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1.
For evaluation of different factors regarding CMT results 65 goats were used. Age, milking hygiene and technique of the animals were recorded and the CMT results were evaluated in relation to those parameters. Correlations between CMT results and age as well milking hygiene and -technique respectively were found. Furtheron the CMT was evaluated as indicator for mastitis diagnosis. Therefore clinical examination of the udder, bacteriological examination of milk samples (aseptically collected) and the determination of the somatic cell count were carried out. The results showed that CMT is not specific for infected udder halves. As important udder pathogens staphylococci were found, S. aureus and CNS at the same level. This investigation has shown that CMT can be used as additional diagnostic tool concerning goat mastitis, but it should not be overestimated because of different factors which influence the cell count. For the control of udder health additional diagnostic measures are of utmost necessity.  相似文献   

2.
Five goat herds were examined to determine the prevalence and causes of subclinical mastitis and to assess the value of some laboratory tests currently used on milk samples as aids in the diagnosis of caprine mastitis. In the 170 samples taken from the pairs of mammary glands of 85 goats, the prevalence of infection in the different herds ranged from 15 per cent to 79 per cent of halves. Just over one-third (36 per cent) of all halves were infected, the organisms isolated being coagulase-negative staphylococci (80 per cent), coagulase-positive staphylococci (16 per cent), alpha-haemolytic streptococci (2 per cent) and Pasteurella haemolytica (2 per cent). Neither anaerobic organisms nor mycoplasmas were found. Tests confirmed that the coagulase-positive staphylococci were pathogens but that the coagulase-negative staphylococci rarely caused detectable disease in the caprine udder. The large between-herd variation in the geometric mean cell counts of uninfected milk samples means that somatic cell counts, the Whiteside test and the California mastitis test, are unreliable as aids in the diagnosis of caprine mastitis.  相似文献   

3.
The purpose of this study was to evaluate the usefulness of the California mastitis test (CMT) to detect an intramammary infection caused by a major mastitis pathogen in early lactation cows. The gold standard used for comparison was bacteriological culture of single milk samples. The sensitivity (82.4%) and specificity (80.6%) of a positive CMT were highest on the 4th day of lactation.  相似文献   

4.
Milk samples (n=160) from 7 clinically healthy bactrian camels were cultured to detect subclinical udder infection. The samples were assessed by the Californian mastitis test (CMT) and somatic cell count (SCC). Bacteria were recovered from 36 (22.5%) of the milk samples. Staphylococcus aureus and coagulase-negative staphylococci (CNS) were the main organisms found.Infected quarters had significantly higher mean values for the SCC (p<0.01) and CMT (p<0.001) than non-infected quarters. All 7 camels were infected with CNS but only 4 with S. aureus. CMT values for S. aureus-infected camels were significantly higher than for those only infected with CNS. The values for SCC and CMT were significantly influenced by the stage of lactation (p<0.05). No significant difference was found from the effect of the quarters. Both SCC and CMT were of value in predicting the infection status of the udder.Abbreviations CMT California mastitis test - SCC somatic cell count - CNS coagulase-negative staphylococci  相似文献   

5.
The relationship between somatic cell counts (SCC) and California mastitis test (CMT) results according to the infectious status of mammary halves and parity of Pampinta dairy ewes was evaluated. Tests were associated to bacteriological analysis and classified into three groups: uninfected (negative culture), infected by minor pathogens and infected by major pathogens. Coagulase-negative Staphylococcus (32.4%), Micrococcus spp. (32.4%), Corynebacterium spp. (5.4%), and Bacillus spp. (1.4%) were the minor pathogens isolated, while Staphylococcus aureus (27%) and Escherichia coli (1.4%) were the major pathogens isolated. A good correlation was found between the CMT and SCC, which included inflammatory and epithelial cells (r = 0.64; P < 0.0001). SCC averages for the CMT scores shown in parentheses were 223 576 (0); 245,248 (1); 397,778 (2); 1,159,109 (3) and 2,460,833 (4) cells/ml. The correlation between SCC and the infectious status of udder halves was 0.58 (P < 0.0001). The relationship between SCC and CMT profiles and infectious status studied by a discriminant analysis showed, with an accuracy of 65%, three infectious status groups. SCC arithmetic means were 244,470 cells/ml for negative culture, 1,044,100 cells/ml for minor pathogens and 2,045,652 cells/ ml for major pathogens. With the exception of 1-year-old ewes, no significant differences were observed in SCC as affected by age or parity.  相似文献   

6.
Patterns of nonclinical intramammary infection in a ewe flock   总被引：1，自引：0，他引：1  
Coagulase-negative staphylococci were the most frequent bacterial isolates from nonclinical intramammary infections (NIMI) in a ewe flock. The prevalence of NIMI was 22.9% of the udder halves at lambing and decreased to 12.5% or less between week 2 and week 6 of lactation. The decrease was due mainly to the elimination of infections involving coagulase-negative staphylococci. The frequency of new NIMI in the first 6 weeks of lactation was less than 1% of the noninfected udder halves per week. The prevalence of NIMI increased steadily from 16.1% of the udder halves at the time of weaning the lambs to 29% at postweaning week 3. The new infection rate averaged 9.7% per week during the postweaning 3 weeks. The principal bacterial isolate in the new NIMI was coagulase-negative staphylococcus. Nonclinical intramammary infection in a ewe flock was monitored by bacteriologic cultural examinations of milk samples obtained from both udder halves of 24 ewes during early lactation and of 31 ewes in the same flock during the early postweaning period. The patterns of NIMI were similar to the patterns reported in cattle.  相似文献   

7.
Screening of subclinical mastitis under field conditions is done using the California mastitis test (CMT). CMT score of ≥1 corresponding to ≥500,000 somatic cells ml−1 is commonly used as threshold of subclinical mastitis in temperate countries. However, given the innately high physiological level of somatic cells in low yielding dairy cows, this threshold may not apply to low yielding dairy cows. The current study was undertaken to investigate the clinical utility of CMT for screening of Staphylococcus aureus subclinical mastitis in low yielding smallholder dairy cows in Tanzania. A total of 1151 of quarter-milk samples were CMT tested, of these 914-originated from cows with a lactation period of 14–305 days. All samples were screened for subclinical mastitis by the CMT as well as microbiological culture of single, duplicate (two consecutive) and triplicate (three consecutive) samples as a gold standard. For the duplicate and triplicate quarter-samples, cows were considered positive for S. aureus subclinical mastitis if results of microbiologic culture for S. aureus were positive for two of two, and for at least two of the first three consecutive quarter-milk samples collected from that cow, respectively. Using a CMT score of ≥1 would classify 78.6% of the 940 quarter-samples as positive. Eighty-two percent of the samples in which S. aureus was isolated had CMT scores ≥2; this would classify 51.6% of the 940 quarter-samples as positive. For the single sample, this cut-off had sensitivity, specificity and likelihood ratio for S. aureus of 0.87, 0.83 and 4.24, respectively. For the duplicate quarter-milk samples this cut-off had sensitivity, specificity, and likelihood ratio of 0.94, 0.86, and 5.19. While, for the triplicate quarter-milk samples this cut-off had sensitivity, specificity and likelihood ratio of 0.97, 0.92 and 7.47, respectively. Based on these results and practical considerations, it is concluded that CMT score of ≥2 corresponding to ≥800,000 somatic cells Ml−1 is the best cut-off to correctly identify S. aureus intramammary infections in low yielding dairy cows in Tanzania.  相似文献   

8.
For dairy goats, both the determination of the somatic cell counts (SCC) and the interpretation of these values may be a problem. Several investigations have shown that SCC for goat's milk, even from not infected mammary halves, are often higher than for cows milk. In the three herds examined about 40% of mammary halves and 30% of the goats were infected. However large differences between the three herds could be observed. In most cases, infections were caused by coagulase negative staphylococci (CNS) or corynebacteria. The SCC of individual milk samples from goats without any udder infection hardly differed from those of goats with at least one udder half infected with CNS. In 20% and 30% of the cases the SCC was higher than 750'000 cells/ml, respectively. The relation between California Mastitis Test (CMT) reactions and udder infections was not very close. Over 20% of mammary halves infected with CNS showed negative CMT reactions. On the other hand, 25% of samples from mammary halves without a proven infection reacted positively. The large differences in individual cell counts on herd and animal level indicate that production and breeding systems might be important reasons for the higher SCC. As a consequence, the most common methods for or the control of udder health and udder infections (SCC, California Mastitis Test) are of limited value for goats. Since there was only a weak relation between milk quality properties and SCC, any arguments for the introduction of legal limits below 1 million cells per ml can hardly be found.  相似文献   

9.
The aim of the study was to determine the diagnostic value of measuring serum amyloid A (SAA) concentrations in milk of individual ewes and in farm bulk milk for monitoring udder health. Udder health was calculated by examining a randomly selected group of seven flocks at each farm visit by means of California mastitis test and bacteriological examination of 5749 milk samples. SAA was determined additionally in 267 randomly selected milk samples from six flocks. Thirty-one bulk milk samples from these farms were tested for SCC and SAA levels. Subclinical infections were detected in 29.5% of samples whereas no clinical infections were observed. Intramammary infected udder halves showed significantly elevated SAA concentrations (121.3+/-25.3 microg/ml) in milk compared to the levels of healthy udder halves (8.0+/-1.9 microg/ml; p<0.001). SAA was significantly elevated in sheep with elevated CMT scores and positive bacteriological results. Bulk milk SAA levels ranged from 18.6+/-6.7 to 37.4+/-14.1 microg/ml and showed a positive correlation with bSCC (r=0.38, p=0.018) but not with percent infected glands (r=0.022, p=0.453). This study demonstrated that SAA levels in milk can be used to detect subclinical mastitis in individual ewes whereas further investigations are needed to determine the value of measuring SAA in bulk milk for monitoring flock udder health.  相似文献   

10.
We evaluated (using latent-class models) the ability of the California Mastitis Test (CMT) to identify cows with intramammary infections on the day of dry-off. The positive and negative predictive values of this test to identify cows requiring dry-cow antibiotics (i.e. infected) was also assessed. We used 752 Holstein-Friesian cows from 11 herds for this investigation. Milk samples were collected for bacteriology, and the CMT was performed cow-side, prior to milking on the day of dry-off. At the cow-level, the sensitivity and specificity of the CMT (using the four quarter results interpreted in parallel) for identifying all pathogens were estimated at 70 and 48%, respectively. If only major pathogens were considered the sensitivity of the CMT increased to 86%. The negative predictive value of the CMT was >95% for herds with major-pathogen intramammary-infection prevalence <15%, so that selective dry-cow therapy might be reasonable for such herds if cows were screened with the CMT.  相似文献   

11.

Background

Mastitis is the most important and costly disease in dairy goat production. Subclinical mastitis is common in goats and is mainly caused by contagious bacteria. Several methods to diagnose subclinical mastitis are available. In this study indirect measurement of somatic cell count (SCC) by California Mastitis Test (CMT) and direct measurement of SCC using a portable deLaval cell counter (DCC) are evaluated. Swedish goat farmers would primarily benefit from diagnostic methods that can be used at the farm. The purpose of the study was to evaluate SCC measured by CMT and DCC as possible markers for intramammary infection (IMI) in goats without clinical symptoms of mastitis. Moreover to see how well indirect measurement of SCC (CMT) corresponded to direct measurement of SCC (DCC).

Method

Udder half milk samples were collected once from dairy goats (n = 111), in five different farms in Northern and Central Sweden. Only clinically healthy animals were included in the study. All goats were in mid to late lactation at sampling. Milk samples were analyzed for SCC by CMT and DCC at the farm, and for bacterial growth at the laboratory.

Results

Intramammary infection, defined as growth of udder pathogens, was found in 39 (18%) of the milk samples. No growth was found in 180 (81%) samples while 3 (1%) samples were contaminated. The most frequently isolated bacterial species was coagulase negative staphylococci (CNS) (72% of all isolates), followed by Staphylococcus aureus (23% of all isolates). Somatic cell count measured by DCC was strongly (p = 0.000) associated with bacterial growth. There was also a very strong association between CMT and bacterial growth. CMT 1 was associated with freedom of IMI while CMT ≥2 was associated with IMI. Indirect measurement of SCC by CMT was well correlated with SCC measured by DCC.

Conclusions

According to the results, SCC measured with CMT or DCC can predict udder infection in goats, and CMT can be used as a predictor of the SCC.  相似文献   

12.
Risk factors for intramammary infections caused by coagulase-negative staphylococci, contagious major pathogens and environmental major pathogens in early lactating heifers were evaluated at the herd, heifer and quarter levels. In total, 764 quarters of 191 dairy heifers in 20 randomly selected farms in Flanders (Belgium) were sampled. Quarter milk samples were collected between 1 and 4 days in milk and between 5 and 8 days in milk for bacteriological culture. Data were analyzed using multivariable, multilevel logistic regression analysis. Higher average herd milk somatic cell count (>200,000 cells/mL), not having an effective fly control strategy, contact with lactating cows prior to calving and moderate to severe udder edema prior to calving increased the odds of intramammary infections caused by contagious major pathogens. Poor heifer hygiene and lack of mineral/vitamin supplementation prior to calving were risk factors for intramammary infection caused by environmental major pathogens. Teat apex colonization with coagulase-negative staphylococci prior to calving seemed to protect quarters against intramammary infections caused by major pathogens. Poor heifer hygiene before calving, a non-clipped udder and not practicing of teat dipping prior to calving increased the odds of intramammary infection with coagulase-negative staphylococci. Although management is important in the prevention and control of intramammary infections in early lactating heifers, most variation in the prevalence of intramammary infections resided at the heifer and quarter levels, indicating that the susceptibility for intramammary infections around calving is mainly determined by heifer and quarter characteristics.  相似文献   

13.
Quarter milk samples (n = 543) from 152 traditionally managed lactating camels (Camelus dromedarius) in Afar Region, north-eastern Ethiopia were examined to determine the prevalence of camel mastitis and identify its bacterial causes. Out of 152 camels examined, 19 (12.5%) were diagnosed as clinical mastitis cases based on clinical signs and bacteriological examinations. Of the 257 California Mastitis Test (CMT) positive quarter milk samples 162 (63.0%) yielded pathogenic bacteria. A positive correlation was observed between CMT positive results and presence of major pathogens in camel milk samples. The main mastitis pathogens isolated were Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus agalactiae, S. dysgalactiae, and other species of streptococci, Pasteurella haemolytica and E. coli. Results of the present study suggest that mastitis in Afar camels is prevalent, Gram-positive cocci are the major isolates from camel milk samples and the CMT can be used as a screening test for the detection of mastitis in camels.  相似文献   

14.
With the aim of evaluating the effect of freezing goat milk samples on recovery of intramammary pathogens, 1200 milk samples from udder halves with subclinical intramammary infection were studied. Samples (20 ml) were frozen at -20 and at -80 degrees C. Thawing was carried out at room temperature at 7, 14, 21, 28, 58, 118, 178, 236 and 730 days after collection and bacteriological analyses were carried out to determine the number of colony forming units/ml (CFU/ml). Mixed model statistical analysis showed that bacterial group, temperature of storage, interaction of bacterial group and temperature of storage and the interaction of bacterial group, time and temperature of storage were statistically significant effects. For coagulase negative staphylococci (CNS), least squares means of log CFU/ml recovered at -20 and -80 degrees C were not different. Nevertheless, for Gram negative bacilli (GNB) a significant decrease was detected in samples frozen at -20 vs. -80 degrees C. At both temperatures and at different times of storage, significant increases were detected between log CFU/ml of CNS and values on day zero. At -20 degrees C, a significant decrease in GNB recovery was detected between freezing days zero and 730. This difference was not detected when goat milk samples infected by GNB were frozen at -80 degrees C. The results show that frozen milk samples can be useful in goat subclinical mastitis control programs.  相似文献   

15.
In a survey of about 3000 dairy cows producing low somatic cell count (SCC) milk and kept on a large-scale dairy farm, California Mastitis Test (CMT) positivity was found in 2714 udder quarters of 1491 cows. Pathogenic microorganisms were isolated from 57.6% of these 2714 udder quarters during bacteriological examination. The commonest pathogens were coagulase-negative staphylococci (CNS, 41%) and Staphylococcus aureus (32.5%); however, udder infections caused by environmental streptococci (12.8%) and coliform bacteria (6.8%) were also common. All pathogens resulted in a significant increase of the SCC in individual bulk milk (IBM) samples. In the case of CNS, this SCC elevation in IBM was significantly lower than in the case of infection by the other pathogens. In spite of this, because of the high number of udder infections caused by CNS, the adverse effect exerted by CNS on dairy herds is considered to be substantial. It was found that 54.6% of all CMT-positive cows produced IBM of an SCC below 400 thousand per ml. The milk produced by 41% of the 315 cows excreting S. aureus also had an SCC below 400 thousand per ml. This poses a serious risk of infection to the healthy herdmates. At the same time, 11% of the infected cows produced IBM with an SCC below 100 thousand per ml. On the basis of these findings, only the regular analysis of SCC of IBM can be a reliable indicator of chronic intramammary infection. As the SCC of milk produced by CMT-positive cows (and especially of those excreting pathogens) tended to increase with advancing lactation, the authors suggest that an efficient drying-off therapy should be used to restore udder health and, whenever justified, culling of cows cannot be avoided either.  相似文献   

16.
Twelve freshly lactating ewes were experimentally infected with 2 Mycoplasma (M.) bovis strains via the teat canal in the left udder. The M. bovis infection produced a febrile clinical mastitis in all infected animals. M. bovis could be re-isolated regularly from the experimentally infected udder halves and the infection spread to the other halves. Some contact animals and 4 suckling lambs became naturally infected. Antibody titres were detected by means of the indirect hemagglutination test in blood sera 2 to 3 weeks post infectionem. The pathological lesions were similar to those of the M. bovis mastitis of cows. By the end of the trial the ewes had recovered from the clinical mastitis.  相似文献   

17.
The aim of this study was to investigate the relationship between clinical findings and bacterial isolation in milk samples of meat-producing ewes. The study was conducted in 17 commercial flocks and 550 udder halves from suckling Santa Ines ewes. Initially, the clinical examination of the mammary glands and teats was performed by visual inspection and palpation of the teats and udder halves; then a scoring system was devised for all the findings. After that, the strip cup test and the California mastitis test (CMT) were performed. Then, milk samples for somatic cell counts (SCCs) and bacteriological analyses were collected. Staphylococci bacteria were the main etiological agent isolated in the present study. Upon investigation of the correlations between bacterial isolation and the clinical findings, only the presence of teat injury, pendulous udder, and alterations in the palpation of the teat were associated with bacterial isolation. A significant correlation between bacteriologically positive milk samples and CMT and SCC was also found. Thus, some clinical findings appeared as a risk factor for bacteriologically positive milk samples and can be used as a tool in mastitis control programs. However, a complete and extensive diagnosis, an appropriate therapy, and an efficient mastitis control program will require the combination of clinical examination, microbiological tests, and SCC.  相似文献   

18.
Prevalence of udder infections and mastitis in 50 California dairy herds   总被引：2，自引：0，他引：2  
The California mastitis test (CMT) and bacteriologic culture were performed on samples of bulk-tank milk and cow-composite milk (n = 23,138 cows) from 50 California dairies, 19 of the 50 with known mastitis problems. Thirty-eight (76.0%) bulk-tank milk samples and 12,334 (53.3%) cows were positive by results of the CMT. Potential mastitis agents were isolated from 5,085 (22%) cows. Staphylococcus aureus was isolated from all 50 herds, Streptococcus agalactiae was isolated from 47 herds, and Mycoplasma sp was isolated from 24 herds. For cow-composite milk samples, the prevalences were 9.3% for Str agalactiae, 9.1% for S aureus, 0.9% for Mycoplasma sp, 1.2% for coliform bacteria, 0.9% for other streptococci, 0.8% for coagulase-negative staphylococci, and 1.3% for other organisms. The relative sensitivity and the relative specificity of the CMT performed on cow-composite milk samples were 83.4% and 55.2%, respectively, and the predictive value of positive CMT results was 34.2%.  相似文献   

19.
A study was conducted on 207 lactating camels in six herds in Kenya to evaluate the California mastitis test (CMT) for the detection of intramammary infections (IMIs) caused by Streptococcus agalactiae and Staphylococcus aureus and to investigate the prevalence of both the pathogens in the camel udder. IMI with S. agalactiae was found in 12% of all camels sampled. IMI with S. aureus was present in 11% of all camels sampled. The herd-level prevalence of IMI varied between 0 and 50% for S. agalactiae and between 0 and 13% for S. aureus. Longitudinal observations over 10–12 months confirmed persistent infections for both pathogens. Observations in one herd suggested that camel pox was a contributing factor in spreading and exacerbating S. agalactiae udder infections.

The CMT had quarter-level sensitivities of 77 and 68% for S. agalactiae and S. aureus in camels, respectively. The CMT specificities were 91% for both the pathogens.  相似文献   


20.
We conducted a prospective observational study on clinical and subclinical mastitis in 30 commercial meat-producing sheep flocks from 2 regions of the province of Quebec, Canada. A total of 2792 ewes selected in late gestation were followed from lambing to weaning of lambs. The incidence of clinical mastitis for the total lactation period (average of 58 days) ranged among flocks from 0 to 6.6%, with a median of 1.2%. The most frequently isolated bacteria from the cases of clinical mastitis, in pure or mixed culture, were Mannheimia haemolytica (26%), Staphylococcus aureus (23%), and coagulase-negative staphylococci (17%). Incidence of clinical mastitis was higher in ewes that gave birth to 3 or more lambs and from the Estrie region, and was associated with an increase in ewe mortality, an increase in lamb mortality at the litter level, and a decrease in lamb's weaning weight for lambs born in multiple litter size or from ewes ≥4 years old.Among 354 selected ewes with clinically normal udder at the end of lactation, 28.8% had potentially pathogenic bacteria isolated from milk. The most prevalent bacteria were S. aureus (9.3%) and coagulase-negative staphylococci (9.3%). The risk of having a positive culture in at least one half was different between the two regions. Prevalence of ewes (n = 261) with California Mastitis Test (CMT) positive result in at least one half was 24.1 and 14.9% using a cut-off of ≥1+ and ≥2+, respectively. Prevalence of culture-positive udder halves was 11.7% for CMT-negative compared with 53.6% for CMT 3+ halves. CMT status was positively associated with the isolation of coagulase-negative staphylococci, M. haemolytica, S. aureus, and various Streptococcus species, but not with other isolated bacteria. Additionally, prevalence of CMT-positive halves was higher in ewes from the Estrie region, aged of ≥4 years versus 1 year, having clinical mastitis previously detected in the lactation and/or with low body condition score. Lamb weaning weight was associated with CMT status of ewes, while weaning weight was not associated with milk culture results. More research is needed to understand the dynamic of milk SCC and IMI in ewes from meat-producing flocks, its economical impact and best ways to control it.  相似文献   

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