Genetic and economic relationships between somatic cell count and clinical mastitis and their use in selection for mastitis resistance in dairy cattle

2001 ◽  
Vol 73 (1) ◽  
pp. 19-28 ◽  
Author(s):  
H. N. Kadarmideen ◽  
J. E. Pryce
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Genetic Parameters ◽  
Clinical Mastitis ◽  
Parameter Estimates ◽  
Data Set ◽  
Selection For ◽  
Genetic Regression ◽  
Genetic Responses

AbstractClinical mastitis (CM) and monthly test-day somatic cell count (SCC) records on Holstein cows were used to investigate the genetic and economic relationship of lactation average (of natural logarithms of) monthly test-day SCC (LSCC) with CM. After editing, there were 23663 lactation records on 17937 cows from 257 herds. Three groups of herds were first identified as having low (L), medium (M) and high (H) incidences of CM from the original or pooled (P) data set. Genetic parameters were estimated for the original and three data sub-sets (derived from the three herd groups). Expected genetic responses to selection against CM were calculated using genetic parameters of each data set separately, with an adapted version of the UK national index (£PLI-profitable lifetime index). Indirect economic values of SCC (EVSCC) were calculated as the direct cost of CM per cow per lactation weighted by the genetic regression coefficient of CM lactation records on their sires’ predicted transmitting ability for SCC (PTASCC). All genetic regression analyses were based on linear and threshold-liability models. Heritabilities and repeatabilities, respectively, were 0034 and 0·111 for CM and 0120 and 0·347 for LSCC in the original data set. Genetic, permanent environmental, residual and phenotypic correlations between CM and LSCC for the original (pooled) data set were 0·70, 0·44, 013 and 0·20, respectively. Parameter estimates for the three herd groups differed, with magnitude of the estimates increasing with increase in incidence from L to H herd groups. The EVSCCper unit of PTASCCfor L, M, H and P herd groups, respectively, were £004, £0·15, £0·33 and £018 on the observed and £0·86, £0·96, £1·22 and £110 on the underlying-liability scales. Selection for mastitis resistance, using SCC as an indicator trait in an extended version of £PLI, resulted in a selection response of 0·9, 21, 1·7 and 1·9 more cases per 100 cows after 10 years of selection in L, M, H and P herd groups, respectively. These results suggest that genetic responses to selection for CM resistance as well as the EVSCCare specific to herd incidence and hence would be appropriate for customized selection indexes. The increase in CM cases was greater when CM was excluded from the £PLI (2·8v1·9), hence it is recommended that CM should be included in the breeding goal in order to arrest further decline or to make improvement in genetic resistance to clinical mastitis.

scholarly journals Genetic Parameters for Somatic Cell Count, Logscc and Somatic Cell Score of Breeds: Improved Valachian, Tsigai, Lacaune and their Crosses/Genetski Parametri Za Broj Somatskih Ćelija, Logscc I Skor Somatskih Ćelija Kod Rasa: Poboljšana Vlaška, Cigaja, Lakon I Njihovih Meleza

2014 ◽  
Vol 64 (3) ◽  
pp. 386-396 ◽  
Author(s):  
Makovický Pavol ◽  
Makovický Peter ◽  
Nagy Melinda ◽  
Rimárová Kvetoslava ◽  
Diabelková Jana
Keyword(s):  
Animal Model ◽  
Maximum Likelihood ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Genetic Parameters ◽  
Clinical Mastitis ◽  
Somatic Cell Score ◽  
Primary Data ◽  
Dairy Sheep

Abstract In the last few years there has been increasing emphasis on reducing milk somatic cell count to improve the milk quality in dairy ruminants. Genetic parameters for somatic cell count (SCC), LOGSCC and somatic cell score (SCS) were estimated. About 1193 measurements were included in the analysis for each character of 358 ewes of 9 genotypes. Nine breeds and genotypes were included in these experiments: purebred Improved Valachian (IV), Tsigai (T), Lacaune (LC) ewes, and IV and T crosses with a genetic portion of Lacaune and East Friesian (EF) - 25 %, 50 % and 75 %. Primary data were processed using restricted maximum likelihood (REML) methodology and the multi-trait animal model, using programs REMLF90 and VCE 4.0. Heritability coefficients for somatic cell count were low: h2=0.03, for LOGSCC h2= 0.08 and for somatic cell score h2=0.06. Somatic cell score can be considered for inclusion in a breeding program aimed at reducing somatic cell count and frequency of clinical mastitis in dairy sheep.

Udder and teat conformational risk factors for elevated somatic cell count and clinical mastitis in New York Holsteins

2019 ◽  
Vol 163 ◽  
pp. 7-13 ◽  
Author(s):  
Asha M. Miles ◽  
Jessica A.A. McArt ◽  
Francisco A. Leal Yepes ◽  
Cassandra R. Stambuk ◽  
Paul D. Virkler ◽  
...  
Keyword(s):  
Risk Factors ◽  
New York ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Clinical Mastitis

scholarly journals The presence of pathogens in milk of ewes in relation to the somatic cell count and subpopulations of leukocytes

2021 ◽  
Author(s):  
Tvarožková ◽  
Vašíček ◽  
Uhrinčať ◽  
Mačuhová ◽  
Hleba ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Dairy Farm ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Polymorphonuclear Cells ◽  
Coagulase Negative Staphylococci ◽  
Major Health Problem ◽  
Milk Samples

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.

scholarly journals Genetic associations for pathogen-specific clinical mastitis and patterns of peaks in somatic cell count

2003 ◽  
Vol 77 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Y. de Haas ◽  
H.W. Barkema ◽  
Y.H. Schukken ◽  
R.F. Veerkamp
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Clinical Mastitis ◽  
Genetic Associations ◽  
Coagulase Negative Staphylococci ◽  
Streptococcus Uberis ◽  
Lactation Curve

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.

Relationship between somatic cell count status and subsequent clinical mastitis in Dutch dairy cows

2011 ◽  
Vol 102 (4) ◽  
pp. 265-273 ◽  
Author(s):  
B.H.P. van den Borne ◽  
J.C.M. Vernooij ◽  
A.M. Lupindu ◽  
G. van Schaik ◽  
K. Frankena ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Clinical Mastitis

Reliability of the bulk milk somatic cell count as an indication of average herd somatic cell count

2009 ◽  
Vol 76 (4) ◽  
pp. 490-496 ◽  
Author(s):  
Jan Lievaart ◽  
Herman W Barkema ◽  
Henk Hogeveen ◽  
Wim Kremer
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Management Practices ◽  
Dairy Herd ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Bulk Milk ◽  
Sampling Variation ◽  
The Difference

Bulk milk somatic cell count (BMSCC) is a frequently used parameter to estimate the subclinical mastitis prevalence in a dairy herd, but it often differs considerably from the average SCC of all individual cows in milk. In this study, first the sampling variation was determined on 53 dairy farms with a BMSCC ranging from 56 000 to 441 000 cells/ml by collecting five samples on each farm of the same bulk tank. The average absolute sampling variation ranged from 1800 to 19 800 cells/ml. To what extent BMSCC represents all lactating cows was evaluated in another 246 farms by comparing BMSCC to the average herd SCC corrected for milk yield (CHSCC), after the difference was corrected for the sampling variation of BMSCC. On average BMSCC was 49 000 cells/ml lower than CHSCC, ranging from −10 000 cells/ml to 182 000 cells/ml, while the difference increased with an increasing BMSCC. Subsequently, management practices associated with existing differences were identified. Farms with a small (<20%) difference between BMSCC and CHSCC administered intramuscular antibiotics for the treatment of clinical mastitis more often, used the high SCC history when cows were dried off more frequently and had a higher number of treatments per clinical mastitis case compared with farms with a large (⩾20%) difference. Farms feeding high-SCC milk or milk with antibiotic residues to calves were 2·4-times more likely to have a large difference. Although sampling variation influences the differences between BMSCC and CHSCC, the remaining difference is still important and should be considered when BMSCC is used to review the average herd SCC and the subclinical mastitis prevalence.

Associations between somatic cell count patterns and the incidence of clinical mastitis

2005 ◽  
Vol 67 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Y. de Haas ◽  
H.W. Barkema ◽  
Y.H. Schukken ◽  
R.F. Veerkamp
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Clinical Mastitis
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