Mastitis Management Research Articles

Exploiting machine learning methods with monthly routine milk recording data and climatic information to predict subclinical mastitis in Italian Mediterranean buffaloes

Mastitis has detrimental effects on the world's dairy industry, reducing animal health, milk production and quality, as well as income for farmers. In addition, consumers' growing interest in food safety and rational usage of antibiotics highlights the need to develop novel strategies to improve mastitis detection, prevention, and management. In the present study we applied machine learning (ML) analyses to predict presence or absence of subclinical mastitis in Italian Mediterranean buffaloes, exploiting information collected the previous month during routine milk recording procedures, as well as climatic data. The data set included 3,891 records of 1,038 buffaloes from 6 herds located in Basilicata Region (South Italy). Prediction models were developed using 4 different ML algorithms (Generalized Linear Model, Support Vector Machines, Random Forest, and Neural Network) and 2 data set splitting approaches for the creation of the training and test sets (by record or by animal ID number, always with 80% of the data used for model training and the remaining 20% for model testing). Support Vector Machine was the best method to predict high or low somatic cell count at the subsequent test-day record in the validation set, and therefore it was used to estimate the contribution of each feature to the best model. Independently from the data set splitting approach, the most important features were somatic cell score, differential somatic cell count, electrical conductivity, and milk production. Among climatic data, the most informative were temperature and relative humidity. When the data were split by animal ID, an improvement in models' predictive performance on the test set was observed, suggesting this as the most appropriate data splitting approach in data sets with repeated measures to avoid data leakage. According to different metrics, Neural Network was the best method for making predictions on the test set. Our findings confirmed the promising role of ML methods to improve prevention and surveillance of subclinical mastitis, exploiting the large amount of data currently available to identify animals that would possibly have high somatic cell count the subsequent month.

Association of Mastitis and Farm Management with Contamination of Antibiotics in Bulk Tank Milk in Southwest, China

Bovine mastitis could reduce the milk production and the quality of the bulk tank milk (BTM). Antibiotic treatments through intramammary or parenteral methods are being widely used in dairy farms. A cross-sectional study to investigate for general farm management and pre-test the questionnaire was performed in Southwestern Yunnan province, China. A total of 134 dairy farms were included. Milking cows of each farm were determined for the presence of clinical (CM) and sub-clinical (SCM) mastitis using the California Mastitis Test (CMT). Rates of CM and SCM in studied farms ranged from 2-11%, and 24-69%, respectively. The incidence of antibiotic residues in BTM of all farms was very high (32%, 44/134). All antibiotic contaminated samples were from smallholder dairy farms. Factors significantly associated with the presence of antibiotic contamination included farm region, antibiotics usage, persons performing mastitis treatment, and rates of CM. Rates of CM were significantly associated with the farm region, cleanliness of udders before milking, and the number of milking cows. Our results emphasize that the risk factors of dairy farm management should be paid attention, which can reduce mastitis prevalence and antibiotic contamination in BTM in Southwestern China.

PSXIV-9 Identification of Differential Methylation Regions as Candidate Discriminant Markers of Bovine Subclinical Mastitis Caused by Staphylococcus Aureus

Abstract Staphylococcus aureus (S. aureus) is one of the most prevalent pathogens of bovine subclinical mastitis and a challenging pathogen in dairy production. DNA methylation involvement in regulating mammary gland inflammatory defense has been documented. This study adopted whole genome bisulfite sequencing and RNA-sequencing technologies to profile the genome-wide DNA methylation and transcriptome landscapes, respectively, of milk somatic cells (MSCs) from 15 cows with S. aureus-induced subclinical mastitis (SACs) and 13 healthy cows (HCs). Bioinformatics processing of data with standard tools indicated that the global DNA methylation patterns of MSCs demonstrated inverse correlations between gene expression and DNA methylation levels at promoter, first exon and first intron regions, suggesting potential regulatory roles of DNA methylation in transcriptional activities. Totally, 26,289 differential methylation regions (DMRs) were identified between SACs and HCs (1,000 bp window, 1,000 bp step, q-value < 0.05, >20% methylation difference and ≥3 differentially methylated cytosines). A total of 887, 334 and 3,414 DMRs were overlapped with promoter, first exon, and first intron regions, respectively, including 363 DMRs harboring transcription start sites. Among them, the methylation levels of 956 DMRs were strongly correlated with the expression levels of their overlapped genes (|Spearman’s correlation coefficient| >0.5, adjusted-p-value< 0.05). Functional annotation of the overlapped genes indicated significant (adjusted-p-value < 0.05) enrichment in 18 GO terms and 1 KEGG pathway related to cellular activities, notably in cell migration, epithelial cell differentiation and tight junction, among others (Figure 1). These results suggest the involvement of DNA methylation in mammary gland defense against S. aureus-invasion. Applying DIABLO method to integrate correlated DMRs and genes, a total of 20 DMR and 10 gene candidate markers were found to discriminate SACs from HCs. The identified candidate markers could serve as reference for enhancing breeding for mastitis resistance and for developing new mastitis management strategies.

Construction of the waaF Subunit and DNA Vaccine Against Escherichia coli in Cow Mastitis and Preliminary Study on Their Immunogenicity.

Escherichia coli (E. coli) is one of the major pathogenic bacteria in bovine mastitis, which usually triggers systemic symptoms by releasing lipopolysaccharide (LPS). waaF is the core in LPS pathogenicity. In this study, a new waaF vaccine candidate was identified, constructed with the pcDNA3.1 (+)HisB-waaF plasmid to create to a DNA vaccine (pcwaaF), and transfected into MCF-7 cells to produce recombinant waaF subunit vaccine (rwaaF). After that, the safety of the two vaccine candidates was evaluated in mouse model. Immunogenicity and mortality of challenged mice were compared in 20 and 40 μg per dose, respectively. The results showed that rwaaF and pcwaaF were successfully constructed and the complete blood count and serum biochemical indicated that both of the vaccine candidates were safe (p > 0.05). In addition, histopathological staining showed no obvious pathological changes. The immune response induced by rwaaF was significantly higher than that of pcwaaF (p < 0.01), indicated by levels of serum concentration of IgG IL-2, IL-4, and IFN-γ, and feces concentration of sIgA. Survival rates of mice in rwaaF groups (both 80%) were also higher than in the pcwaaF groups (40 and 50%, respectively). Comparing the safety, immunogenicity, and E. coli challenge of two vaccine candidates, rwaaF had the better effect and 20 μg rwaaF was more economical. In conclusion, this study demonstrates the utility of a new E. coli vaccine and provides a rationale for further investigation of bovine mastitis therapy and management.

MAMMA (Mastitis And Mammary Abscess Management Audit): Phase 2 outcomes

Introduction: Due to subspecialisation, the management of mastitis and breast abscesses is thought to vary in the United Kingdom (UK) and Ireland. The aim of the Mastitis and Mammary abscess Management Audit (MAMMA) was to describe the current management these conditions in UK and Ireland.

Formation of Blood Neutrophil Extracellular Traps Increases the Mastitis Risk of Dairy Cows During the Transition Period.

The current study was conducted to analyze the functions of blood neutrophils in transition cows and their association with postpartum mastitis risk as indicated by somatic cell counts (SCCs) in milk. Seventy-six healthy Holstein dairy cows were monitored from Week 4 prepartum to Week 4 postpartum. Five dairy cows with low SCCs (38 ± 6.0 × 103/mL) and five with high SCCs (3,753 ± 570.0 × 103/mL) were selected based on milk SCCs during the first three weeks of lactation. At Week 1 pre- and postpartum, serum samples were obtained from each cow to measure neutrophil extracellular trap (NET)-related variables, and blood neutrophils were collected for transcriptome analysis by RNA sequencing. The serum concentration of NETs was significantly higher (P < 0.05) in cows with high SCCs than in cows with low SCCs (36.5 ± 2.92 vs. 18.4 ± 1.73 ng/mL). The transcriptomic analysis revealed that the transcriptome differences in neutrophils between high- and low-SCC cows were mainly in cell cycle-related pathways (42.6%), including the cell cycle, DNA damage, and chromosomal conformation, at Week 1 prepartum. The hub genes of these pathways were mainly involved in both the cell cycle and NETosis. These results indicated that the formation of NETs in the blood of transition dairy cows was different between cows with low and high SCCs, which may be used as a potential indicator for the prognosis of postpartum mastitis risk and management strategies of perinatal dairy cows.

Genome-Wide DNA Methylation and Its Effect on Gene Expression During Subclinical Mastitis in Water Buffalo.

Subclinical mastitis (SCM) in buffalo is one of the most challenging paradoxes for the dairy sector with very significant milk production losses and poses an imminent danger to milch animal’s milk-producing ability. We present here the genome-wide methylation specific to SCM in water buffalo and its consequential effect on the gene expression landscape for the first time. Whole-genome DNA methylation profiles from peripheral blood lymphocytes and gene expression profiles from milk somatic cells of healthy and SCM cases were catalogued from the MeDIP-Seq and RNA-Seq data. The average methylation in healthy buffaloes was found to be higher than that in the SCM-infected buffaloes. DNA methylation was abundant in the intergenic region followed by the intronic region in both healthy control and SCM groups. A total of 3,950 differentially methylated regions (DMRs) were identified and annotated to 370 differentially methylated genes (DMGs), most of which were enriched in the promoter region. Several important pathways were activated due to hypomethylation and belonged to the Staphylococcus aureus infection, Th17 cell differentiation, and antigen processing and presentation pathways along with others of defense responses. DNA methylome was compared with transcriptome to understand the regulatory role of DNA methylation on gene expression specific to SCM in buffaloes. A total of 4,778 significant differentially expressed genes (DEGs) were extracted in response to SCM, out of which 67 DMGs were also found to be differentially expressed, suggesting that during SCM, DNA methylation could be one of the epigenetic regulatory mechanisms of gene expression. Genes like CSF2RB, LOC102408349, C3 and PZP like, and CPAMD8 were found to be downregulated in our study, which are known to be involved in the immune response to SCM. Association of DNA methylation with transposable elements, miRNAs, and lncRNAs was also studied. The present study reports a buffalo SCM web resource (BSCM2TDb) available at http://webtom.cabgrid.res.in/BSCM2TDb that catalogues all the mastitis-related information of the analyses results of this study in a single place. This will be of immense use to buffalo researchers to understand the host–pathogen interaction involving SCM, which is required in endeavors of mastitis control and management.

Bacteriological outcomes following random allocation to quarter-level selection based on California Mastitis Test score or cow-level allocation based on somatic cell count for dry cow therapy

Intramammary infusion of antimicrobials at the end of lactation (dry cow therapy) has been a cornerstone of mastitis management for many years. However, as only a proportion of cows are infected at this time, treating only those cows likely to be infected is an important strategy to reduce antimicrobial usage and minimize risk of emergence of antimicrobial resistance. Such an approach requires the ability to discriminate between cows and quarters likely to be infected and uninfected. This study compared assignment of cows or quarters to antimicrobial treatment at the end of lactation based on cow composite somatic cell count (SCC; i.e., all quarters of cows with a maximum SCC across lactation >200,000 cells/mL received an antimicrobial; n = 891 cows, SCC-group) or assignment to quarter-level treatment based on a quarter level California Mastitis Test (CMT) score ≥ trace (n = 884 cows; CMT-group) performed immediately before drying off. All quarters of all cows also received an infusion of a bismuth-based internal teat sealant. Milk samples were collected for microbiology following the last milking, and again within 4 d of calving. Clinical mastitis records from dry off to 30 d into the subsequent lactation were collected. Multilevel, multivariable models were used to assess the effect of assignment to antimicrobial treatment. At drying off, a total of 575 (8.8%) and 147 (2.3%) of the 6,528 quarters had a minor, and a major intramammary infection (IMI), respectively. At drying off, 2089/3270 (63.9%) and 883/3311 (26.7%) of quarters were treated with dry cow therapy in the CMT and SCC-groups, respectively. Apparent bacteriological cure proportion for any IMI was higher in quarters assigned to the CMT than the SCC-group (349/368 (0.95, 95% CI 0.92-0.97) versus 313/346 (0.90, 95% CI 0.87-0.93)). New IMI proportion was lower among quarters assigned to the CMT than SCC-group [101/3,212 (0.032, 95% CI 0.025-0.038) versus 142/3,232 (0.044, 95% CI 0.036-0.051)]. The prevalence of any IMI postcalving was lower in quarters assigned to the CMT than SCC-group [119/3,243 (0.037, 95% CI: 0.030-0.044) versus 173/3,265 (0.054, 95% CI: 0.045-0.062)]. There was no difference in incidence of clinical mastitis between treatment groups. The total mass of antimicrobials used was 63% higher in the CMT-group than in the SCC-group (3.47 versus 2.12 mg/kg of liveweight). Selection of quarters for antimicrobial treatment at the end of lactation based on CMT resulted in greater proportion undergoing bacteriological cure, reduced risk of any new IMI and reduced post calving prevalence of any IMI compared with selection of cows based on SCC. However, CMT-based selection resulted in higher antimicrobial use compared with SCC-based selection, and further research is required to analyze the cost benefit and impact on risk of antimicrobial resistance of these 2 strategies.

Uso de antimicrobianos en vacas secas para controlar la mastitis en el Norte de Argelia

The control of mastitis is a crucial step in the preparation of the next lactation in dairy cows. In order to assess the practices and attitudes surrounding the use of antimicrobials at dry-off, a survey was conducted among veterinary practitioners in fifteen provinces of Northern Algeria. The results revealed that 45.95% of the farms followed by the respondents were rather small in size comprising about ten cows per farm and that a large majority of the farmers practised gradual drying off (72.97%) without adjusting the feed ration (70.27%) to this stage. Antibiotic dry cow therapy (DCT) was a common practice and selectively performed in 86.49% of cases regardless of udder health status. Cefalexin was the most infused intra-mammary (IMM) antibiotic (40.54%), while tylosin was the one favoured for parenteral administration (48.15%). Analysis of factors influencing the antibiotic DCT efficacy showed that a frequent (13.51%) occurrence of new intramammary infections (IMIs) was related to farmers’ attitudes (self-medication) and the policy of blanket DCT. Although the use of a teat sealant was uncommon (71.43%) in the farming traditions, the substitution of antibiotics seems to be a plausible prospect, since the majority of participants (89.19%) agreed with the implementation of aromatherapy concept at dry-off, mainly as a complement to antibiotics. This survey gives an overview of risk practices regarding mastitis management in northern Algeria. Hence, further zootechnical, veterinary and organizational efforts need to be made to promote animal production and welfare as well as public health through improved udder health.

Prevalence, Antimicrobial Susceptibility, and Molecular Characterization of Escherichia coli Isolated From Raw Milk in Dairy Herds in Northern China.

Escherichia coli is a common bacterium in the intestines of animals, and it is also the major important cause of toxic mastitis, which is an acute or peracute disease that causes a higher incidence of death and culling of cattle. The purpose of this study was to investigate E. coli strains isolated from the raw milk of dairy cattle in Northern China, and the antibacterial susceptibility of these strains and essential virulence genes. From May to September 2015, 195 raw milk samples were collected from 195 dairy farms located in Northern China. Among the samples, 67 (34.4%) samples were positive for E. coli. About 67 E. coli strains were isolated from these 67 samples. The prevalence of Shiga toxin-producing E. coli (STEC), enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), and enteroinvasive E. coli (EIEC) were 9, 6, 4.5, and 1.5%, respectively. Among the virulence genes detected, stx1 was the most prevalent (6/67, 9%) gene, followed by eae (3/67, 4.5%), and estB (2/67, 3%). Moreover, the strains exhibited different resistance levels to ampicillin (46.3%), amoxicillin-clavulanic acid (16.4%), trimethoprim-sulfamethoxazole (13.4%), tetracycline (13.4%), cefoxitin (11.9%), chloramphenicol (7.5%), kanamycin (7.5%), streptomycin (6.0%), tobramycin (4.5%), azithromycin (4.5%), and ciprofloxacin (1.5%). All of the E. coli isolates were susceptible to gentamicin. The prevalence of β-lactamase-encoding genes was 34.3% in 67 E. coli isolates and 45% in 40 β-lactam-resistance E. coli isolates. The overall prevalence of blaSHV, blaTEM, blaCMY, and blaCTX-M genes were 1.5, 20.9, 10.4, and 1.5%, respectively. Nine non-pathogenic E. coli isolates also carried β-lactamase resistance genes, which may transfer to other pathogenic E. coli and pose a threat to the farm’s mastitis management projects. Our results showed that most of E. coli were multidrug resistant and possessed multiple virulence genes, which may have a huge potential hazard with public health, and antibiotic resistance of E. coli was prevalent in dairy herds in Northern China, and ampicillin should be used cautiously for mastitis caused by E. coli in Northern China.

Potential Novel Biomarkers for Mastitis Diagnosis in Sheep.

Simple SummaryInflammation of the mammary gland (mastitis) is an important disease of dairy sheep. Mastitis management depends mainly on the diagnosis. Conventional diagnostic methods including somatic cell count, California Mastitis Test, and microbial culture have limitations. Therefore researchers are looking for new diagnostic biomarkers of mastitis including specific proteins produced by the liver in case of disease (acute phase proteins), unique genetic sequences (miRNAs), or antimicrobial peptides produced by immune cells during inflammation (cathelicidines).This review aims to characterize promising novel markers of ovine mastitis. Mastitis is considered as one of the primary factors for premature culling in dairy sheep and has noticeable financial, productional, and animal welfare-related implications. Furthermore, clinical, and subclinical mammary infections negatively affect milk yield and alter the milk composition, thereby leading to lowered quality of dairy products. It is, therefore, crucial to control and prevent mastitis through proper diagnosis, treatment or culling, and appropriate udder health management particularly at the end of the lactation period. The clinical form of mastitis is characterized by abnormalities in milk and mammary gland tissue alteration or systemic symptoms consequently causing minor diagnostic difficulties. However, to identify ewes with subclinical mastitis, laboratory diagnostics is crucial. Mastitis control is primarily dependent on determining somatic cell count (SCC) and the California Mastitis Test (CMT), which aim to detect the quantity of cells in the milk sample. The other useful diagnostic tool is microbial culture, which complements SCC and CMT. However, all mentioned diagnostic methods have their limitations and therefore novel biomarkers of ovine subclinical mastitis are highly desired. These sensitive indicators include acute-phase proteins, miRNA, and cathelicidins measurements, which could be determined in ovine serum and/or milk and in the future may become useful in early mastitis diagnostics as well as a preventive tool. This may contribute to increased detection of ovine mammary gland inflammation in sheep, especially in subclinical form, and consequently improves milk quality and quantity.

New standards in stochastic simulations of dairy cow disease modelling: Bio-economic dynamic optimization for rational health management decision-making

Bioeconomic models applied to animal health issues are now commonly observed in literature. This section of literature is very heterogeneous and the underlying methods are very diverse, from very simple methods (partial budgeting) to very complex ones. The objective of the present study is to build a new dynamic stochastic optimisation bioeconomic model applied to the dairy cow sector, that goes beyond some limitations usually found in methods used up to now. First, based on a critical literature review, we highlight four issues of bio-economic stochastic simulation models (BESSMs) applied to dairy cow diseases at the farm level. These models appear as partial (the farm system is not considered as a whole), unbalanced (between the economic and biological parts of the model), closed (to the farm environment) and only partially dynamic. To address these 4 main issues and improve the methodological standards in the microeconomics of dairy cow health management, we secondly develop a new bio-economic sequential optimization model (BESOM), called DairyHealthSim. DairyHealthSim aims to better consider both the context of decision-making and the farming system dynamics to define the best health management strategies in a given context. The biological part of the model simulates the complex dairy production cycle with a holistic approach. It is defined on a cow-week basis, and the weekly probabilities for all cow events, including production, reproduction and diseases, are simulated. The economic part of the model is a mean-variance optimization framework that dynamically represents the farmer's input allocation decision process under constraints. The biological and economic parts are closely integrated and the model is running with back and forth between the 2 parts of the bioeconomic model. Third, an application involving farmers' strategies related to biological risk management, labour willingness and market demand is proposed for dairy production and mastitis management. The results highlight the added value of the farming system-driven system coupled to economic optimization approach. DairyHealthSim identifies the optimal scenario for the entire ten-year simulation period or is based on yearly optimization (sequential modelling). The two different optimal solutions found show the usefulness of considering the dynamics and complexities of the actual field situation. The opportunity cost between the best and alternative solutions demonstrates that some solutions are economic equivalents. In conclusion, compared to approaches where the outcome is reduced to the monetary impact of diseases, DairyHealthSim is far more precise and appropriate for supporting decision-making.

Diagnostic properties of milk diversion and farmer-reported mastitis to indicate clinical mastitis status in dairy cows using Bayesian latent class analysis

The development of digital farming gives bovine mastitis research and management tools access to large datasets. However, the quality of registered data on clinical mastitis cases or treatments may be inadequate (e.g. due to missing records). In automatic milking systems, the decision to divert milk from the bulk milk tank during milking is registered (i.e. milk diversion indicator) for every milking and could potentially indicate a clinical mastitis case. This study accordingly estimated the diagnostic performance of a milk diversion indicator in relation to farmer-recorded clinical mastitis cases in the absence of a “gold standard”. Data on milk diversion and farmer-reported clinical mastitis from 3,443 lactations in 13 herds were analyzed. Each cow lactation was split into 30-DIM periods in which it was registered whether milk was diverted and whether clinical mastitis was reported. One 30-DIM period was randomly sampled for each lactation and this was the unit of analysis, this procedure was repeated 300 times, resulting in 300 datasets to create autocorrelation-robust results during analysis. We used Bayesian latent class analysis to assess the diagnostic properties of milk diversion and farmer-reported clinical status. We analyzed different episode lengths of milk diversion of 1 or more milk diversion days until 10 or more milk diversion days for two scenarios: farmers with poor-quality (51% sensitivity, 99% specificity) and high-quality (90% sensitivity, 99% specificity) mastitis registrations. The analysis was done for all 300 datasets. The results showed that for the scenario where the quality of clinical mastitis reporting was high, the sensitivity was similar for milk-diversion threshold durations of 1–4 days (0.843 to 0.793 versus 0.893). Specificity increased when the number of days of milk diversion increased and was ≥98% at a milk-diversion threshold durations of 8 or more consecutive milk diversion days. In the scenario where the quality of clinical mastitis reporting was low, the sensitivity of milk diversion and reported clinical mastitis cases was similar at milk-diversion threshold durations of 1–7 days (0.687 to 0.448 versus 0.503 to 0.504) while specificity exceeded the 98% at milk-diversion threshold durations of 7 or more consecutive milk diversion days. In both scenarios, a milk diversion threshold duration of 4–7 days achieved the most desirable combined sensitivity and specificity. This study concluded that milk diversion can be a valid alternative to farmer-reported clinical mastitis as it performs similarly in indicating actual clinical mastitis.

Assessing the perceptions and practices of peri-urban dairy farmers regarding bovine mastitis management in North-Western Nigeria

Peri-urban dairy farming is an emerging industry in sub-Saharan Africa that risks being undermined by diseases like bovine mastitis (BM) if farmers do not implement appropriate management programmes. However, little is currently known about farmer perceptions and practices towards BM due to challenges with accessing these herds for research. In this study, 49 intensive and 53 extensive peri-urban dairy farmers having ≥10 milking cows in Kaduna and Zaria metropolises, North-Western Nigeria were recruited through snowball sampling and on-farm interviews were conducted to collect information on herd demographics, milking procedures, and mastitis management. Descriptive statistics were provided for all study variables and statistical comparisons were made between intensive and extensive herds. The mean herd size was 33 milking cows (range: 11–62). A greater proportion of extensive herds contained only indigenous breeds of cattle (36/53; 68 %) compared with intensive herds (6/49; 12 %). Hand milking was the most common milking method across both herd types (93/102; 92 %). Intensive herds had better hand washing and udder cleaning practices, but there was no statistical difference between management systems with regards to floor, udder, and tail cleanliness. Only a small number of farms performed on-farm diagnosis of BM via strip cup test (4/102; 4%) or rapid mastitis test (3/102; 3%). Treatment of clinical mastitis was typically by intramuscular antibiotic injection (71/102; 70 %) or topically applied herbal preparations (14/102; 14 %). Dry cow intramammary therapy was only used by 6/46 intensive farms (13 %) and 1/53 extensive farms (2%). Most extensive herds (40/53; 76 %) reported milking cows with clinical mastitis after apparently healthy cows, however this practice was less common among intensive herds (5/49; 10 %). Extensive herds were less likely to request veterinary assistance for mastitis than intensive herds (17/53; 32 % versus 28/49; 57 %) and had higher perceived costs for treating BM cases. Intensive farmers reportedly received higher prices for milk than extensive farmers and perceived that BM was causing significantly more production losses in their herds. Only a small number of farmers (20/102; 20 %) kept mastitis treatment records for their herds. Overall, the study findings indicate that peri-urban dairy farmers may be lacking in awareness of BM impacts and access to basic resources to implement good practices such as hand washing between milking cows and antibiotic intramammary infusions.

Novel ways to use sensor data to improve mastitis management

Current sensor systems are used to detect cows with clinical mastitis. Although, the systems perform well enough to not negatively affect the adoption of automatic milking systems, the performance is far from perfect. An important advantage of sensor systems is the availability of multiple measurements per day. By clearly defining the need for detection of subclinical mastitis (SCM) and clinical mastitis (CM) from the farmers' management perspective, detection and management of SCM and CM may be improved. Sensor systems may also be used for other aspects of mastitis management. In this paper we have defined 4 mastitis situations that could be managed with the support of sensor systems. Because of differences in the associated management and the epidemiology of these specific mastitis situations, the required demands for performance of the sensor systems do differ. The 4 defined mastitis situations with the requirements of performance are the following: (1) Cows with severe CM needing immediate attention. Sensor systems should have a very high sensitivity (>95% and preferably close to 100%) and specificity (>99%) within a narrow time window (maximum 12 h) to ensure that close to all cows with true cases of severe CM are detected quickly. Although never studied, it is expected that because of the effects of severe CM, such a high detection performance is feasible. (2) Cows with mastitis that do not need immediate attention. Although these cows have a risk of progressing into severe CM or chronic mastitis, they should get the chance to cure spontaneously under close monitoring. Sensor alerts should have a reasonable sensitivity (>80%) and a high specificity (>99.5%). The time window may be around 7 d. (3) Cows needing attention at drying off. For selective dry cow treatment, the absence or presence of an intramammary infection at dry-off needs to be known. To avoid both false-positive and false-negative alerts, sensitivity and specificity can be equally high (>95%). (4) Herd-level udder health. By combining sensor readings from all cows in the herd, novel herd-level key performance indicators can be developed to monitor udder health status and development over time and raise alerts at significant deviances from predefined thresholds; sensitivity should be reasonably high, >80%, and because of the costs for further analysis of false-positive alerts, the specificity should be >99%. The development and validation of sensor-based algorithms specifically for these 4 mastitis situations will encourage situation-specific farmer interventions and operational udder health management.

Antimicrobial Resistance Profiles and Genes of Staphylococci Isolated from Mastitic Cow's Milk in Kenya.

Increasing numbers of potentially zoonotic multidrug-resistant (MDR) staphylococci strains, associated with mastitis in dairy cows, are being reported globally and threaten disease management in both animal and human health. However, the prevalence and antimicrobial resistance profiles of these strains, including methicillin-resistant staphylococci (MRS), in Kenya is not well known. This study investigated the drug resistance profiles and genes carried by 183 staphylococci isolates from 142 dairy cows representing 93 farms recovered from mastitis milk of dairy cows in two selected counties in Kenya. Staphylococci isolates were characterized by phenotypic characteristics, polymerase chain reaction (PCR) amplification, partial sequencing and susceptibility testing for 10 antimicrobial drugs. Detection of seven resistance genes to the various antimicrobial drugs was conducted using PCR. Overall, phenotypic resistance among the staphylococci ranged between 66.1% for ampicillin and 3.5% for fluoroquinolones. Twenty-five percent (25%) of S. aureus and 10.8% of the coagulase-negative staphylococci (CoNS) isolates, were methicillin-resistant staphylococci phenotypically (defined as resistance to cefoxitin disk diffusion). The most common genes found in S. aureus and CoNS were blaZ and strB at 44.3% and 26%, and 78% and 50%, respectively. MDR was observed in 29.67% and 16.3% of S. aureus and CoNS, respectively. These findings pose a threat to bovine mastitis treatment and management as well as human health.

04. MAMMA (Mastitis and Mammary abscess Management Audit): Phase 1 interim results

Introduction: Mastitis is a common benign breast condition. The aim of Phase 1 MAMMA study is to understand the current care pathway in the management of mastitis and breast abscess in the UK and Ireland.

O81: MAMMA: MASTITIS AND MAMMARY ABSCESS MANAGEMENT AUDIT

Abstract Presenting Author Email: alona.courtney@imperial.ac.uk Research question Is there significant variation in the management of mastitis and breast abscesses between different hospitals in the UK and Ireland? Background and Aim Lactational mastitis affects a third of breastfeeding women, 11% of whom develop breast abscesses. Non-lactational mastitis affects 5-9% of women. Management of mastitis includes alleviation of milk stasis and antibiotics. Ultrasound-guided needle aspiration is the recommended method of treatment for breast abscesses. Despite guideline recommendations, there is evidence suggesting significant variation in practice, particularly concerning antibiotic prescribing, rates of incision and drainage and length of inpatient treatment. Considering that the majority of breast surgeons are no longer participating in the on-call roster and the acute presentation of primary breast infections, we hypothesise that such variation in practice indeed exists across the UK and Ireland, where patients are treated by non-breast specialist general surgeons. The aim of the MAMMA study is to describe the current practice in the management of mastitis and breast abscesses in the UK and Ireland and to provide recommendations for best practice. Design Patients: Inclusion criteria: all female patients over the age of 16 with symptoms of mastitis or breast abscess. Exclusion criteria: 1) male patients, 2) underlying breast cancer, 3) breast surgery within 90 days of presentation, 4) breast implant in situ on the ipsilateral side. Intervention / Comparator (or main explanatory variable in an observational study): The following guidelines will be used as audit standards: 1) WHO Mastitis Guidelines 2000, 2) GAIN Guidelines on the Treatment, Management &amp; Prevention of Mastitis 2008, 3) ABM Clinical Protocol #4: Mastitis 2014, 4) NICE Clinical Knowledge Summaries: Mastitis and Breast Abscess MAMMA: Mastitis And Mammary abscess Management Audit Outcomes: Phase 1 will increase our understanding of the patient treatment pathways and ease of access to specialist breast services for patients with mastitis and breast abscesses. Phase 2 will collect prospective, real-time data on the management of mastitis and breast abscesses nationwide. Specifically, MAMMA will enable us to gather precise evidence on antibiotic prescribing, rate of operative versus radiological management, waiting time to ultrasound scan, rate of inpatient versus outpatient treatment, length of hospital stay and the rate of follow-up by breast surgeons. This highquality data will be instrumental in updating guidelines and help to standardise the management of mastitis and breast abscess across the UK and Ireland. Study design The study will be carried out in 3 phases with the support of a national trainee collaborative: 1) national practice survey, 2) prospective audit, 3) prospective re-audit. All acute hospitals that manage patients with mastitis and breast abscess will be invited to participate. All participating centres will be required to register this audit as per local protocol. All study data will be collected and managed using REDCap electronic data capture tool. Team and Infrastructure MAMMA National trainee collaborative will be established with the assistance of the Mammary Fold Academic and Research Committee and other regional research collaboratives. It will be the driving force behind this project. The trainee collaborative will be overseen by the MAMMA Steering Committee, convened from key stake-holders from a variety of medical and surgical specialties, allied health care professionals and patient representatives, who are directly involved in the management of patients with breast infections. MAMMA Study Management Group (SMG) will be responsible for audit management, data analysis, dissemination of results and drafting of publication. Regional trainee leads will represent each HEE region in the UK and Ireland and will be responsible for recruitment and coordination of local collaboratives; they will be directly accountable to the SMG. Local trainee collaboratives will consist of a local lead, maximum of two collaborators and one data validator. Further information is available on www.mammastudy.com.

In-vitro potential of crude extracts of selected garden herbs for mastitis management in Zambia

Introduction: The advent of bovine mastitis associated antimicrobial resistance has necessitated development of alternative herbal remedies. In this study, we tested, in-vitro, the antimicrobial efficacy of three crude extracts: (1) aqueous, (2) ethanol and (3) ethyl acetate extracts of Zambian cultivated Aloe barbadensis Miller (Aloe vera) and Curcuma longa (Turmeric) and also made comparisons to synthetic anti-mastitis formulations. Methods: The active compounds of these herbs were obtained as crude extracts using water, ethanol and ethyl acetate as solvents. The test microbes comprised of ten standard controls including Escherichia coli and Pseudomonas aeruginosa and 84 field isolates (all gram positive bacteria) from clinical and subclinical mastitis milk samples from selected districts of the Southern Province of Zambia belonging to the genera Staphylococcus, Streptococcus, Bacillus and Lactobacillus. The agar dilution method was used to determine the antimicrobial activity by observing the sensitivity which was graded as sensitive, intermediate or resistant. Commercial synthetic anti-mastitis preparations served as positive controls and their sensitivity was compared to that of the herbal preparations. The Minimum Inhibitory Concentrations (MIC) of the herbal formulation was also determined using two-fold serial dilutions. Results: The agar dilution test results of the field isolates indicated 18.8% resistance, 25.3% intermediate and 56% sensitivity for the herbal extracts, while the synthetic anti-mastitis preparation averaged 16.8% resistance, 4.75% intermediate and 78.5% sensitivity. The gram negative controls tested were generally resistant. On average, the agar dilution trials revealed; 41.8% resistance, 13% intermediate and 45.3% sensitivity for the herbal formulation while the synthetic antimicrobials produced 23.5% resistance, 5.2% intermediate and 71.3% sensitivity. Mean MIC was 11.5mg/ml at the 5% serial dilution for the herbal extract compared to the Cephalexin (semi-synthetic antimicrobial) MIC for S. aureus at 0.5mg/L or 0.0005mg/ml. Conclusion: The herbs Aloe vera and Curcuma longa from Zambia showed antimicrobial efficacy on bovine mastitis causing microbes and may be used as a cheaper alternative to synthetic anti-mastitis preparations and as an aid to fight antimicrobial resistance to the benefit of the most affected and resource limited small-scale dairy farmers.

Short communication: Comparative performance of 3 on-farm culture systems for detection of mastitis pathogens interpreted by trained and untrained observers

On-farm culture (OFC) systems facilitate pathogen-based mastitis management and can facilitate antimicrobial stewardship on dairy farms. Interpretation of the results, however, may present a challenge for those with limited microbiology experience. Here, we compared results of 3 OFC systems interpreted by trained and untrained observers against results of a standard laboratory reference method (aerobic culture and mass spectrometry). Milk samples (280 quarter and 60 composite) were selected from submissions for routine diagnostic testing to Quality Milk Production Services (Cornell University, Ithaca, NY) between August 2017 and January 2018. Samples were cultured simultaneously using the standard laboratory reference method and 3 commercially available OFC systems that varied in detail of pathogen identification (provided in parentheses) as follows: (1) Minnesota Easy Culture System II Bi-plate (University of Minnesota Laboratory for Udder Health, St. Paul; gram-positive, gram-negative), (2) Minnesota Easy Culture System II Tri-plate (gram-positive, gram-negative, some genus level), and (3) FERA Diagnostics and Biologicals AccuMast plate (Ithaca, NY; genus level, some species level). After 18 to 24 h of incubation, OFC plates were interpreted by 1 trained observer (>10 yr of experience in milk microbiology) and 6 untrained observers with no previous milk microbiology training, using only the manufacturers' instructions for guidance. Strength of agreement (κ) between observer groups and the reference method was determined for the available outcomes of each system. Interpreted by the trained observer, agreement was moderate for identifying gram-positive organisms (Bi-plate, κ = 0.56) and substantial for Streptococcus spp. (Tri-plate, κ = 0.64, AccuMast κ = 0.61). Interpretation by untrained observers resulted in fair agreement (κ = 0.29-0.37) for these organisms. Moderate agreement (κ = 0.43-0.59) was found across all 3 OFC for the identification of gram-negative organisms (Bi-plate), non-aureus staphylococci (Tri-plate and AccuMast), Lactococcus spp., and Enterococcus spp. (AccuMast) when interpreted by the trained observer, and fair to moderate agreement was found (κ = 0.31-0.53) among untrained observers. Across all 3 OFC, agreement was almost perfect (κ = 0.80-0.89) for Staphylococcus aureus for the trained observer, and moderate to substantial (κ = 0.56-0.61) for untrained observers. We concluded that all 3 OFC appeared suitable to support pathogen-based mastitis management when operated by trained observers. Training beyond the instruction manual is a prerequisite to make OFC systems useful for pathogen-based mastitis management.