Genetic parameters of pathogen-specific incidence of clinical mastitis in dairy cows

2002 ◽  
Vol 74 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Y. de Haas ◽  
H. W. Barkema ◽  
R. F. Veerkamp
Keyword(s):  
Milk Yield ◽  
Selection Index ◽  
Genetic Correlations ◽  
Relative Weight ◽  
Clinical Mastitis ◽  
Coagulase Negative Staphylococci ◽  
Data Set ◽  
E Coli ◽  
Streptococcus Uberis ◽  
Current Selection

AbstractData from 274 Dutch herds recording clinical mastitis (CM) over an 18-month period were used to quantify the genetic variation for overall and pathogen-specific CM. Analysed pathogens were Staphylococcus aureus, coagulase negative staphylococci (CNS), Escherichia coli, Streptococcus dysgalactiae, Streptococcus uberis and other streptococci. The data set contained 47 563 lactations of 28 695 cows of different parities. Cases of overall and pathogen-specific CM were treated as all-or-none traits. Variance components for the sire, maternal grandsire and permanent environmental effect were estimated using generalized linear mixed models with a logit link function for the binary traits. Average number of days at risk and in milk on trial was 198 days. The estimated heritability for overall CM was 0·04, and similar heritabilities for the pathogen-specific CM were estimated. Repeatability across lactations was low for overall and pathogen-specific CM (0·10 to 0·14). Genetic correlations with milk yield and somatic cell score (SCS) differed according to pathogen. For instance, the incidence rate of clinical E. coli mastitis was slightly unfavourably correlated with milk yield at 150 days (0·13) but stronger with SCS (0·74). Whereas, the genetic correlations with clinical Str. dysgalactiae mastitis were 0·70 and 0·16, respectively. The expected correlated responses showed that current selection practices (using milk yield and SCS) will be effective in reducing the incidence of E. coli and CNS but less effective in reducing the incidence of S. aureus and Str. dysgalactiae, even with a large relative weight for SCS in the selection index.

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.

scholarly journals Heritability of Teat Condition in Italian Holstein Friesian and Its Relationship with Milk Production and Somatic Cell Score

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2271
Author(s):  
Francesco Tiezzi ◽  
Antonio Marco Maisano ◽  
Stefania Chessa ◽  
Mario Luini ◽  
Stefano Biffani
Keyword(s):  
Dairy Cattle ◽  
Somatic Cell ◽  
Milk Yield ◽  
Genetic Factors ◽  
Genetic Correlations ◽  
Somatic Cell Score ◽  
Cattle Industry ◽  
Holstein Friesian ◽  
Selection For ◽  
Current Selection

In spite of the impressive advancements observed on both management and genetic factors, udder health still represents one of most demanding objectives to be attained in the dairy cattle industry. Udder morphology and especially teat condition might represent the first physical barrier to pathogens’ access. The objectives of this study were to investigate the genetic component of teat condition and to elucidate its relationship with both milk yield and somatic cell scores in dairy cattle. Moreover, the effect of selection for both milk yield and somatic cell scores on teat condition was also investigated. A multivariate analysis was conducted on 10,776 teat score records and 30,160 production records from 2469 Italian Holstein cows. Three teat scoring traits were defined and included in the analysis. Heritability estimates for the teat score traits were moderate to low, ranging from 0.084 to 0.238. When teat score was based on a four-classes ordinal scoring, its genetic correlation with milk yields and somatic cell score were 0.862 and 0.439, respectively. The scale used to classify teat-end score has an impact on the magnitude of the estimates. Genetic correlations suggest that selection for milk yield could deteriorate teat health, unless more emphasis is given to somatic cell scores. Considering that both at national and international level, the current selection objectives are giving more emphasis to health traits, a further genetic deterioration in teat condition is not expected.

Genetic analyses of profit for Australian dairy cattle

1995 ◽  
Vol 61 (1) ◽  
pp. 9-18 ◽  
Author(s):  
P. M. Visscher ◽  
M. E. Goddard
Keyword(s):  
Dairy Cattle ◽  
Milk Yield ◽  
Selection Index ◽  
Genetic Correlations ◽  
Net Income ◽  
For Profit ◽  
Holstein Friesian ◽  
Yield Trait ◽  
Dairy Bulls ◽  
Selection Of

AbstractDirect genetic evaluation of profit was investigated as an alternative to a selection index. PROFk was defined as (net income)/(food requirement) until the start of the kth lactation, for k = 2 to 6. Genetic parameters such as heritabilities and genetic correlations were estimated for profit traits for Australian Holstein-Friesian and jersey dairy cattle. Heritabilities for profit until the start of a given lactation were moderate, ranging from 0·12 (for profit until the start of the second lactation in Holsteins) to 0·31 (profit until the start of the third lactation in Jerseys). Genetic correlations between profit traits were very high, and approached unity for most pairs of traits, so that profit early and late in herd life were nearly the same trait. Genetic correlations between profit traits and stayabilities until a given lactation were high, ranging from 0·71 to 0·97. Genetic correlations between profit traits and first lactation milk yield traits were approximately 0·80 for Holsteins and 0·90 for Jerseys. A single analysis urns carried out for lifetime profit using all data, including cows that were still in the herd at the time of data collection. Heritabilities were 0·13 for Holsteins and 0·19 for Jerseys. Genetic correlations between lifetime profit and first lactation yields were high. For the selection of dairy bulls, a multivariate analysis on a milk yield trait (e.g. protein yield) and profit until the last known lactation of bulls' progeny was suggested.

scholarly journals Genetic relationship between milk dry matter and other milk traits in extended lactations of Polish Holstein cows

2010 ◽  
Vol 55 (No. 3) ◽  
pp. 91-104 ◽  
Author(s):  
K. Yazgan ◽  
J. Makulska ◽  
A. Węglarz ◽  
E. Ptak ◽  
M. Gierdziewicz
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Fixed Effects ◽  
Dry Matter ◽  
Genetic Correlations ◽  
Random Regression ◽  
Holstein Cows ◽  
Milk Traits ◽  
Data Set ◽  
The Third

The objective of this research was to examine heritabilities and genetic, phenotypic and permanent environmental relationships between milk dry matter (DM) and milk traits such as milk, fat, protein and lactose yields, milk urea nitrogen (MUN) and somatic cell score (SCS) in extended (to 395 days) lactations of Holstein cows from a big farm in Poland. The data set consisted of 78 059 test day records from the first, second and third lactations of 3 792 cows, daughters of 210 sires and 1 677 dams. Single- or two-trait random regression models were used with fixed effects of calving year, calving month, dry period and calving interval and random additive genetic and permanent environmental effects. The last two fixed effects were not included in the analysis of first lactation data. The highest values of heritabilities for all traits, except DM, were observed in the second lactation. First lactation heritabilities for all traits – except milk yield and SCS – were smaller than those in the third lactation. Lactose yield was highly heritable, with average h<SUP>2</SUP> equal to 0.25, 0.29 and 0.28 in lactations 1, 2 and 3, respectively. Heritability for DM was slightly lower than that for lactose (0.22, 0.26 and 0.28 for lactations 1, 2 and 3, respectively). In all lactations heritabilities for SCS were below 0.1. Genetic correlations between DM and milk yield (0.64–0.74) were lower than those between MUN and milk yield (0.67–0.79) as well as between lactose and milk yield (0.72–0.82). In general, DM was much more closely correlated with fat or protein yield (0.55–0.79) than with MUN or lactose (0.38–0.76). Only in the third lactation the correlation between DM and protein (0.72) was lower than between lactose and protein (0.76). For all lactations there were very high genetic correlations between DM and lactose (0.96–0.98) and high correlations between DM and MUN (0.63–0.83) and between lactose and MUN (0.70–0.85). The results suggest that further research is needed, focused on DM and its relationship with other traits in larger populations. &nbsp;

scholarly journals Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ma. Fabiola León-Galván ◽  
José E. Barboza-Corona ◽  
A. Arianna Lechuga-Arana ◽  
Mauricio Valencia-Posadas ◽  
Daniel D. Aguayo ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Bovine Mastitis ◽  
Dairy Herd ◽  
Subclinical Mastitis ◽  
Herd Size ◽  
Clinical Mastitis ◽  
Dairy Herds ◽  
Coagulase Negative Staphylococci ◽  
California Mastitis Test ◽  
Streptococcus Uberis

Thirty-two farms (n=535cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins ofBacillus thuringiensiswas tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DMP<0.01, and correlations between udder quarters from the CMT were around 0.49P<0.01. Coagulase-negative staphylococci were mainly identified, as well asStaphylococcus aureus,Streptococcus uberis,Brevibacterium stationis,B. conglomeratum, andStaphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized byBacillus thuringiensisinhibited the growth of multiantibiotic resistance bacteria such asS. agnetis,S. equorum,Streptococcus uberis,Brevibacterium stationis, andBrachybacterium conglomeratum, but they were not active againstS. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study.

scholarly journals Genetic trends for milk, fat and protein in the Zimbabwean Holstein-Friesian population from 1973 to 1994

2001 ◽  
Vol 44 (1) ◽  
pp. 23-32
Author(s):  
K. Kunaka ◽  
S. M. Makuza ◽  
C. B. A. Wollny ◽  
J. W. Banda
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Selection Index ◽  
Milk Composition ◽  
Small Population ◽  
Data Sets ◽  
Data Set ◽  
Quadratic Effects ◽  
Genetic Trends

Abstract. Genetic trends based on 30 395 records with parities 1 to 8 were estimated using average information restricted maximum likelihood algorithm (AIREML), which had overall mean, herd, month of calving, year of birth, parity and linear and quadratic effects of days in milk. Due to changes in the Zimbabwean milk recording system data set was split into records of cows born from 1973 to 1989 and the other from 1987 to 1994. The first data set was further split into even numbered herds (EVNH73) and odd numbered herds (ODNH73), due to computational limitations. The highest milk production was from May to August. Peak milk production was observed in parity 4. The heritabilities for FCM (0.22 to 0.26), fat percent (0.24 to 0.28) and protein percent (0.21) were comparable to literature values. The annual genetic trends of FCM ranged from 8.36 kg to 13.2 kg, fat per cent ranged from 0.0 % to −0.008 % and protein per cent was −0.003 % in the three data sets. Genetic trends for milk yield, fat and protein yield were also positive but overally lower than in most other countries. The positive genetic trends obtained for milk, fat and protein yields imply that some progress has been made in increasing the milk production despite the relatively small population and significant restrictions. There is need to develop a selection index to improve milk yield and milk composition.

scholarly journals Genetic parameters for milk production and persistency in the Iranian Holstein population by the multitrait random regression model

2014 ◽  
Vol 57 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Khabat Kheirabadi ◽  
Sadegh Alijani
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Genetic Correlations ◽  
Random Regression ◽  
Genetic Dissection ◽  
Production Traits ◽  
Data Set ◽  
Random Regression Model ◽  
Regression Test ◽  
Fat Yield

Abstract. For genetic dissection of milk, fat, and protein production traits in the Iranian primiparous Holstein dairy cattle, records of these traits were analysed using a multitrait random regression test-day model. Data set included 763 505 test-day records from 88 204 cows calving since 1993. The (co)variance components were estimated by Bayesian method. The obtained results indicated that as in case of genetic correlations within traits, genetic correlations between traits decrease as days in milk (DIM) got further apart. The strength of the correlations decreased with increasing DIM, especially between milk and fat. Heritability estimates for 305-d milk, fat, and protein yields were 0.31, 0.29, and 0.29, respectively. Heritabilities of test-day milk, fat, and protein yields for selected DIM were higher in the end than at the beginning or the middle of lactation. Heritabilities for persistency ranged from 0.02 to 0.24 and were generally highest for protein yield (0.05 to 0.24) and lowest for fat yield (0.02 to 0.17), with milk yield having intermediate values (0.06 to 0.22). Genetic correlations between persistency measures and 305-d production were higher for protein and milk yield than for fat yield. The genetic correlation of the same persistency measures between milk and fat yields averaged 0.76, and between milk and protein yields averaged 0.82.

Investigation into the production and conformation traits associated with clinical mastitis using artificial neural networks

2000 ◽  
Vol 80 (3) ◽  
pp. 415-426 ◽  
Author(s):  
X. Z. Yang ◽  
R. Lacroix ◽  
K. M. Wade
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Milk Yield ◽  
Predictive Ability ◽  
Dairy Herd ◽  
Clinical Mastitis ◽  
Neural Nets ◽  
Sensitivity Analyses ◽  
Data Set ◽  
Artificial Neural

A data set comprising milk-recording and conformation data was used to investigate the usefulness of artificial neural networks in detecting influential variables in the prediction of incidences of clinical mastitis. Specifically, these data contained test-day records from dairy herd analysis, phenotypic cow scores for conformation and genetic conformation proofs for cows and their sires. The data were analysed using the milk-recording data only, the conformation data only, and a combination of the two. Results from sensitivity analyses, performed with trained neural nets, indicated that stage of lactation, milk yield on test day, cumulative milk yield and somatic cell count were the major production factors influencing the ability to detect the occurrence of clinical mastitis. Among the conformation traits, such variables as phenotypic scores for rear-teat placement, dairy character and size, cow proof for dairy character, sire reliability for final score and sire proofs for pin-setting (desirability) and loin strength were found to have some influence on the network's predictive ability, although they were all very minor in relation to the production variables mentioned. As a group, cow genetic proofs seemed more important than either sire genetic proofs or cow phenotypic scores. Given the neural network's general abilities to determine the major factors related to the presence or absence of mastitis on a given test day, it may be appropriate to investigate the possibility of using this technology for actual prediction purposes. Key words: Artificial neural networks, clinical mastitis, milk-recording data, conformation traits, sensitivity analysis, milk production

scholarly journals Genetic correlations of clinical mastitis and feet and legs problems with milk yield type traits in Dutch Black and White dairy cattle

1994 ◽  
Vol 42 (4) ◽  
pp. 371-378
Author(s):  
A.F. Groen ◽  
I. Hellinga ◽  
J.K. Oldenbroek
Keyword(s):  
Dairy Cattle ◽  
Milk Yield ◽  
Disease Incidence ◽  
Genetic Correlations ◽  
Selection Criterion ◽  
Clinical Mastitis ◽  
Direct Selection ◽  
Black And White ◽  
Continuous Scale ◽  
Type Traits

Direct selection for decreased disease incidence is difficult given low hsuperscript 2s and the absence of disease recording. Genetic correlations between diseases and type traits indicate possibilities for indirect selection; however, correlations often include experimentally instead of routinely scored type traits. The aim of this study was to estimate genetic correlations of clinical mastitis and feet and legs problems with milk yield and routinely scored type traits in Dutch Black and White [DBW; Dutch Black Pied] cows. From 1983 to 1991, the incidence of diseases was recorded at 44 farms with DBW dairy cattle. Records on 3617 cows sired by 224 bulls were analysed. Heritabilities for milk yield, type traits and diseases were obtained using an equal design multivariate Restricted Maximum Likelihood procedure considering all observations on a continuous scale. A bivariate threshold procedure was used to estimate hsuperscript 2s of diseases and genetic correlations of diseases with milk yield and type traits. Genetic correlations of clinical mastitis and feet and legs problems with milk yield were 0.16 and 0.26 respectively, and hsuperscript 2s for diseases were low 0.01-0.11. Unexpected positive relations between udder type traits and clinical mastitis were found (0.09-0.26), and possible reasons are discussed. Genetic correlations between type traits for feet and legs and problems of the feet and legs were negative -0.01 and -0.24 respectively. Final score for feet and legs could be used as a selection criterion to select to reduce the incidence of feet and legs problems.

Associations of the first occurrence of pathogen-specific clinical mastitis with milk yield and milk composition in dairy cows

2018 ◽  
Vol 85 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Mitsunori Kayano ◽  
Megumi Itoh ◽  
Nobuyuki Kusaba ◽  
Osamu Hayashiguchi ◽  
Katsuya Kida ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Milk Composition ◽  
Clinical Mastitis ◽  
Coagulase Negative Staphylococci ◽  
First Occurrence ◽  
Milk Urea ◽  
Calving Season ◽  
Autoregressive Correlation ◽  
Clinical Records

The aim of this study was to estimate the associations of the first occurrence of pathogen-specific clinical mastitis (CM) with milk yield and milk composition (somatic cell count (SCC), lactose, fat, protein content in milk and milk urea nitrogen (MUN)). We studied 3149 dairy cows in 31 Hokkaido dairy farms in Japan. Five pathogen groups were studied: Streptococcus spp.; Staphylococcus aureus (S. aureus); coagulase-negative staphylococci (CNS); coliforms; and fungi. Test-day milk data and clinical records were collected from June 2011 until February 2014. Mixed models with an autoregressive correlation structure were fitted to quantify the effects of CM and several other control variables (herd, calving season, parity, week of lactation, and other diseases). Primipara (first lactation) and multipara (second and later lactations) were analysed separately. All pathogens, particularly S. aureus and fungi, were associated with significant milk losses in multipara. In this study, S. aureus and CNS infections were not associated with significant milk loss in primipara. All pathogens, in particular S. aureus and fungi, significantly increased SCC in both parity groups. All pathogens, especially CNS (in primipara) and S. aureus (in multipara), decreased lactose content. All pathogen groups except for fungi were associated with significant changes in fat, protein and MUN. Some pathogens such as Streptococcus spp. and coliforms seemed to be associated with long-term fat, protein and MUN changes. These findings provide estimates that could be used to calculate precise costs of CM, and also provide better indicators of pathogen-specific mastitis.

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