antibiotic susceptibility patterns of major mastitis pathogens isolated in Unguja island of Zanzibar, Tanzania.

A cross-sectional study was conducted between January and July 2014 in Unguja island of Zanzibar to establish prevalence of subclinical mastitis (SCM) in smallholder dairy cows and patterns of antibacterial susceptibility of major mastitis pathogens isolated. A total of 416 dairy cows from 201 farmers were randomly selected from three districts of Unguja Island to participate in the study. Questionnaire interview, field observation, individual cow examination, California Mastitis Test (CMT) and bacteriological examination were carried out. Kirby-Bauer disc diffusion technique was used to test drug sensitivity for common bacteria isolated. Based on CMT results, the overall prevalence of SCM was 28.6, 48.8 and 64.7% at quarter, cow and farm level, respectively. Prevalence of bacterial infection was recorded at 42.9, 70.9 and 78.6% at quarter, cow and farm examined, respectively. The common bacteria isolated included Staphylococcus aureus (36.8%), Pseudomonas aeruginosa (17.8%), Staphylococcus epidermidis (16.1%), Klebsiella spp. (9.5%), Micrococcus spp. (6.3%) and Escherichia coli (4.9%). In conclusion, findings of this study demonstrated high level of subclinical mastitis at farms, cows and quarters levels with both contagious and environmental bacterial pathogen involved. Therefore, efforts should be directed to the decreased subclinical mastitis by improving sanitary measures and proper milking practice.

Evaluation of an automated milk leukocyte differential test and the California Mastitis Test for detecting intramammary infection in early- and late-lactation quarters and cows.

Study objectives were to (1) describe the diagnostic test characteristics of an automated milk leukocyte differential (MLD) test and the California Mastitis Test (CMT) to identify intramammary infection (IMI) in early- (EL) and late-lactation (LL) quarters and cows when using 3 different approaches to define IMI from milk culture, and (2) describe the repeatability of MLD test results at both the quarter and cow level. Eighty-six EL and 90 LL Holstein cows were sampled from 3 Midwest herds. Quarter milk samples were collected for a cow-side CMT test, milk culture, and MLD testing. Quarter IMI status was defined by 3 methods: culture of a single milk sample, culture of duplicate samples with parallel interpretation, and culture of duplicate samples with serial interpretation. The MLD testing was completed in duplicate within 8 h of sample collection; MLD results (positive/negative) were reported at each possible threshold setting (1-18 for EL; 1-12 for LL) and CMT results (positive/negative) were reported at each possible cut-points (trace, ≥1, ≥2, or 3). We created 2 × 2 tables to compare MLD and CMT results to milk culture, at both the quarter and cow level, when using each of 3 different definitions of IMI as the referent test. Paired MLD test results were compared with evaluate repeatability. The MLD test showed excellent repeatability. The choice of definition of IMI from milk culture had minor effects on estimates of MLD and CMT test characteristics. For EL samples, when interpreting MLD and CMT results at the quarter level, and regardless of the referent test used, both tests had low sensitivity (MLD = 11.7-39.1%; CMT = 0-52.2%) but good to very good specificity (MLD = 82.1-95.2%; CMT = 68.1-100%), depending on the cut-point used. Sensitivity improved slightly if diagnosis was interpreted at the cow level (MLD = 25.6-56.4%; CMT = 0-72.2%), though specificity generally declined (MLD = 61.8-100%; CMT = 25.0-100%) depending on the cut-point used. For LL samples, when interpreted at the quarter level, both tests had variable sensitivity (MLD = 46.6-84.8%; CMT = 9.6-72.7%) and variable specificity (MLD = 59.2-79.8%; CMT = 52.5-97.3%), depending on the cut-point used. Test sensitivity improved if interpreted at the cow level (MLD = 59.6-86.4%; CMT = 19.1-86.4%), though specificity declined (MLD = 32.4-56.8%; CMT = 14.3-92.3%). Producers considering adopting either test for LL or EL screening programs will need to carefully consider the goals and priorities of the program (e.g., whether to prioritize test sensitivity or specificity) when deciding on the level of interpretation (quarter or cow) and when selecting the optimal cut-point for interpreting test results. Additional validation studies and large randomized field studies will be needed to evaluate the effect of adopting either test in selective dry cow therapy or fresh cow screening programs on udder health, antibiotic use, and economics.

Effect of mastitis on post-partum conception of cross bred dairy cows in Chittagong district of Bangladesh

Objective: The study was conducted to investigate the effect of mastitis on post-partum conception in crossed cows (Local x Friesian or Sahiwal x Friesian) in Chittagong area of Bangladesh. Materials and methods: A total of 100 lactating cows were randomly selected from thirteen small and medium size commercial dairy farms. The cows were reared under traditional feeding and management systems. Age and number of parity of the cows were 2.5 to 6 years and 1-5, respectively. On-farm California Mastitis Test (CMT) and Whit Slide Test (WST) were performed with the milk samples to diagnose mastitis. Besides, productive and reproductive data were recorded by examining the animals and interviewing the farmers. Results: The incidence of mastitis was significantly (P=0.037) higher (76% for CMT and 62% for WST) in 3.5-4.5 years old cows and lower (P=0.037) (47% for CMT) in 2.5-3.5 years old cows. The highest percentage of CMT (72%) and WST (59%) positive cases were found in cows having parity number 2. The CMT (71%) and WST (53%) test results were similar in third parity cows. The first parity cows were less prone to mastitis (47%). Mastitis had significantly (P=0.002) negative effect on days required to first heat after parturition. Mastitis was also negatively correlated with calving interval (CI) (P=0.030). More the incidence of mastitis prolongs the calving interval and the highest percentage (85% for CMT and 71% for WST) of mastitis was found in cows having 380-400 days calving interval. Lowest mastitis (54% for CMT and 48% for WST) incidence detected cows’ lowest calving interval. Significantly, more number of Service per Conception (SPC) was also required in cows having more incidence of mastitis (P=0.03). SPC was 4 for subclinical to clinical cases and 3 for clinical cases. Conclusion: Significant correlation between mastitis and post-partum conception is recorded in this study that may hamper reproductive performances. http://doi.org/10.5455/javar.2017.d203 XML PubReader

Selective, reliable blood and milk bio-markers for diagnosing clinical and subclinical bovine mastitis.

Mastitis is positioned as the most vital ailment in dairy cows in light of conventional cost examinations. The aim of the present study was to evaluate the diagnostic value of different acute phase proteins (APPs), pro-inflammatory cytokines, and oxidative stress biomarkers in healthy cows and in those with clinical or subclinical mastitis and to localize APP gene expression in the milk of mastitic cows. Therefore, 20 subclinical mastitic cows with positive California Mastitis Test (CMT) results and no clinical signs of mastitis, 15 clinically mastitic cows, and 15 healthy cows with negative CMT results and somatic cell count (SCC) of <600,000 cells/mL were selected. Milk and blood samples were collected. The present findings indicate that the biochemical parameters examined were significantly (p < 0.05) increased in cows with both types of mastitis, except for total protein, albumin, and GSH levels and the TAC, which were significantly (p < 0.05) decreased, compared with values in the controls. Surprisingly, SAA and Hp gene expression were up-regulated in milk from cows with both forms of mastitis, while Fb expression was absent. The present study demonstrates that APPs, pro-inflammatory cytokines, and indicators of oxidative stress may serve as biomarkers of clinical and subclinical mastitis. Interestingly, the expression of SAA and Hp indicates the local de novo synthesis of these APPs within the mammary glands. Furthermore, the presence of SAA and Hp transcripts in milk cells derived from pathogen-free mammary glands proved their constitutive expression. However, future studies with more extensive baseline sampling are still needed to establish and validate the reference values for APPs, cytokines, and oxidative stress markers in cows.

Prevalence of subclinical mastitis and its association with bacteria and risk factors in lactating cows of Barisal district in Bangladesh

The subclinical mastitis is more serious and is responsible for much greater loss to the dairy industry in Bangladesh. This study was per-formed to determine the prevalence of bovine subclinical mastitis and to isolate and identify the bacterial agents and risk factors associated with subclinical mastitis in randomly selected 200 lactating cows (147 local zebu and 53 crossbreds) of Barisal district in Bangladesh. California Mastitis Test (CMT) was performed on each quarter sample of lactating cows at field condition for determination of subclinical mastitis. Out of 200 lactating cows, 57 were found to be positive for subclinical mastitis by CMT. Out of 57 CMT positive cows, only 15 cows showed strong positive reactions and these samples were used for bacteriological culture to isolate and identify bacterial agents. The overall prevalence of subclinical mastitis was 28.50%. The prevalence of subclinical mastitis was significantly high in crossbreds (45.28%) compared to local zebu (22.45%) (p &lt; 0.05). Based on CMT results of quarters, prevalence of subclinical mastitis was 40.57% (n=212) in crossbreds and 20.92% (n=588) in local zebu cows. The prevalence was significantly (p &lt; 0.05) higher in cows with a daily milk yield of 3-5L and 5-7L. The highest prevalence found in mid lactation was 32.50% and the highest prevalence in the age group of 7 to 9 years was 37.50%. The prevalence of subclinical mastitis was comparatively higher (32.69%) in lactating cows where housed with earthen floor compared to concrete floor (23.17%). Among the pathogens isolated from the strongly positive subclinical mastitis samples, the most frequent bacteria were Staphylococcus spp. (73.33%). For early detection of subclinical mastitis, CMT can be performed regularly as a control measure and emphasis should be given on farm management practices, particularly on milking procedure and udder sanitation. Keywords : Bacteria, CMT, Prevalence, Risk factors, Subclinical mastitis. Normal 0 false false false EN-US JA X-NONE

Kuru döneme çıkarken enfekte ve sağlıklı meme loblarında California Mastitis Test ve somatik hücre sayısı ile bakteriyolojik muayene sonuçlarının karşılaştırılması

Bu calismada kuruya cikarma sirasinda, California Mastitis Test (CMT) sonuclarinin somatik hucre sayimi (SHS) ve bakteriyolojik muayene sonuclari ile karsilastirilmasi ve de CMT’nin kuru donem baslangicinda enfekte meme loblarinin belirlenmesinde etkinliginin ortaya konmasi amaclandi.Bu amacla 40 adet Holstein irki inege ait 157 meme lobu (3 meme lobu kor idi) verileri degerlendirildi. Saglikli meme loblarindan alinan sut orneklerine son sagim oncesi CMT yapildi ve sonuclar ayni kisi tarafindan yorumlandi. Bu uygulamadan sonra her bir meme lobundan somatik hucre sayimi ve bakteriyolojik muayene icin sut ornekleri toplandi. Somatik hucre sayimi IBC-M Bactoscan ile bakteriyolojik izolasyon ise konvansiyonel yontemle yapildi. CMT sonuclari ile SHS’lari karsilastirildiginda, CMT negatif meme loblarinda ortalama SHS 155.178, suphelilerde 221.750, +1 olanlarda 635.400, +2 reaksiyon verenlerde ise 1.782.000 hucre/ml olarak belirlendi. Bakteriyolojik acidan ureme olan meme loblarinda somatik hucre sayisi ortalamasi 195.350 iken ureme olmayanlarda ise 304.400 hucre/ml idi. Enfekte meme loblarinin %18,34’unde S. aureus, %6,4’unde Bacillus spp., %2,75’inde miks enfeksiyon ve diger meme loblarinda Streptekok spp., E. coli, Klebsiella ve Kandida izole edildi. Ureme olan ve olmayan gruplara ait ortalama somatik hucre sayilari arasindaki fark, istatistiksel acidan anlamli degildi (p>0,05).Sonuc olarak kuruya cikarilan ineklerde; subklinik meme ici enfeksiyonlarin belirlenmesinde CMT’inin tek basina yeterli olmadigi, CMT sonuclarinin bakteriyolojik muayene sonuclari ve SHS ile birlikte degerlendirilmesinin daha saglikli sonuc verecegi kanisina varildi.SummaryThe aim of this study was to compare California Mastitis Test (CMT) findings with Somatic Cell Count (SCC) and bacteriological examination at the dry-off, and to investigate the effectiveness of the CMT to detect the infected quarters at the beginning of the dry period.For this purpose, A total of 160 milk samples collected from quarters of 40 Holstein cows. 157 of these quarters were normal and 3 of them were blind. CMT was made before the last milking and the results was interpreted by the same person. After this examination milk samples were collected from each quarter for SCC and bacteriological isolation. Somatic Cell Count was made with IBC-M Bactoscan and isolation of bacteria was made conventionally. The mean SCC were 155,178 cell/ml, 221,750 cell/ml, 635,400 cell/ml, 1782,000 cell/ml, respectively, according to the CMT results. The mean SCC of the quarters that bacteriologic growth was detected were 195,350 cell/ml and the mean SCC of the quarters that bacteriologic growth was not isolated were 304,400 cells/ml. The infected quarters with S aureus (%18,34), with Bacillus spp. (%6,4), and mix infections and one for each quarter was infected with Streptococcus spp., E.coli, Klebsiella, Candida spp. Difference in SCC levels between infected and non-infected groups was not significant statistically (P > 0,05).In conclusion, only CMT was not adequate to determine subclinical intramammary infections at the dry-off cows, and to evaluate the findings of CMT with the results of bacteriological examination and SCC.

Receiver-operating characteristic curves for somatic cell scores and California mastitis test in Valle del Belice dairy sheep

Using receiver-operating characteristic (ROC) curve methodology this study was designed to assess the diagnostic effectiveness of somatic cell count (SCC) and the California mastitis test (CMT) in Valle del Belice sheep, and to propose and evaluate threshold values for those tests that would optimally discriminate between healthy and infected udders. Milk samples (n=1357) were collected from 684 sheep in four flocks. The prevalence of infection, as determined by positive bacterial culture was 0.36, 87.7% of which were minor and 12.3% major pathogens. Of the culture negative samples, 83.7% had an SCC<500,000/mL and 97.4% had <1,000,000cells/mL.When the associations between SC score (SCS) and whole sample status (culture negative vs. infected), minor pathogen status (culture negative vs. infected with minor pathogens), major pathogen status (culture negative vs. infected with major pathogens), and CMT results were evaluated, the estimated area under the ROC curve was greater for glands infected with major compared to minor pathogens (0.88 vs. 0.73), whereas the area under the curve considering all pathogens was similar to the one for minor pathogens (0.75). The estimated optimal thresholds were 3.00 (CMT), 2.81 (SCS for the whole sample), 2.81 (SCS for minor pathogens), and 3.33 (SCS for major pathogens). These correctly classified, respectively, 69.0%, 73.5%, 72.6% and 91.0% of infected udders in the samples. The CMT appeared only to discriminate udders infected with major pathogens. In this population, SCS appeared to be the best indirect test of the bacteriological status of the udder.

Relations between electrical conductivity, somatic cell count, California mastitis test and some quality parameters in the diagnosis of subclinical mastitis in dairy cows

This study was conducted to determine the effectiveness of the electrical conductivity (EC) method on the diagnosis of subclinical mastitis in dairy cows comparing with somatic cell count (SCC) and California mastitis test (CMT), and also to investigate the effect of these values on the amount of total viable bacteria, density, freezing point, and mineral substances. A total of 386 milk samples collected from quarters of 188 cows at 10 different farms were used as materials. Of the samples, 258 (66.85%) were CMT (+), 85 (22.02%) were CMT (++), and 43 (11.13%) were CMT (+++). The mean EC and SCC were 25.71, 28.02, and 29.63 mS and 249,453, 1,167,058, and 2,108,139, respectively, according to the CMT results. The total viable bacteria counts ranged from 3.4771 to 6.9395, from 3.4771 to 7.3617, and from 4.7782 to 7.5315 log CFU/mL, respectively. The average amounts of mineral substances were 0.65%, 0.70%, and 0.76%; the density values were 1.031, 1.0297, and 1.029; and the freezing points were -0.5281, -0.5285, and -0.5282, respectively. As a result, it has been concluded that EC showed similarity with the CMT and the SCC in the detection of subclinical mastitis; furthermore, its reliability would further increase when used together with the other diagnostic methods.

Análise das metodologias diretas e indiretas para a contagem de células somáticas no leite de cabras hígidas

A particularidade da secreção láctea caprina, do tipo apócrina, diferente da secreção merócrina da vaca, leva a erros de interpretação durante a realização de técnicas de avaliação da celularidade do leite de fêmeas desta espécie. Portanto, o presente trabalho teve o objetivo de determinar a contagem de células somáticas pelo método indireto California Mastitis Test (CMT), e por métodos diretos, incluindo a contagem por citometria de fluxo e a contagem microscópica direta, através da coloração de verde de metil e pironina-Y, além de comparar os métodos de contagem celular. Foram analisadas 102 amostras de 51 fêmeas caprinas, das raças Saanen, Parda Alpina e Toggenburg, criadas no Estado de São Paulo. Os animais foram categorizados segundo a fase da lactação, exame físico da glândula mamária e exame do leite. As amostras foram colhidas, após a realização do exame Califórnia Mastitis Test, em duas alíquotas, uma destinada à contagem celular automática e a outra, a contagem microscópica direta, utilizando-se o corante verde de metil e pironina- Y. De acordo com os diferentes escores do CMT, observou- se 74,5% de amostras negativas, 8,8% de amostras com escore traços, 8,8% de amostras ligeiramente positivas (+), 6,8% de amostras fracamente positivas (++) e 0,9% de amostras fortemente positivas (+++). Os valores medianos das contagens de células somáticas presentes no leite de cabras, avaliadas através de contador automático e microscopia direta, e analisadas de acordo com os diferentes escores do CMT, foram, respectivamente, 181.000, 578.000, 628.000, 1.421.500 e 5.542.000 células/mL de leite e 74.991, 271.396, 71.420, 640.995 e 5.049.394 células/ mL de leite, nos escores negativo, traços, +, ++ e +++. Os valores medianos obtidos através da contagem de células somáticas pelo método automático e microscópico direto, de acordo com as fases de lactação foram de 159.500, 508.000 e 277.500 células/mL de leite, e 62.493, 89.275 e 146.411. A correlação obtida entre a contagem celular automática e microscópica direta foi de 88%. A partir dos resultados observados pode-se concluir que existe diferença na contagem celular determinada através do método automático e microscópico sendo este último o mais adequado para a determinação da celularidade no leite de cabras.

Evaluation d’un test de dépistage précoce des mammites subcliniques des vaches

L’objectif de cette étude a été d’évaluer un test pour le diagnostic des mammites dans les élevages bovins de la région Centre de l’Algérie. L’étude a été réalisée sur 100 vaches en lactation appartenant à 15 élevages. Le test évalué a été le California Mastitis Test (CMT) dont la positivité a été indiquée par la modification de consistance du mélange lait et réactif sur une cupule à fond noir. Une analyse bactériologique a été réalisée sur tous les échantillons de lait positifs, afin de confirmer la présence d’une infection et d’identifier les pathogènes responsables. Le CMT a été positif chez 25 p. 100 des vaches. La prévalence a été deux fois plus élevée chez les vaches produisant plus de dix litres de lait. L’analyse bactériologique a montré que 96 p. 100 des échantillons de lait positifs contenaient des bactéries pathogènes, parmi lesquelles les staphylocoques ont été les plus fréquemment isolés. Ces résultats ont montré une très forte corrélation entre le CMT et la bactériologie. Ainsi, le CMT semble être un outil avantageux à développer, à petite ou à grande échelle, pour un dépistage systématique et régulier dans un programme intégré de lutte contre les mammites.

Use of California mastitis test, somatic cells count and bacteriological findings in diagnostics of subclinical mastitis

We have performed diagnostics of sub clinical mastitis in three different cow breeds with comparison of California mastitis test results, somatic cells count at quarter level and with bacteriological findings confirmation in order to justify their appliance in mastitis diagnostics. In total, 90 cows or 360 quarters of mammary gland have been examined. In 63.3 % of the examined cows, with different racial origin, positive reaction to California mastitis test have been established. Usually, positive reaction have been found in milk of one and two quarters, with reaction intensity of one and two plus. SSC higher than 200.000 in 1 ml is established in 60 % of cases and the most often causes of mastitis were staphylococcae, streptococcae and mixed infections. With continuous use of this methods it is possible to timely detect presence of sub clinical mastitis and so to obtain satisfactory results in prevention and therapy of mastitis, as well as improvement in amount and quality of milk.

Prevalence and etiology of subclinical mastitis in Awassi dairy ewes in southern Turkey

In order to study the prevalence and etiology of subclinical mastitis a bacteriological survey on 16 Awassi dairy sheep flocks in southern Turkey was conducted. A total of 1458 milk samples from 729 Awassi ewes in mid-lactation were tested with the California mastitis test (CMT). Samples from 170 (11.7%) glands and 135 (18.5%) sheep had positive CMT results. Bacteria were isolated from 93 (6.4%) udder halves and 82 (11.2%) ewes. Positive CMT and bacteriological results were combined to define subclinical mastitis. The prevalence of subclinical mastitis and positive CMT samples among the different flocks ranged from 1.9% to 11.5% and 2.8% to 21.9% of the glands, and 3.8% to 19% and 5.7% to 31.3% of the ewes, respectively, with averages of 6.4% and 11.7% of the glands, and 11.2% and 18.5% of the ewes, respectively. Coagulase-negative staphylococci (CNS) were the most prevalent bacteria, representing 76.5% of the isolates. Staphylococcus epidermidis (35.7%) was the most prevalent species, followed by Staphylococcus xylosus (10.2%), Staphylococcus saprophyticus (10.2%), Staphylococcus warneri (9.2%), and Staphylococcus intermedius (7.1%). Antimicrobial susceptibility of 78 Staphylococcus isolates was evaluated in this study. The most effective antibiotics were cephalothin (97.4%), sulfamethoxazole-trimethoprim (97.4%), amoxicillin + clavulanic acid (97.4%), enrofloxacin (94.9%), gentamycin (92.3%), and erythromycin (84.6%). The relationship between CMT +1 score and the Staphylococcus spp. isolation rate was statistically significant (P < 0.001). It was concluded that subclinical mastitis is not highly prevalent and it does not pose a significant health problem for milking Awassi sheep flocks in southern Turkey.