Somatic Cell Reference Samples for Calibration of Milk Somatic Cell Counting Methods

1984 ◽  
Vol 47 (9) ◽  
pp. 694-696 ◽  
Author(s):  
T. J. LINTNER ◽  
C. W. HEALD ◽  
R. J. EBERHART

Somatic cell count samples (SCCS) for use in calibration of milk somatic cell counting methods were prepared from raw bulk milk preserved with potassium dichromate. Somatic cells were separated by centrifugation, then appropriate cell dilutions were prepared in the dichromate-preserved skim milk. Somatic cell counts from SCCS stored at 4°C were stable over a 23-wk period. No bacterial contamination was detected in these samples. In a collaborative study among eight laboratories, SCCS were not affected by usual conditions by shipping. The SCCS can be used as reference standards for the direct microscopic somatic cell count and the Fossomatic and Coulter Counter somatic cell counting methods.

1987 ◽  
Vol 50 (2) ◽  
pp. 132-135 ◽  
Author(s):  
T. J. LINTNER ◽  
A. L. LANGE ◽  
C. W. HEALD ◽  
R. J. EBERHART

Somatic cell count samples (SCCS) for use in comparison of milk somatic cell counting methods were prepared from the cell sediment deposited in a creamery milk separator. Bovine milk somatic cells were resuspended from the sediment, and serial cell dilutions were prepared in bronopol-preserved milk diluent. Over a 1-year period, sets of SCCS were prepared each month and sent to milk-testing laboratories in the U.S.A., Canada and Europe, and counted by the methods in use at those Laboratories: (a) direct microscopic somatic cell count (DMSCC), (b) Fossomatic counter and (c) Coulter counter. Cell counts were normalized to eliminate the effect of month to month variation in the cell content of the SCCS. Counts obtained by the three methods were similar, although Coulter counter results tended to be lower, and significantly lower (P< 0.05) in SCCS with cell counts greater than 700,000 cells/ml than those counts by the other two methods. The effect of shipping on SCCS stability was assessed for SCCS samples sent to and returned from other laboratories, and counted by the Fossomatic method on their return. Counts were similar before and after shipping, except that results for SCCS with cell counts greater than 1,000,000 cells/ml were significantly higher (P<0.05) after their return.


1981 ◽  
Vol 48 (3) ◽  
pp. 393-403 ◽  
Author(s):  
Richard F. Sheldrake ◽  
Roderic J. T. Hoare ◽  
Victoria E. Woodhouse

SummaryThe prevalence of intramammary infection in 4 commercial goat herds was studied in conjunction with electronic somatic cell count and volume analysis, determined using a Coulter Counter and volume analyser.Neither streptococci nor mycoplasma were isolated from any half and the prevalence of intramammary infection with Staphylococcus aureus ranged from 0 to 3% between herds. For coagulase-negative staphylococci the range for infected halves was 36–71%. There was no significant difference between the mean total microscopic somatic cell count for halves infected with coagulase-negative staphylococci and those free from infection. A similar trend was observed for electronic somatic cell counts although the mean electronic cell count was greater than the mean total microscopic count on the 2 occasions that they were compared. The correlation coefficients between the 2 cell counting methods were 0·86 and 0·94. Between herds there were significant differences in mean electronic somatic cell count, with herd means ranging from 438×103 to 1684×103 cells/ml. In 2 of the 4 herds studied, milk samples from halves infected with coagulase-negative staphylococci had a significantly higher prevalence of cell volume distributions with a modal cell volume between 65 µ3 and 100 µ3. This was attributed to a higher proportion of polymorphonuclear neutrophils.Use of electronic somatic cell count and cell volume analysis were considered of little value in predicting infection caused by coagulase-negative staphylococci as there was a high proportion of false negative and false positive predictions.


2011 ◽  
Vol 78 (4) ◽  
pp. 436-441 ◽  
Author(s):  
Maddalena Zucali ◽  
Luciana Bava ◽  
Alberto Tamburini ◽  
Milena Brasca ◽  
Laura Vanoni ◽  
...  

The aim of the study was to investigate the effects of season, cow cleanliness and milking routine on bacterial and somatic cell counts of bulk tank milk. A total of 22 dairy farms in Lombardy (Italy) were visited three times in a year in different seasons. During each visit, samples of bulk tank milk were taken for bacterial and somatic cell counts; swabs from the teat surface of a group of cows were collected after teat cleaning and before milking. Cow cleanliness was assessed by scoring udder, flanks and legs of all milking cows using a 4-point scale system. Season affected cow cleanliness with a significantly higher percentage of non-clean (NC) cows during Cold compared with Mild season. Standard plate count (SPC), laboratory pasteurization count (LPC), coliform count (CC) and somatic cell count, expressed as linear score (LS), in milk significantly increased in Hot compared with Cold season. Coagulase-positive staphylococci on teat swabs showed higher counts in Cold season in comparison with the other ones. The effect of cow cleanliness was significant for SPC, psychrotrophic bacterial count (PBC), CC and Escherichia coli in bulk tank milk. Somatic cell count showed a relationship with udder hygiene score. Milking operation routine strongly affected bacterial counts and LS of bulk tank milk: farms that accomplished a comprehensive milking scheme including two or more operations among forestripping, pre-dipping and post-dipping had lower teat contamination and lower milk SPC, PBC, LPC, CC and LS than farms that did not carry out any operation.


2009 ◽  
Vol 76 (3) ◽  
pp. 326-330 ◽  
Author(s):  
Olga Wellnitz ◽  
Marcus G Doherr ◽  
Marta Woloszyn ◽  
Rupert M Bruckmaier

Determination of somatic cell count (SCC) is used worldwide in dairy practice to describe the hygienic status of the milk and the udder health of cows. When SCC is tested on a quarter level to detect single quarters with high SCC levels of cows for practical reasons, mostly foremilk samples after prestimulation (i.e. cleaning of the udder) are used. However, SCC is usually different in different milk fractions. Therefore, the goal of this study was the investigation of the use of foremilk samples for the estimation of total quarter SCC. A total of 378 milkings in 19 dairy cows were performed with a special milking device to drain quarter milk separately. Foremilk samples were taken after udder stimulation and before cluster attachment. SCC was measured in foremilk samples and in total quarter milk. Total quarter milk SCC could not be predicted precisely from foremilk SCC measurements. At relatively high foremilk SCC levels (>300×103 cells/ml) foremilk SCC were higher than total quarter milk. At around (50–300)×103 cells/ml foremilk and total quarter SCC did not differ considerably. Most interestingly, if foremilk SCC was lower than 50×103 cells/ml the total quarter SCC was higher than foremilk SCC. In addition, individual cows showed dramatic variations in foremilk SCC that were not very well related to total quarter milk SCC. In conclusion, foremilk samples are useful to detect high quarter milk SCC to recognize possibly infected quarters, only if precise cell counts are not required. However, foremilk samples can be deceptive if very low cell numbers are to be detected.


1977 ◽  
Vol 40 (10) ◽  
pp. 671-675 ◽  
Author(s):  
N. WANG ◽  
G. H. RICHARDSON

Milk sample preparation for Optical Somatic Cell Counter II operation was simplified by using a diluter to add fixative, mix, and dilute samples. Potassium dichromate preservative tablets produced a mean increase of 7,000 in somatic cell counts in fresh milk. Samples held at 20–23 C beyond 2 days or at 4–7 C beyond 4 days showed a reduction in somatic cell count. The mean somatic cells in 3 Holstein herds tested over a 6-month period was 3.8 × 105/ml. A 22-month survey of 52.6 thousand Utah Dairy Herd Improvement samples which were shipped under ambient conditions and then held at 5 C until tested, indicated 75% below 400,000 and 2.7% above 1.6 million somatic cells/ml. Casein, noncasein protein, total protein, fat and milk weight data were also obtained on the three herds. Multiple correlations were obtained. The best correlations suggested that testing for total protein and somatic cells in a central laboratory would estimate casein and noncasein protein. Such tests are most valuable for the cheese industry.


1972 ◽  
Vol 35 (10) ◽  
pp. 582-584 ◽  
Author(s):  
W. C. Lawton ◽  
V. S. Packard

For this investigation, 2,673 dairy herds supplying milk to the Minneapolis-St. Paul market were divided into three study groups consisting of 681, 684, and 1,308 herds. All milk supplies were analyzed monthly by the catalase test and confirmatory microscopic evaluation was made on all samples showing 20% or higher oxygen. The study groups were treated as follows: Group I producers received no reports of tests made on their milk supplies and no field work was done; Group II producers were sent reports of tests, but no field work was done; Group III received reports of tests and where high somatic cell counts were observed, a fieldman assigned to the project made farm visits, assisted the producer where possible and filed a work sheet report on milking equipment condition and milking practices. Data were collected for slightly under two years, between August, 1969 and February, 1971. A total of 30,645 catalase determinations was made. Of these, 4,875 ( 15.9%) showed 20% oxygen and higher and 2,084 (6.8%) showed 30% and higher. In the latter group, 368 (1.2% of all samples) were confirmed by the microscopic method at 1.5 million or higher somatic cell count. By study group, the percentages of samples confirmed at 1.5 million or higher somatic cell count (for all catalase tests of 20% or higher) were 1.2, 1.4, and 1.5%, respectively. Using 1.5 million or higher somatic cell count as an actionable level, actionable cases by study group were 11.3, 10.4, and 12.0%, respectively. Lastly, considering three out of five actionable level counts as a basis for suspending permits, the percent of potential suspensions, by study group, were 0.14, 0.73, and 0.91%, respectively.


1976 ◽  
Vol 39 (12) ◽  
pp. 854-858 ◽  
Author(s):  
D. R. THOMPSON ◽  
V. S. PACKARD ◽  
R. E. GINN

The Direct Miscroscopic Somatic Cell Count — field method (DMSCC), Wisconsin Mastitis Test (WMT), and Electronic Somatic Cell Count (ESCC) were studied to determine variability and relationship to each other. The coefficients of variation computed at a DMSCC count near one million were 15.6% (DMSCC), 6.3% (WMT), and 4.2% (ESCC). Linear regression equations were determined for predicting DMSCC results by WMT and ESCC. The approximate width of the 95% confidence intervals for ESCC predicting DMSCC were ± 275,000 and for WMT predicting DMSCC were ± 600,000. The prediction of square root and log transformations of DMSCC by WMT exhibited narrower confidence intervals for low somatic cell counts, but wider intervals for high counts (greater than 1,000,000).


1980 ◽  
Vol 47 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Ali E. Ali ◽  
Anthony T. Andrews ◽  
Gordon C. Cheeseman

SummaryThe effects of increased somatic cell count, whether caused by infection or by experimental infusion of bacterial endotoxin, on the distribution in milk of caseins between the micellar and soluble forms were investigated. The relationship of somatic cell count to some cheese-making parameters was also studied. With quite modestly elevated cell counts (2–3 × 106/ml) increases of up to 37% in total casein in the soluble phase were observed, most of which was contributed by β-casein, while κ- and αs1-caseins increased only slightly. With storage at 4°C, the concentrations of all the caseins, Ca and phosphate in the soluble phase increased substantially during the first 48 h, but this was followed by a slight decline on further storage. Rennet clotting time, losses of fat in whey, curd moisture, and losses in curd yield and rigidity were all greater the higher the somatic count. Clear differences were detectable in these parameters between milks of very low cell count (e.g. 5 × 104 cells/ml) and milks with counts more typical of those found in bulk supplies (e.g. about 5 × 105 cells/ml). If these findings can be reproduced in commercial practice even a modest reduction in bulk milk somatic cell counts might be expected to bring definite benefits.


1983 ◽  
Vol 63 (4) ◽  
pp. 781-789 ◽  
Author(s):  
R. K. MOORE ◽  
J. E. MOXLEY ◽  
B. W. KENNEDY ◽  
E. B. BURNSIDE

Milking speed data were obtained for 2604 Holstein-Friesian cows, identified by sire, in test herds located in Quebec and Ontario. Milk samples were collected from each cow and analyzed for somatic cell count. Completed or projected lactation production records were available for this sample of cows. Two-minute yield and total milking time were adjusted for the effect of milk yield at sampling and the raw cell counts were transformed to the natural log scale. Sire and error variances were obtained by maximum likelihood (ML) methods and used to estimate heritabilities of and correlations between traits. The heritability estimate for the adjusted 2-min. yield, 0.23, was higher than that for the adjusted total milking time (0.13), with the estimates for the two unadjusted measures being intermediate (0.18). The phenotypic correlations between milking speed and somatic cell count were small. However, there were two distinct linear phases to the relationship between the adjusted 2-min yield and cell count. Small but significant phenotypic correlations were observed between unadjusted measures of milking speed and lactation production (0.11–0.22); however, correlations were not significant when adjustments were made for the milk yield at sampling. Genetic correlations between milking speed and somatic cell count were moderate to large and indicated an antagonistic relationship between faster milking speed and cell count. Also, the genetic correlations suggested some antagonism between increasing 2-min yield and lactation production, while the relationship between lactation traits and milking time was small. Key words: Milking speed, somatic cell count, correlations, heritabilities, Holsteins


1992 ◽  
Vol 75 (12) ◽  
pp. 3359-3366 ◽  
Author(s):  
Ynte H. Schukken ◽  
K.E. Leslie ◽  
A.J. Weersink ◽  
S.W. Martin

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