scholarly journals Effective Use of Dairy Herd Improvement Somatic Cell Counts in Mastitis Control

1986 ◽  
Vol 69 (6) ◽  
pp. 1708-1720 ◽  
Author(s):  
Jeffrey K. Reneau
1977 ◽  
Vol 40 (7) ◽  
pp. 490-492 ◽  
Author(s):  
G. M. JONES ◽  
C. W. HEALD ◽  
W. N. PATTERSON ◽  
D. E. ROBINSON

The Fossomatic determination of somatic cells present in individual cow milk samples was instituted in the Virginia Dairy Herd Improvement testing program in June, 1976. During the first 6 months the average count was 449,060 cells/ml for 113,735 observations. The average percentage of cows according to ranges in cell counts was: under 150,000, 47.9%; 150–400,000, 25.8%; 400–800,000, 12.5%; 800–1,500,000, 7.2%; and over 1,500,000, 6.6%. The percentage of cows with less than 150,000 cells/ml was reduced for September, 1976. On a herd basis, 66% averaged less than 500,000 cells/ml, 30% between 500 to 1,000,000, and 4% exceeded 1,000,000. The percentage of herds with less than 500,000 cells/ml decreased from June to September, 1976 but increased in October. Quarters infected with primary pathogens were estimated by Westgarth's equation to be 10.4% resulting in a calculated 5% reduction in total herd milk production. Procedures are described which would assist dairymen in the interpretation of somatic cell counts.


1976 ◽  
Vol 59 (6) ◽  
pp. 1119-1123 ◽  
Author(s):  
G.W. Bodoh ◽  
W.J. Battista ◽  
L.H. Schultz ◽  
R.P. Johnston

2006 ◽  
Vol 74 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Anne Cathrine Whist ◽  
Olav Østerås

Data from 350 herds enrolled in the Norwegian Dairy Herd Recording System (NDHRS) were used to investigate the associations between the first two cow-milk somatic cell counts (SCC) test-days’ results after calving or the three last SCC test-days prior to drying off in the first lactation and the hazard ratio (HR) of clinical mastitis (CM) during the remaining first or the subsequent second lactation respectively. Altogether, 9519 first lactations and 6046 second lactations were included. Cox regression analyses adjusted for herd frailty effect were used. In the first lactation, SCC>40000 cells/ml on the first or second test-day was significantly associated with an increased risk of a CM event in the remaining first lactation. HR, compared with 10000 cells/ml, increased from 1·6 (1·4) for SCC of 40000–60000 cells/ml to 6·9 (4·2) for SCC >800000 cells/ml, when using the first (second) SCC test-day in the first lactation. Cows with a geometric mean of the three last SCC test-days between 50000 and 100000 cells/ml and between 401000 and 800000 cells/ml in the first lactation had HR of CM during the second lactation of 1·3 and 2·8 respectively compared with a reference group of 10000–20000 cells/ml. If a CM episode in the first lactation occurred, the HR for having a CM event during the second lactation was 1·5. There was a significant frailty effect which disappeared if the incidence rate of CM at herd level was included in the model.


1995 ◽  
Vol 1995 ◽  
pp. 128-128 ◽  
Author(s):  
R A Mrode ◽  
G J T Swanson ◽  
M S Winters

Mastitis constitutes a major source of economic loss in the national dairy herd. Although good management practices can produce a major reduction in mastitis, there is considerable interest in the reduction of mastitis through breeding. Somatic cell counts (SCC) have been used as a way of indirectly measuring sub-clinical mastitis within a herd. Since 1991, average cell count is obtained for all herds and this is used to adjust milk payments.Milk recording organisations introduced a cow cell count service in 1990. The data are now available for the preliminary analysis of the usefulness of somatic cell counts. The objective of this study was to estimate genetic parameters for SCC for three major breeds in the UK.


Livestock ◽  
2008 ◽  
Vol 13 (3) ◽  
pp. 47-48
Author(s):  
James Hanks ◽  
Andrew Biggs BVSc MRCVS

1997 ◽  
Vol 64 (1) ◽  
pp. 13-22 ◽  
Author(s):  
TIMOTHY CLARKE ◽  
SIMON-PETER ANDREWS ◽  
PETER J. MOATE ◽  
CARMEL A. POLLINO ◽  
WERNER L. SCHMIDT

The Dairy Herd Improvement Fund of Victoria recently identified a requirement for a simple and inexpensive in-line sampler to enable dairy farmers to collect representative milk samples for counting somatic cells. We found that the currently available simple in-line milk samplers, when connected to standard 35 ml collection vessels, terminate sampling early in a milking, and thus provide samples that are unrepresentative of the whole milking. We showed that cell count during a milking varies greatly, tending to be high for the first 1–2 l. Analyses of resulting samples will thus tend to overestimate cell counts if samplers are used in their traditional way. We found greater sampling rates in high-line compared with low-line milking systems, and consequently developed modified samplers suitable for both situations. Our samplers utilize low sampling rates (∼1–3%) and large collection vessels (450 ml). Compared with currently available simple in-line samplers, our type of sampler provided milk samples considerably more representative of the entire milking for the majority of cows. In conjunction with subsampling, they provided samples of appropriate size (12·5 ml minimum to 25 ml maximum) for testing fat, protein, lactose and cell count. Cell count results indicated that errors associated with the use of currently available simple in-line samplers could frequently be >200%. In contrast, we found that use of our samplers gave an estimate for cell count that was only slightly higher (mean 20%) than that from samples collected by an approved Tru-Test sampler.


1969 ◽  
Vol 93 (3-4) ◽  
pp. 239-254
Author(s):  
Jaime E. Curbelo ◽  
José Pantoja ◽  
Angel A. Custodio ◽  
Ernesto Riquelme ◽  
Raúl Macchiavelli

Data from 302,995 test day records of individual cows of the Puerto Rico Dairy Herd Improvement Program (PRDHIP) and from 8,833 bulk tank results from all herds in Puerto Rico during the years 2004 and 2005 were analyzed for determining the potential effect of implementation of the National Mastitis Council's (NMC) proposal to reduce the present regulatory upper limit for somatic cell count of 750,000 cells/ml of crude milk. Means of herd test day milk yield per cow and of somatic cell scores on the linear scale for this data set were 17.2 kg and 3.9, respectively. On the basis of PRDHIP data, it was estimated that 20% of individual test day values, equivalent to 920,290 kg of raw milk, would exceed the upper limit if it were established at 600,000 cells/ml. The months of highest average milk production were February, March and May (18.4,18.2 and 18.2 kg/day, respectively).The lowest production was observed in August, September and October (16.3,15.6 and 15.8 kg/day, respectively). The months with the lowest average somatic cell score were February and April (both at 3.5) and those of the highest were August, September and October (4.2,4.2 and 4.3, respectively). The average somatic cell counts for herds enrolled or not enrolled in DHIP were similar (461,656 and 473,096, respectively; P greater than 0.05).


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