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1.
The accuracy of somatic cell counts in milk samples was investigated in four studies. First, the counts recorded by one milk buyer in one supply over six months ranged from 105,000 to 401,000 cells/ml with no apparent changes in the volume of milk consigned or the level of mastitis in the herd that would explain this wide range. Secondly, the counts in daily samples from one bulk milk supply for 28 days ranged from 84,000 to 282,000 cells/ml, again with no apparent changes in the performance of the herd to explain the wide range. Thirdly, the replicated counts recorded for one sample by three separate laboratories agreed closely; however, when a sample with a high cell count was interspersed then two of the three laboratories reported high cell counts suggestive of 'carry-over' in excess of the 2 per cent 'allowable' Finally, cell count data from three separate laboratories on samples from 21 cows for 33 days revealed problems with the misidentification of samples on the farm in 1 per cent of the samples, and misidentification and mishandling of 1 to 2.6 per cent of the samples in the laboratories. All three laboratories differentiated samples from cows with subclinical and clinical mastitis, but the mean cell count of the uninfected cows varied between the laboratories with one of them recording statistically significantly higher counts over the period.  相似文献   

2.
Intramammary infections and mastitis were monitored on four occasions at three-week intervals in 61 first calf heifers in five dairy herds during the first ten weeks of lactation. Of 940 quarter milk samples examined 65% were classed as negative, 10.4% as positive for mastitis (mainly subclinical), 1.8% as group 3 (infection present but no elevation in somatic cell count) and 22.8% as group 4 (elevated somatic cell count). Seventy-seven percent of the infections detected and identified were those due to coagulase-negative staphylococci, the main species being S. hyicus, S. epidermidis, S. simulans and S. hominis. Other infections detected with Corynebacterium pyogenes (three samples), Escherichia coli (one sample), Micrococcus spp. (one sample), S. aureus (two samples) and Streptococci (non-agalactiae) (seven samples).The geometric mean somatic cell count for 23 quarters infected with coagulase-negative staphylococci was 311 x 10(3) cells / mL compared to 134 x 10(3) cells / mL in noninfected adjacent contralateral quarters. The respective figures for% cell volume in Channel 8 (mainly neutrophils) were 10.6% and 3.5%. There was a highly significant association between herd and the proportion of quarter milk samples in the four mastitis categories.  相似文献   

3.
Progress in controlling mastitis in England and Wales   总被引：1，自引：0，他引：1  
Mastitis in England and Wales has been controlled over the past 20 years while the average size of dairy herds has doubled to 65 cows. The incidence of clinical mastitis has been reduced from approximately 120 to 150 cases per 100 cows to less than 50 cases. The limited data on the prevalence of subclinical mastitis indicate that it has been reduced from over 50 per cent of cows infected to less than half this level. The application of the major mastitis control measures on the farm has doubled over the period 1973 to 1983 and had reached 66 to 90 per cent for individual measures by 1983. The national mean cell count in milk has been reduced from 573,000 to 352,000 cells/ml between 1971 and 1986, and the proportion of herds having annual mean cell counts below 300,000 cells/ml has increased from 15.7 per cent to 40.7 per cent in the last eight years.  相似文献   

4.
Weekly milk samples were taken from mammary halves from 30 goats from 8 different herds each with from 2 to 5 experimental animals throughout their lactation periods. The physiological variations in the cell counts of goats milk during lactation were investigated by a projection microscope. Only small variations were found in the average cell counts in milk samples from goats in the same herd, but big variations from one herd to another (Table I and Fig. 3.). The curves of the average cell counts in milk samples of 5 herds showed a rise at the beginning of the season at pasture (Fig. 1 and Fig. 2). Also in the housed periods the cell count showed transitory rises. The herd with the lowest average cell count (220,000/ml) was milked by an ordinary bucket milking system, while the herd with the highest average cell count (1,490,000/ml) was milked by a pipeline milking system. Five herds milked by machine had an average cell count of 720,000/ml and three herds milked by hand 540,000/ml. All the herds in the material had an average cell count of 680,000/ml.  相似文献   

5.
Routine examination of milk was performed on five herds of lactating goats in northern Italy as part of a milk quality-monitoring program in the year 2000. As part of the study, aseptic samples of foremilk were collected monthly from both half udders during the entire lactation for 305 goats, resulting in a total of 4571 samples. The samples were tested with cytological and bacteriological analyses to evaluate the relationship between mammary infections and somatic-cell count (SCC; Fossomatic (TM) method). Prevalence of intramammary infection (IMI) was 40.2% (n = 1837) of all udder-half samples examined. The most-prevalent mastitis agents were coagulase-negative Staphylococci (CNS), 80% (n = 1474 udder-half samples); within this group, Staphylococcus epidermidis was the most-prevalent species (38%). Other prevalence were Staphylococcus aureus 6% (n = 112 udder-half samples) and environmental pathogens 14% of infected udder-half samples (n = 251) with a diverse mixture of species, none of which had a frequency of >4%. Enterococcus faecalis was the most-frequently isolated among this group. Neither Salmonella spp. nor Listeria monocytogenes were detected. The risk (sample level) of infection differed across herds, parities, and stage of lactation according to results from logistic multiple regression. Infection was more common among goats in third and fourth parities and during the later stages of lactation. Of the 2734 samples from uninfected udder halves, the mean log2 SCC was 3.9 cell/ml; of the 1837 bacteriological positive samples, the mean log2 SCC was 5.6 cell/ml. According to results from a linear mixed model, concentrations of somatic cells tended to increase with increasing age and days in milk and with the presence of bacteria. Infection with S. aureus was associated with the highest SCS.  相似文献   

6.
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   

7.
Mastitis is an important disease in developing dairy industries. This paper describes a commercial mastitis control programme in Santa Cruz, Bolivia, based upon the five-point mastitis control plan and bulk tank somatic cell count (BTSCC) monitoring. Twelve farms which participated on the programme for 6 years are considered. Mean annual BTSCC fell steadily from 1200000 cells/ml to 461000 cells/ml over this time. This progressive improvement was probably a result of increasing use of and attention to detail in mastitis control practices. The control of subclinical mastitis improved in both hand-milked and machine-milked herds, though hand-milked herds consistently produced milk of higher BTSCC. The mastitis programme did not appear to influence the incidence of clinical mastitis. The paper concludes that a simple mastitis programme based on the five-point plan and BTSCC monitoring can be commercially implemented and effectively control subclinical mastitis in a tropical, developing country.  相似文献   

8.
In this paper, we analyzed a very large field data set on intramammary infections (IMI) and the associated somatic cell count (SCC) in dairy cows. The objective of the study was to analyze the impact of coagulase-negative staphylococci (CNS) IMI on cow SCC, both mean and variability, and on the potential of these infections to have a major impact on the bulk milk SCC (BMSCC). Data and milk samples for bacterial culture were collected by Quality Milk Production Services (QMPS) between 1992 and March of 2007. The QMPS program services dairy farms in New York State and other states in the Northeastern USA and operates in conjunction with Cornell University. Only records from cows where SCC and milk production data were available, and where only one organism was isolated from bacterial cultures of milk samples (or where culture was negative) were used for this analysis. A total of 352,614 records from 4200 whole herd mastitis screening sampling qualified for this study. Within herds an average of 15% (S.D. 12%) of cows sampled were infected with CNS, ranging between 0 and 100%. Average within herd prevalence of cows with a CNS IMI and an SCC over 200,000 cells/ml was 2% (S.D. 4%) with a minimum of 0% and a maximum of 50%. Results of linear mixed models showed three distinct populations of IMI statuses: negative cultures with the lowest SCC; CNS and Corynebacterium bovis with a moderate increase in SCC, and Streptococcus agalactiae, Streptococcus spp. and Staphylococcus aureus showing an important increase in SCC. Surprisingly, milk production was slightly but significantly higher in CNS infected cows compared to culture-negative cows, whereas it was strongly reduced in cows with a major pathogen IMI. The percentage contribution of CNS infections to the BMSCC was 17.9% in herds with a BMSCC less than 200,000 cells/ml. This value decreased to 11.9 and 7.9% in herds with bulk milk SCC between 200,000 and 400,000 and over 400,000 cells/ml, respectively. We concluded that very few herds with milk quality problems would have an important increase in BMSCC that could be mostly attributed to CNS infections. On the other hand, in herds with low BMSCC, CNS infections may be an important contributor to the total number of somatic cells in the bulk milk.  相似文献   

9.
This study compared the different leucocyte populations in milk from udders infected with different mastitic pathogens and in different stages of infection. Milk samples were collected from quarters free of intramammary infection, acutely infected with Escherichia coli or Staphylococcus aureus and chronically infected with S. aureus, coagulase-negative staphylococci (CNS) or Streptococcus dysgalactiae. Udder bacteriological status was confirmed after three consecutive bacteriological examinations from weekly quarter milk samples. At the time of the trial, milk samples were tested for somatic cell count (SCC) and differential cell count by both light microscopy (LM) and flow cytometry. Monoclonal antibody (mAb) CD11a/CD18 was used in order to differentiate between leucocytes and epithelial cells when tested by flow cytometry. Udder quarters free of intramammary infection had a mean SCC lower than 107 x 10(3) cells/ml in which the epithelial cells were the main cell type followed by polymorphonuclear cells (PMNs), while macrophages and lymphocytes had a lower concentration. Only 56% of the cells were labelled with the mAb anti-CD11a/CD18. In either acute E. coli- or S. aureus-infected quarters, SCC were significantly higher (P < 0.0001) than in samples from the time of inoculation, with over 90% of the cells labelled with the mAb anti-CD11a/CD18. The main cell type was neutrophils. In chronically infected cows, differences in SCC and in leucocyte patterns were found between infecting pathogens as well as between quarters harbouring the same pathogen. In all the chronically infected quarters, SCC was significantly higher (P < 0.05) than in uninfected ones. The distribution of the leucocyte patterns in the quarters infected with S. dysgalactiae did not differ from that in quarters with acute infection with both E. coli and S. aureus. In the cows chronically infected with S. aureus or CNS, the proportion of PMN was higher but not significantly different from quarters free of intramammary infection, while epithelial cells were significantly lower (P < 0.05). The T lymphocytes bearing CD4+ or CD8+ were significantly higher in quarters chronically infected with S. aureus than in quarters free of intramammary infection and in quarters acutely infected with either E. coli or S. aureus. In all samples B cells were negligible.  相似文献   

10.
The somatic cell counts of ewes' milk were determined by an electronic particle counter (Coulter Counter). Of 1408 apparently normal milk samples, 98.2% had a somatic cell count lower than 1.0 x 10(6) cells/ml and 85.8% of 254 bacteriologically positive samples had a count higher than 1.0 x 10(6) cells/ml. Values exceeding 1.0 x 10(6) cells/ml are indicative of subclinical mastitis, if samples were collected from clinically healthy mammary glands.  相似文献   

11.
Beaudeau F  Fourichon C  Robert A  Joly A  Seegers H 《Preventive veterinary medicine》2005,72(1-2):163-7; discussion 215-9
Variations in test-day bulk milk somatic cell count (BMSCC) according to bovine viral diarrhoea virus (BVDV) infection status of the herd were quantified. Infection statuses were defined, based on bulk-milk antibodies measured twice 4 months apart. On each test-day, BMSCC was calculated as the weighted mean of the individual cow-level somatic cell counts. A total of 97,985 test-days in 7252 herds were considered. The effect of the BVDV-infection on BMSCC was assessed using mixed linear models, controlling for herd (random), proportion of primiparous cows and average days in milk on test-day. Considering test-days contemporary to the BVDV-status definition-period, the increase in BMSCC was 12,000 (P<0.001), 27,000 (P<0.001) and 6000 (P=0.97) cells/ml in past-infected recently recovered, past-but-still-infected and recently infected herds respectively, compared with not recently infected herds. A carry-over effect (at least 1 year) of BVDV-infection on BMSCC was also evidenced in past-infected recently recovered, past-but-still-infected and recently infected herds.  相似文献   

12.
Twelve dairy herds that had participated in the Pennsylvania Dairy Herd Improvement Association (DHIA) program for at least 12 months, that had a 12-month mean DHIA somatic cell count greater than 700,000 cells/ml, and that had greater than 25% of lactating cows infected with Streptococcus agalactiae participated in a herd blitz treatment program. Initially, quarter milk samples for bacteriologic culturing were collected from all lactating cows. Subsequently, all cows identified as infected with Str agalactiae were treated, using a commercial penicillin-novobiocin intramammary infusion product. In addition, a herd mastitis management program of postmilking teat dipping and treatment of all cows at the start of the nonlactating period was instituted. Thirty days after the initial herd visit, samples from all lactating cows were again cultured, and cows infected at that time were treated. Twelve months after the initial herd visit, samples from all lactating cows were again cultured. Mean prevalence of infection with Str agalactiae decreased (P less than 0.05) from 23.0% of quarters and 41.6% of cows initially to 3.4% of quarters and 9.3% of cows at 30 days and 1.6% of quarters and 4.2% of cows at 1 year. Mean herd DHIA somatic cell count decreased (P less than 0.05) from 918,000 cells/ml initially to 439,000 cells/ml at 30 days and 268,000 cells/ml at 1 year.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
This study was conducted to investigate the normal somatic cell count (SCC) and to define subclinical mastitis in Murrah buffaloes. Data were collected from 60 clinically normal buffaloes stationed at five farms of Chitwan Nepal and Buffalo Research Center, Hissar, India. Somatic cell count was measured using the Newman-Lampert staining technique. The upper limit of SCC was determined >or=200 000/ml of milk based on the mean +/- 2SD of a total SCC. Abnormal data of the SCC was repeatedly removed, which lie beyond the values of more than mean + 2SD until all the data come to lie within (mean + 2SD). Averages of SCC of right front and right hind quarters were significantly higher than left front and left hind quarters. Nearly 94% of California mastitis test (CMT) negative quarters were having somatic cells >or=200 000/ml. The mean SCC of CMT positive quarter was significantly higher (P < 0.01) than CMT negative quarters. Subclinical mastitis was diagnosed on the basis of samples with SCCs >or=200 000/ml with positive bacterial cultures. Subclinical mastitis was found in 21.7% buffaloes and 8% of the quarter foremilk samples. Neutrophil counts were significantly higher in subclinical mastitis milk.  相似文献   

14.
Eighteen dairy herds were studied, 12 with a 12-month Dairy Herd Improvement Association herd mean somatic cell count (SCC) less than or equal to 150,000 cells/ml (low SCC) and 6 with a 12-month mean SCC greater than 700,000 cells/ml (high SCC). At the outset of the study, quarter samples for bacteriologic culture were collected (in duplicate) from all quarters of all lactating cows (whole herd culture). Subsequently, quarter milk samples for culture from all cows with clinical mastitis were collected for a period of 6 months. In the herds with low SCC, results of whole herd culture revealed low prevalence of intramammary infection attributable to all major pathogens (less than 4% of all quarters). Prevalence of infection with Streptococcus agalactiae (22.2% of all quarters) and Staphylococcus aureus (6.6% of all quarters) was significantly (P less than 0.05) higher in the herds with high SCC. Mean incidence of clinical mastitis in the herds with low SCC was 4.23 infections/100 cows/month (range, 0.42 to 10.25 infections). In the herds with high SCC, mean incidence was 2.91 infections/100 cows/month (range, 1.33 to 3.92 infections). In the herds with low SCC, infection type, as mean percentage of total clinically infected quarters sampled for culture/herd, was 0.0%, 2.2%, 12.3%, 43.5%, and 28.6% for Str agalactiae, S aureus, streptococci other than Str agalactiae, coliforms, and organisms not isolated, respectively. Respective percentages for the herds with high SCC were 41.5%, 18.3%, 12.6%, 8.0%, and 8.8%. During the study period (from April through January), incidence of clinical mastitis and clinical mastitis caused by coliform bacteria were highest in July and August for herds with low SCC.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
Thirty-two dairy herds, 16 with low somatic cell counts (LSCC; Dairy Herd Improvement Association 12-month mean herd SCC less than or equal to 150,000 cells/ml) and 16 with high somatic cell counts (HSCC; Dairy Herd Improvement Association 12-month mean herd SCC greater than or equal to 700,000 cells/ml) were evaluated to determine the relationship between the prevalence of mastitis in each herd and each herd's mastitis control and management practices. Once for each herd, duplicate quarter milk samples were collected from the lactating cows, a survey of herd mastitis control, milking hygiene, and management practices of each herd was performed, and milking-machine function was evaluated. Of the 16 herds with LSCC, 2 (12.5%) had Streptococcus agalactiae isolated and 7 (44%) had Staphylococcus aureus isolated. Both organisms were found in all of the herds with HSCC. In herds with LSCC, the mean percentage of quarters infected with Str agalactiae was 0.1%, the mean percentage infected with streptococci other than Str agalactiae was 1.9%, and the mean infected with S aureus was 0.7%. In herds with HSCC, 25.7% of the quarters were infected with Str agalactiae, 3.7% were infected with streptococci other than Str agalactiae, and 7.6% were infected with S aureus. A program of postmilking teat dipping and treatment of all cows at the beginning of the nonlactating period was practiced more frequently in the herds with LSCC (81.3%) than in the herds with HSCC (37.5%). Major differences were not found between the 2 groups of herds in the use of the more common milking hygiene techniques or in the maintenance and functional characteristics of the milking equipment.  相似文献   

16.
A two-and-a-half-year study was undertaken in 32 commercial dairy herds within a 50-mile radius of Guelph, Ontario, in order to provide a comprehensive evaluation of relationships amongst diseases, production parameters and risk of removal in Holstein-Friesian cows. Diseases consisted of common clinical diseases as well as two subclinical diseases (mastitis and ketosis).

The data set consisted of a total of 2875 lactation records from 2008 cows. The means and standard deviations of some of the production parameters were: age 4.9 ± 2.5 year, breed class average for milk 140 ± 26 BCM units, milk production per day of life 18.0 ± 3.8 kg and days to conception 118 ± 60 days. Lactational incidence rates of the more common diseases were: reproductive tract infections 0.182, mastitis 0.168, cystic ovaries 0.104, subclinical ketosis 0.096, retained placenta 0.086 and ketosis 0.074. The average lactation mean log somatic cell count was 179 000 cells/ml. The times postpartum to the first diagnosis of all disease conditions are presented.  相似文献   


17.
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   

18.
The association between quarter somatic-cell counts (QSCCs) of milk and the risk of clinical mastitis (CM) was investigated in a 1-year study on three dairy herds in Somerset, UK. The three herds had 95-130 milking cows and an annual mean bulk milk somatic-cell count (BMSCC) of <150 x 10(3)cells/ml. The farms were visited every 4-6 weeks at morning milking when quarter-milk samples were collected. The farmers recorded all cases of CM and were trained to collect sterile milk samples from affected quarters, before treatment for bacteriology.The three herds had CM incidence rates of 25.4, 55.2, and 67.6 quarter-cases per 100 cow-years. Escherichia coli and Streptococcus uberis were cultured from approximately 50% of cases. QSCC was categorised and the risk of CM occurring in the month after the QSCC was examined using multilevel models to account for the correlated nature of the dependent data. Three models were developed: one for all cases of CM, one for those caused by coliforms and one for those caused by S. uberis. When all cases of CM were considered, quarters with somatic-cell count (SCC) 21-100 x 10(3)cells/ml had reduced odds (OR=0.60, P=0.06) and quarters with SCC >200 x 10(3)cells/ml has over three time the odds (OR=3.7, P<0.01) of CM compared with QSCC 1-20 x 10(3)cells/ml. When only coliform CM were investigated, quarters with SCC 6-200 x 10(3)cells/ml had reduced odds of coliform CM (OR=0.47, P=0.04) compared with QSCC 1-5 x 10(3)cells/ml, and SCC >200 x 10(3)cells/ml were not significantly different from the baseline. Finally, when S. uberis CM were investigated, quarters with SCC >200 x 10(3)cells/ml had more than three times the odds of S. uberis CM compared with QSCC 1-20 x 10(3)cells/ml (OR=3.73, P<0.01). QSCC <21 x 10(3) and >200 x 10(3)cells/ml are associated with increased odds of CM in the following 4-6 weeks; this association may be pathogen specific.  相似文献   

19.
The concentrations of lactoferrin (Lf) in quarter milk from normal lactating cows and subclinical mastitic cows were measured to determine whether the Lf concentration in milk is influenced by the age of the cow, the stage of lactation, number of milk somatic cells and the presence of pathogens. Lf concentrations in 111 quarter milk samples from 28 normal lactating cows and 270 quarter milk samples from 198 subclinical mastitic cows were measured by means of a single radial immunodiffusion test. Lf concentrations (means +/- standard deviations; logarithmic form) in normal cows and subclinical mastitic cows were 2.23 +/- 0.39 and 2.70 +/- 0.39, respectively. The mean milk Lf concentration (log) in subclinical mastitic cows was significantly (p<0.01) higher than that in normal cows. The mean milk Lf concentration (log) in normal lactating cows aged 5 years was lower than those in normal lactating cows aged 2 years (p<0.01) and 3 years (p<0.05). The results showed that the milk Lf concentration (log) is associated with age of the dairy cow (one-way analysis of variance test, p<0.01). The mean milk Lf concentration (log) in the latter lactational period tended to be higher than those in the peak and middle periods. Milk Lf concentrations (log) tended to be proportional to the level of the somatic cell count (SCC) score. Mean milk Lf concentrations (log) in subclinical mastitic cows infected with Staphylococcus aureus and with other streptococci species were significantly (p<0.01) higher than those in cows infected with coagulase-negative staphylococci and with Corynebacterium bovis.  相似文献   

20.
Somatic cell counts were performed monthly on bulk tank milk samples for all producers in the Ontario counties of Hastings, Lennox/Addington and Prince Edward throughout 1978 and 1979. Other data were obtained via a structured questionnaire and from the records of the Ontario Milk Marketing Board. Many producers have not adopted practices that have been advocated for the integrated control of mastitis. For example, 43.3% of producers surveyed used single service paper towels, 63.3% regularly used teat dip and 56.5% dry cow therapy. The mean of the average monthly somatic cell count for all producers for 1978 was 621.1 x 10(3) cells/mL. This latter value was used to divide the producers into case (higher than average) and control (lower than average) groups. Control herds averaged 95.9 liters more shipped milk per cow per month than case herds. Milk from control herds averaged 0.22 percentage points higher than case herds for each of average fat and lactose, and 0.16 percentage points higher for protein. The linear regression of monthly shipped milk on the respective monthly bulk tank somatic cell count indicated a loss of 13.26 L/cow/month for each 100,000 increase in somatic cell count.  相似文献   

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