Variation in milk cell counts during lactation of British Friesian cattle

1983 ◽  
Vol 36 (3) ◽  
pp. 335-339 ◽  
Author(s):  
P. D. P. Wood ◽  
J. M. Booth

ABSTRACTA survey was carried out of 1 640 British Friesian heifers calving predominantly in the autumn of 1979. The monthly samples of 1 055 animals showing no reported evidence of udder infection were used to evaluate the parameters of a lactation curve in milk cell count. The model wasC = 190 n−0.4880exp(0·178n)where C is the monthly cell count in millions per 1 during the nth month of lactation. The cell count varied from 230 × 106 in week 1 and 190 × 106 in week 11 to 400 × 106 in week 44 of lactation.On applying the model to the whole sample, milk sampled within a month before or after antibiotic treatment for clinical mastitis contained more than 200 × 106 cells per 1 above the level suggested by the lactation curve. Lactation mean cell counts of treated cows were 400 × 106 cells per 1 higher than those of untreated cows. It was not possible to identify periods in which cows required treatment, or those with high cell counts, by reference to the lactose concentration in the milk samples. Among the untreated cows, the cell count at the third monthly test-day was lower than at any other time, and was more highly correlated with the lactation mean cell count.

1960 ◽  
Vol 27 (1) ◽  
pp. 19-32 ◽  
Author(s):  
W. H. Alexander ◽  
F. B. Leech

SummaryTen farms in the county of Durham took part in a field study of the effects of feeding and of udder disease on the level of non-fatty solids (s.n.f.) in milk. Statistical analysis of the resulting data showed that age, pregnancy, season of the year, and total cell count affected the percentage of s.n.f. and that these effects were additive and independent of each other. No effect associated with nutritional changes could be demonstrated.The principal effects of the factors, each one freed from effects of other factors, were as follows:Herds in which s.n.f. had been consistently low over a period of years were compared with herds in which s.n.f. had been satisfactory. Analysis of the data showed that about 70% of the difference in s.n.f. between these groups could be accounted for by differences in age of cow, stage of lactation, cell count and breed.There was some evidence of a residual effect following clinical mastitis that could not be accounted for by residual high cell counts.The within-cow regression of s.n.f. on log cell count calculated from the Durham data and from van Rensburg's data was on both occasions negative.The implications of these findings are discussed, particularly in relation to advisory work.


2016 ◽  
Vol 44 (04) ◽  
pp. 219-229 ◽  
Author(s):  
Ahmad Hamedy ◽  
Oliver Passarge ◽  
Axel Sobiraj ◽  
Markus Freick ◽  
Yvonne Frank ◽  
...  

Summary Objective of this study was the improvement of selected parameters of udder health by mastitis vaccination in a dairy herd with elevated bulk milk somatic cell counts and Staphylococcus (S.) aureus as predominant mastitis causing pathogen. Material and methods: On a dairy farm, pregnant heifers (status group [SG] 1; n = 181) as well as cows stratified for their udder health state (classification based on results of cytobacteriological investigations of quarter milk samples obtained before dry cow therapy [MS0]) (SG 2–4; n = 416) were randomly assigned to one of the following vaccination groups (VG): Startvac® (VG SV), Bestvac® Rind Mastitis (containing herd-specific S. aureus-strains; VG BV) and the unvaccinated control (VG Co, placebo), respectively. The collected data (5 [MS5] and 52 [MS52] days in milk [DIM]: quarter milk somatic cell count [QSCC] and bacteriological investigation of quarter milk samples; dairy herd improvement test [DHIT] days 1–10: milk yield and individual cow somatic cell count; until 305 DIM: clinical mastitis cases) were compared between the VG within their SG. Results: S. aureus prevalences were significantly lower in VG SV (p < 0.001) and VG BV (p = 0.006) within SG 3 and in VG SV (p = 0.008) within SG 4, respectively, in comparison to VG Co. Milk yields (DHIT days [p = 0.042] and 305-day milk yield [p = 0.040]) were significantly less in VG SV within SG 4 compared to VG Co. Significant different changes over time in comparison to VG Co indicating a vaccine effect during lactation were only observed for QSCC within SG 4 for VG BV (p = 0.017; increase towards MS52) and for S. aureus prevalence within SG 3 for VG BV (p < 0.001; opposing trends from MS0 towards MS52). All other interactions of time and VG under investigation were not significant in any of the SG. Furthermore, there were no descriptive differences in the incidence of clinical mastitis and duration of a necessary mastitis therapy, respectively, between the VG within their SG. Conclusion: In this field study, the application of two different mastitis vaccines was not an appropriate tool to improve the considered parameters of udder health sustainably.


Author(s):  
Wim van der Meer ◽  
Colin Stephen Scott ◽  
MarinusH. de Keijzer

AbstractThis study evaluated inter- and intra-observer variabilities of band cell and atypical lymphocyte differentials and the influence of instrument flagging information on resulting microscopic differentials. Five stained slides with a range of band cell counts and five with variable numbers of atypical lymphocytes were sent for morphological review by 30 technicians. No supplementary full blood cell count information was provided. Two months later, the same slides were sent, together with their corresponding analyzer reports comprising the full blood cell count, automated differentials and flags, to the same technicians. The first and second appraisals of band cells and variant lymphocytes both showed poor levels of inter-observer consistency. Observed values for all slides were very wide and suggested a high inherent predisposition to erroneous reporting practices. Analysis of category trends showed that analyzer left shift or immature granulocytes flags had no influence on observer band cell assessments as downward vs. upward category revisions were evenly balanced. The findings for atypical lymphocytes were, however, somewhat different. Two slides with no flags both showed balanced category revisions, whereas two of the three slides with atypical lymphocyte flags showed clear evidence of upward category revision. The third slide with an atypical lymphocyte flag did not show any overall category trend, but six of the seven observers who in the first examination recorded atypical lymphocyte estimates of ≤30% revised their estimates upward when the slides were examined the second time. These results suggest that morphologist access to an analyzer report and flagging information is unlikely to affect the “randomness” of band cell determinations but it may induce observer bias in variant lymphocyte estimates.


Author(s):  
Tvarožková ◽  
Vašíček ◽  
Uhrinčať ◽  
Mačuhová ◽  
Hleba ◽  
...  

Mastitis is a major health problem of the udder in dairy sheep breeds. For diagnosis of subclinical mastitis, somatic cell count (SCC) is commonly used. The presence of pathogens in the udder causes the increase of leukocytes and thus SCC in milk. Therefore, the aim of this study was to evaluate the presence of pathogens in the milk of ewes and the possible relationship with SCC. The changes of leukocytes subpopulation in milk samples with high SCC were evaluated as well. The experiment was carried out on a dairy farm with the Lacaune breed. This study was conducted on 45 ewes (98 milk samples) without signs of clinical mastitis. Based on somatic cell count, samples were divided to five SCC groups: SCC1 &lt; 200 000 cells/ml (45 milk samples); 200 000 ≤ SCC2 &lt; 400 000 cells/ml (10 milk samples); 400 000 ≤ SCC3 &lt; 600 000 cells/ml (six milk samples); 600 000 ≤ SCC4 &lt; 1 000 000 cells/ml (six milk samples); SCC5 ≥ 1 000 000 cells/ml (31 milk samples). No pathogens were observed in the majority of milk samples (60.20%). Coagulase-negative staphylococci (CNS) were the most commonly isolated pathogens from the milk of ewes (86.11%). Staphylococcus epidermidis had the highest incidence from CNS (35.48%). In the SCC5 group, up to 79.31% of bacteriological samples were positive. The percentage of leukocytes significantly increased (P &lt; 0.001) in the samples with higher SCC (≥ 200 × 10<sup>3</sup> cells/ml) in comparison to the group SCC1. Also, the percentage of polymorphonuclear cells (PMNs) was significantly higher with increasing SCC (P &lt; 0.001). In conclusion, the presented results showed that the high SCC was caused by the presence of the pathogen in milk. Thus SCC &lt; 200 000 cells/ml and leukocyte subpopulation, especially PMNs, could be considered as important tools in udder health programs applied in dairy ewes.


1997 ◽  
Vol 1997 ◽  
pp. 25-25
Author(s):  
R A Mrode ◽  
G J T Swanson

Mastitis remains a costly health problem to dairy farmers despite a significant reduction in both clinical and sub-clinical mastitis over the last 25 years. This reduction has been due predominantly to the success of management control programmes. The continuing losses have raised the interest in breeding as a means to reduce mastitis incidence. Somatic Cell Counts (SCC) have been used since 1977 as an indirect means of monitoring mastitis within dairy herds. Since 1991 an optional individual cell count service has been offered by Milk Recording Organisations in the UK. The result is that 0.80 of recorded cows have SCC records. The Animal Data Centre has analysed the SCC data to establish genetic parameters and produced preliminary evaluations on bulls and cows (Mrode et al, 1996). As a forerunner to launching SCC evaluations it is important to determine whether SCC evaluations in the UK agree with similar evaluations overseas.


Author(s):  
Laura Jerpseth ◽  
Ketan Thakare ◽  
Zhijian Pei ◽  
Hongmin Qin

Abstract In bioprinting, biomaterials are deposited layer-by-layer to fabricate structures. Bioprinting has many potential applications in drug screening, tissue engineering, and regenerative medicine. Both animal cells and plant cells can be used to synthesize bioinks. Green bioprinting uses bioinks that have been synthesized using plant cells. Constructs fabricated via green bioprinting contain immobilized plant cells, with these cells arranged at desired locations. The constructs provide scaffolds for cell growth. Printing parameters affecting the growth of cells in green bioprinted constructs include print speed, needle diameter, extrusion temperature, and extrusion pressure. This paper reports a study to examine effects of extrusion pressure on cell growth (measured by cell count) in bioprinted constructs, using bioink containing Chlamydomonas reinhardtii algae cells. Three levels of extrusion pressure were used: 3, 5, and 7 bar. Cell counts in the bioprinted constructs were measured on the third and sixth days after bioprinting. It was found that, as extrusion pressure increased, cell count decreased on both the third and sixth days after bioprinting. Furthermore, the difference in cell counts between the third and the sixth days decreased as extrusion pressure increased. These trends suggest that increasing extrusion pressure during green bioprinting negatively affects cell growth. A possible reason for these trends is physical damage to or death of cells in the bioprinted constructs when extrusion pressure became higher.


Author(s):  
T. Kudinha ◽  
C. Simango

This study was carried out to determine the prevalence of coagulase-negative staphylococci in clinical and subclinical mastitis in commercial and small-scale farms in Zimbabwe. Thirty five quarter milk samples from clinical mastitis cases and 371 quarter milk samples from cows with subclinical mastitis were cultured for bacterial pathogens. The most frequent pathogens isolated in clinical mastitis were the enteric bacteria (31.4 %), followed by coagulase negative staphylococci (22.9 %) and then Staphylococcus aureus (17.1 %), whereas in subclinical mastitis S. aureus (34.2 %) and coagulase-negative staphylococci were (33.2 %) the most common. Bacillus species were only isolated in milk samples from subclinical mastitis. Coagulase-negative staphylococci were observed in mixed infections with other bacteria in only 2.2 % of the 406 milk samples from clinical and subclinical mastitis where they were isolated together with Bacillus species in 6 of the 9 mixed infection cases. About 95 % of the milk samples from which 131 coagulase-negative staphylococci were isolated had correspondingly high somatic cell counts. The coagulase-negative staphylococci isolated most frequently were S. chromogenes (7.9 %), S. epidermidis (7.4 %) and S. hominis (5.9 %). They were all associated with high somatic cell counts. All the coagulase-negative staphylococci isolates were susceptible to cloxacillin and erythromycin, and more than 90 %of the isolates were susceptible to neomycin, penicillin and streptomycin. The highest resistance was to tetracycline (17.6 %), followed by lincomycin (13.7 %). About 8 % of the isolates were resistant to both penicillin and streptomycin.


2003 ◽  
Vol 77 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Y. de Haas ◽  
H.W. Barkema ◽  
Y.H. Schukken ◽  
R.F. Veerkamp

AbstractGenetic associations were estimated between pathogen-specific cases of clinical mastitis (CM), lactational average somatic cell score (LACSCS), and patterns of peaks in somatic cell count (SCC) which were based on deviations from the typical lactation curve for SCC. The dataset contained test-day records on SCC in 94 781 lactations of 25 416 cows of different parities. Out of these 94 781 lactations, 41 828 lactations had recordings on occurrence of pathogen-specific CM and on SCC, and 52 953 lactations had recordings on SCC only. A total of 5 324 lactations with cases of CM were recorded. Analysed pathogens were Staphylococcus aureus, coagulase negative staphylococci, Escherichia coli, Streptococcus dysgalactiae, Streptococcus uberis, and culture-negative samples. Pattern definitions were based on three or five consecutive test-day recordings of SCC. They differentiated between short or longer periods of increased SCC, and also between lactations with and without recovery. Occurrence of pathogen-specific CM and presence of patterns of peaks in SCC were both scored as binary traits. Variance components for sire, maternal grandsire, and permanent animal effects were estimated using AS-REML. The estimated heritability for overall CM was 0·04, and similar heritabilities for pathogen-specific CM were estimated. Heritabilities for the patterns of peaks in SCC ranged from 0·01 to 0·06. Heritabilities for LACSCS were 0·07 to 0·08. Genetic correlations with patterns of peaks in SCC differed for each pathogen. Generally, genetic correlations between pathogen-specific CM and patterns of peaks in SCC were stronger than the correlations with LACSCS. This suggests that genetic selection purely on diminishing presence of peaks in SCC would decrease the incidence of pathogen-specific CM more effectively than selecting purely on lower LACSCS.


1979 ◽  
Vol 46 (3) ◽  
pp. 453-462 ◽  
Author(s):  
Amer M. A. Salih ◽  
Malcolm Anderson

SummaryThe effect that changes in composition which occur in milks possessing high cell counts have on milk lipolysis has been investigated. High cell counts were produced either by intramammary infusion of Escherichia coli endotoxin or Streptococcus agalactiae or by addition of washed cells which were isolated from milk obtained from quarters infused with endotoxin. Free fatty acid levels in milk were measured in terms of acid degree value (ADV) either as initial ADV measured immediately after milking or ADV developed after a prescribed incubation period.There was an increase in initial ADV after the infusion either of endotoxin or of Str. agalactiae relative to a control quarter. This increase appeared to be associated with changes in cell count, but in absolute terms the influence of cells on ADV became less as cell count increased. Neither type of infusion had any effect on lipoprotein lipase activity. The addition of washed cells to normal milk resulted in an increase in developed ADV, but the increment was not as large as that produced by the addition of 1% blood serum. When cream and skim-milk from endotoxin-treated quarters and control quarters were mixed in different combinations with and without additional cells, developed ADV was higher in those samples containing endotoxin cream and those with added cells. Milk from a quarter treated with endotoxin was diluted with its own skim-milk to produce different cell counts and ADV was determined after various time intervals at 4 and 37 °C. Lipolysis increased with increasing cell count, but a depression in lipolytic rate was noted after incubation for 6 h at 4 °C and 20 min at 37 °C.The proportion of skim-milk lipoprotein lipase activity in milk serum was larger both in milks possessing high cell counts and in normal milk adjusted to between 5 and 20 mM-NaCl by addition of solid NaCl. These levels of NaCl inhibited lipolysis.The possible direct and indirect effects of high cell count on milk lipolysis are discussed.


1980 ◽  
Vol 60 (2) ◽  
pp. 231-239 ◽  
Author(s):  
SUSAN HIGGINS ◽  
R. K. MOORE ◽  
B. W. KENNEDY

Teat conformation characteristics were measured on 402 Holstein-Friesian cows in 18 dairy herds in western Quebec and eastern Ontario. The purpose of the study was to determine the effects of heridity on teat conformation traits as well as to examine phenotypic relationships between the traits and somatic cell count as a measure of udder health. Maximum likelihood estimates of heritabilities of teat conformation traits and cell count, transformed to a log scale, were low; usually less than 0.10. Exceptions were length of front teat (h2 = 0.44) and distance of udder to the floor (h2 = 0.41). Significantly higher cell counts were associated with teats that were long, wide, not plumb and bottle (as opposed to cylindrical or funnel) shaped. The most highly correlated trait with cell count was distance of udder to the floor (r = − 0.24). However, many of the significant gross relationships observed were jointly related with age of cow, and when the effects of age of cow at calving, stage of lactation and herd were removed, only length of rear teat and front and rear teat medial diameters had significant influences on cell count.


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