Subclinical Mastitis Cases Research Articles

A study of the effectiveness of a detergent-based California mastitis test (CMT), using Ethiopian and Nigerian domestic detergents, for the detection of high somatic cell counts in milk and their reliability compared to the commercial UK CMT.

Background: The California mastitis test (CMT) is a simple cow-side indicator of the somatic cell count (SCC) in milk, providing a useful tool in identifying cases of subclinical mastitis in cattle. Mastitis, and in particular subclinical mastitis, is a major concern in Ethiopia and Nigeria, yet detection is challenging due to cost and access to commercial CMT reagents. Methods: Commercially available domestic detergents from Ethiopia and Nigeria were compared (n = 3 for each country) with the UK commercial CMT reagent in their ability to detect high SCC (>400,000 cells/ml milk). Sensitivity and specificity of the CMT test were calculated for the different detergents and positive and negative predictive values were established. Results: The average sensitivities of the tests ranged from 28-75% for the Ethiopian detergents and 68-80% for the Nigerian detergents, compared to 76% for the UK domestic detergent. Test specificities were 84-98%, 93-97% and 96%, respectively. Conclusions: Overall, the detergents demonstrated higher specificity than sensitivity. Nigerian detergents performed better than the Ethiopian products, however, the study identified suitable domestic detergents from both Ethiopia and Nigeria, comparable to the UK commercial CMT reagent, and we recommend their use as alternative CMT reagents for livestock-keepers to aid in cost-effective diagnosis of mastitis.

Staphylococcus aureus coa gene sequence analysis can prevent misidentification of coagulase-negative strains and contribute to their control in dairy cow herds.

Accurate and precise differentiation of staphylococci isolated from milk is of importance for udder health management. In particular, the rapid and specific identification of Staphylococcus aureus plays an essential role in the prevention and treatment programs for bovine mastitis. Plasma gelatinization in coagulase assays is routinely used to discriminate S. aureus from other species by detecting the presence of extracellular free staphylocoagulase. However, rarely occurring coagulase-deficient S. aureus strains can be responsible for clinical and subclinical mastitis cases. By investigating S. aureus isolates from a single herd over a 10-year period we identified the persistence of a phenotypically coagulase-negative S. aureus strain and pinpointed the possible cause to a single base pair deletion in the coa gene sequence. Our results support the need to integrate primary biochemical tests with molecular/sequence analysis approaches for correctly identifying and discriminating atypical S. aureus in bovine herds, as the coagulase test alone may fail to detect persistent mastitis-causing strains.

Flagella are an important virulence factor in the subclinical persistence of Escherichia coli in bovine mammary gland.

We compared the virulence profile and REP-PCR genotypes of Escherichia coli strains isolated from subclinical and clinical mastitis cases and dairy farm environments in Minas Gerais State, Brazil, to determine virulence factors and genotypes potentially associated with subclinical persistence in the udder. The virulence profile was obtained by the search for three virulence genes: lpfA (long polar fimbriae), fliC (flagella), and escN (type III secretion system). Subclinical isolates exhibited mainly the fliC gene (33.33%) and fliC + escN genes (30.30%). Clinical isolates exhibited mainly fliC + escN genes (50%) and environmental isolates the lpfA + escN genes (58.04%). Strains isolated from subclinical mastitis showed 6.75 times more positivity to fliC than environmental isolates. Thirty-four genotypes were observed in the REP-PCR analysis, and clinical mastitis isolates indicated more genetic proximity to dairy farm environment isolates than subclinical mastitis isolates. In conclusion, the results suggested that flagella may be an important virulence factor for mammary persistent E. coli infection in cattle, however, none of the E. coli REP-PCR genotypes were associated with subclinical infection.

An Evaluation of Draminski Detector as an Early Detection Tool for Subclinical Mastitis in Dairy Cattle in Pondok Ranggon Farm

Subclinical mastitis is one of the main problems in the development of dairy farming in Indonesia. Several screening test tools have been developed to support of control program for this problem. This study aimed to assess the suitability of the Draminski detector as a screening tool for subclinical mastitis in dairy cows. Quaternary milk samples from 27 dairy cows during normal lactation in the Pondok Ranggon area, East Jakarta were collected to be evaluated for the possibility of coming from quarters suffering from subclinical mastitis. Each milk sample was tested with 3 types of tests, i.e. the Breed method (golden standard) which was based on the number of somatic cells, the device Milkchecker which was based on electrical conductivity, and the Draminski detector which was based on electrical resistance. The results showed that the Draminski detector had a poor level of compatibility with the Breed method as the golden standard (Kappa value 0,013) and the Milkchecker tool (Kappa value 0,036). This test method was also considered to have poor test performance in diagnosing cases of subclinical mastitis in dairy cattle with a sensitivity value of 3,5%, specificity 100%, positive predictive value 100%, negative predictive value 18,8%, estimated prevalence 2,9%, and the true prevalence was 81,7%. In conclusion, the Draminski detector cannot be used to replace the Breed method and Milkchchecker as a screening test tool in cases of subclinical mastitis in dairy farms in Indonesia which were generally reared in the dairy farms.

The first study on antimicrobial resistance of Staphylococcus aureus isolated from raw goat milk associated with subclinical mastitis in Siliragung Subdistrict, East Java, Indonesia.

Raw goat milk is a highly nutritious dairy product and a suitable medium for the growth of antimicrobial-resistant Staphylococcus aureus, the leading cause of subclinical mastitis. This study aimed to investigate the resistance status of S. aureus which isolated from goat milk associated with subclinical mastitis cases in Siliragung Subdistrict, Banyuwangi District, East Java, Indonesia. The S. aureus isolates were recovered from 258 raw goat milk samples from seven different dairy goat farms. Preliminary screening of subclinical mastitis using the California mastitis test, then samples with score +3 and +4 were taken for further isolation and identification, followed by a biochemical test to determine the S. aureus. Moreover, the bacteria susceptibility test against several antimicrobials was done using the disk diffusion method. Based on our findings, a total of 66 (25.58%) raw goat milk samples were tested positive for S. aureus, of which 36.36% were identified as multidrug-resistant. Moreover, S. aureus were also identified as resistant to penicillin (81.82%), ampicillin (65.15%), erythromycin (50.52%), and gentamicin (36.09%). The prevalence of S. aureus isolated from raw goat milk associated with subclinical mastitis in Siliragung Subdistrict, Banyuwangi District, Indonesia, was recorded at 25.58%. Moreover, 36.36% of S. aureus isolates were categorized as resistant to three or more classes of antibiotics. The biosafety and biosecurity procedures during the milking process should be strengthened in dairy goat farms to prevent the transmission of antimicrobial resistance among animals, humans, and environments.

Clinical field trial of parenteral amoxicillin for the treatment of clinical and subclinical mastitis in smallholder dairy farms in the upper region of Northern Thailand.

Mastitis, primarily caused by intramammary bacterial infection, is the most expensive disease in the global dairy industry due to its negative impact on milk composition and manufacturing properties. This study aimed to evaluate the efficacy of parenteral amoxicillin in the treatment of clinical and subclinical mastitis in smallholder dairy farms in Northern Thailand. A total of 51 cows with clinical and subclinical mastitis from dairy cooperatives in Lamphun and Chiang Mai provinces, Northern Thailand, were enrolled in this study. Conventional bacteriological procedures were applied to identify the causative bacteria in milk samples from these cows before and 7 days after treatment, and antibiotic susceptibility tests were conducted using the disk diffusion method for all bacteria isolated before treatment. All cows with mastitis were administered 15 mg/kg of amoxicillin (LONGAMOX®, Syva Laboratories SA, Spain) intramuscularly every other day for 3 days. Environmental streptococcal bacteria (Streptococcus uberis and Streptococcus spp.) were commonly isolated from infected quarters and were highly susceptible to amoxicillin (100%). The clinical efficacy of amoxicillin treatment for clinical mastitis cases was 80.43%, and the bacteriological efficacy was 47.82%, with opportunistic staphylococcal bacteria (coagulase-negative staphylococci) and contagious streptococcal bacteria (Streptococcus agalactiae) being the most sensitive microorganisms (100%). In subclinical mastitis cases, the bacteriological efficacy of parenteral amoxicillin was 70.45%, with environmental streptococcal bacteria (S. uberis) being the most (100%) sensitive microorganisms. Amoxicillin is highly efficacious and can be used to treat clinical and subclinical mastitis in dairy cows, particularly mastitis caused by environmental Streptococcus spp. These findings could be used to guide treatment regimens in veterinary practice in smallholder dairy farms in Thailand.

Удосконалення профілактичних протимаститних заходів на молочних фермах

Goal. To study the spread of mastitis in heifers in dairy farms in the Ternopil region to improve measures for the prevention and treatment of this disease. Methods. Diagnostics of subclinical mastitis in animals was carried out using clinical studies of the mammary gland (examination, palpation, test milking of the secretion with visual assessment), mastidine test, and bacteriological studies (isolation of the pathogenic agent). Results. In the 8th month of pregnancy, when the heifer’s mammary gland begins to develop, pathogenic microorganisms can penetrate it and cause the development of an inflammatory process — it was diagnosed in 17.6% of animals. In the 9th month of pregnancy, 2 weeks before labor, the number of subclinical mastitis in heifers was diagnosed 1.7 times (p≤0.001) more often than 4 weeks before labor. This means that every third to fourth firstborn has inflammatory processes in the mammary gland even before lactation begins. Bacteria of the genera Staphylococcus and Streptococcus were mainly isolated from the udder secretions of animals suffering from subclinical mastitis. Thus, 4 weeks before calving, S. agalactiae microorganisms were recorded in 44.4% of disease cases, and S. uberis — 2 times less often (p≤0.001). 2 weeks before labor, the number of cases of mastitis caused by S. agalactiae was 35.7%, and that one caused by S. dysgalactiae and S. uberis was 2.5 times (p≤0.001) and 1.7 times (p≤ 0.01) smaller. It was also established that pathogenic microorganisms S.uberis in heifers caused subclinical mastitis 2.0–2.1 times (p≤0.001) more often than in first-born heifers during the first month of lactation. The number of cases of subclinical mastitis caused by S. aureus microorganisms in heifers and firstborns in the 1st month of lactation ranged from 28.6 to 33.4%. Conclusions. Preventive anti-mastitis measures on dairy farms should primarily consist in the diagnostics of mastitis in heifers at the 8-9th month of pregnancy and its treatment before labor.

Silver and Copper Nanoparticles as the New Biocidal Agents Used in Pre- and Post-Milking Disinfectants with the Addition of Cosmetic Substrates in Dairy Cows.

Mastitis is one of the most common issues for milk producers around the world. Antibiotic therapy is often ineffective, and therefore, scientists must find a new solution. The aim of this paper is to estimate the influence of common and well-known cosmetic substrates and mixtures of nanoparticles (NPs) and cosmetic substrates on the viability of frequently occurring mastitis pathogens, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The obtained results suggest that only collagen + elastin and glycerine influenced and increased bacteria viability. In case of the rest of the cosmetic substrates, the viability of E. coli and S. aureus was decreased, and the results were statistically significant (p ≤ 0.01). Prepared pre-dipping and dipping mixtures decrease (p ≤ 0.01) the viability of the mentioned pathogens. The obtained results of the in vitro analysis are very promising. In the next step, prepared mixtures should be tested in different herd conditions if they can be used in mastitis prevention or decrease the number of subclinical mastitis cases. Furthermore, these mixtures could become an interesting alternative for organic milk production where conventional preparations and antibiotics are forbidden. However, further analysis, especially on the influence of prepared mixtures on other bacteria species and, algae, fungi, are necessary.

Reservoirs of Corynebacterium spp. in the Environment of Dairy Cows.

Although Corynebacterium spp. can be regularly associated with subclinical and clinical mastitis cases in dairy cows, knowledge on their reservoirs in dairy farms is sparse. Therefore, samples were collected at 10 visits with 14 day intervals from bedding material (n = 50), drinking troughs (n = 20), different walking areas (n = 60), cow brushes (n = 8), fly traps (n = 4), the passage to pasture (n = 9) as well as milking liners (n = 80) and milker gloves (n = 20) in one dairy cow farm. Additionally, quarter foremilk samples from all lactating cows (approximately 200) were collected at each visit. All samples underwent microbiological examination and cultured isolates were identified using MALDI-TOF MS. Most Corynebacterium spp. that were cultivated from milk were also isolated from the housing environment and milking-related niches (C. amycolatum, C. confusum, C. stationis, C. variabile, C. xerosis) or from milking-related niches only (C. frankenforstense, C. pilosum, C. suicordis). C. bovis was not cultivated from any environmental niche, while being the dominant species in milk samples. This study demonstrates that many Corynebacterium spp. present in milk samples can also be isolated from the cows' environment. For C. bovis, the most relevant Corynebacterium species with regard to intramammary infections, it indicates that environmental reservoirs are of little relevance.

Determination of antibiotic resistance and biofilm formation in Klebsiella strains isolated from bovine mastitis cases

Mastitis is diseases of dairy cows with a high economic impact. Bovine mastitis is caused by a wide range of bacterial pathogens. As one of the major environmental pathogens Klebsiella ssp. was investigated in this study by some phenotypic characteristics like antibiotic resistance patterns and biofilm formation properties. A number of 483 cows by dairy farms around the Konya were examined by California Mastitis Test (CMT) producing 36 positive in terms of subclinical mastitis. A further 19 samples from clinical mastitic udders were also collected. Samples were inoculated onto Trypticase Soy Agar medium enriched with sheep blood and incubated aerobicaly for 24-48 hours at 37 °C. By morphological, biochemical and cultural charcateristics 14 isolates out of 37 coliform were identified as Klebsiella ssp. The double disc synergy method and Congo Red Agar test were used to perform antibiotic susceptibility and in vitro slime forming properties, respectively. Resistances to the antibiotics Ampicillin, Carbenicillin, Cephotaxime, Chloramphenicol, Erythromycin, Gentamicin, Neomycin, Oxytetracycline, Sulphamethoxazole/Trimpethoprim, Amoxicillin-Clavulanate and Imipenem were 78.5%, 78.5%, 35.7%, 42.8%, 100%, 7%, 7%, 50%, 14%, 21% and 7%, respectively. Three of the total isolets produced biofilm only. This appears to the first report on ESBL producing Klebsiella ssp from subclinical cases of bovine mastitis in Konya, Türkiye. Presently, two numbers of antimicrobial combinations to treat bovine cases are recommended by this work. In conclusion, because of costly challange nature of Klebsiella caused bovine mastitis implemantation of an effective mastitis control program should be used in local farms from Konya.

Antimicrobial Resistance and Virulence Genes of Enterococci Isolated from Water Buffalo's Subclinical Mastitis

This study aimed to investigate the antimicrobial resistance and virulence genes of enterococci isolated from water buffalo’s subclinical mastitis cases. The antimicrobial susceptibilities of the isolates were determined by the disc diffusion method. Identification at the species level of enterococci, virulence [aggregation substance (asa1), gelatinase (gelE), cytolysin (cylA), enterococcal surface protein (esp), and hyaluronidase (hyl)] and resistance genes [macrolide (ermA, ermB, mefA/E) and tetracycline (tetK, tetL, tetM, tetO, and tetS)] were investigated by polymerase chain reaction (PCR). Overall, Enterococcus spp. was recovered from 65 of 200 (32.5%) mastitic milk samples, comprising E. faecium (n=26), E. durans (n=22), E. faecalis (n=12), and E. hirae (n=5). Most isolates (56.9%) were susceptible to all tested antibiotics. The rest of the isolates showed various rate of resistance against rifampicin (23.1%), tetracycline (21.5%), quinupristin-dalfopristin (10.8%), ciprofloxacin (7.7%), erythromycin (6.2%), and chloramphenicol (3.1%). Out of 65 enterococci, only 16 (24.6%) were detected to have virulence genes, of which 12 were positive for gelE, seven were positive for esp, two were positive for asa1, and one was positive for hlyA. The gene cylA was not detected in any isolate tested. Resistance to tetracycline was mainly associated with tetM. Two erythromycin-resistant isolates were positive for ermB, and one was positive for mefA/E. This study was the first to report species distribution, antimicrobial susceptibility, and virulence traits of enterococci isolated from subclinical mastitis of water buffaloes in Çorum Province, Türkiye.

Staphylococcus aureus from Subclinical Cases of Mastitis in Dairy Cattle in Poland, What Are They Hiding? Antibiotic Resistance and Virulence Profile.

Bovine mastitis is a common disease worldwide, and staphylococci are one of the most important etiological factors of this disease. Staphylococcus aureus show adaptability to new conditions, by which monitoring their virulence and antibiotic resistance mechanisms is extremely important, as it can lead to the development of new therapies and prevention programs. In this study, we analyzed Staphylococcus aureus (n = 28) obtained from dairy cattle with subclinical mastitis in Poland. The sensitivity of the isolated strains to antibiotics were confirmed by the disc diffusion method. Additionally, minimum inhibitory concentration values were determined for vancomycin, cefoxitin and oxacillin. Genotyping was performed by two methods: PCR melting profile and MLVF-PCR (multiple-locus variable-number tandem-repeat fingerprinting). Furthermore, the presence of antibiotic resistance and virulence genes were checked using PCR reactions. The analyzed strains showed the greatest resistance to penicillin (57%), oxytetracycline (25%) and tetracycline (18%). Among the analyzed staphylococci, the presence of 9 of 15 selected virulence-related genes was confirmed, of which the icaD, clfB and sea genes were confirmed in all staphylococci. Biofilm was observed in the great majority of the analyzed bacteria (at least 70%). In the case of genotyping among the analyzed staphylococci (combined analysis of results from two methods), 14 patterns were distinguished, of which type 2 was the dominant one (n = 10). This study provides new data that highlights the importance of the dominance of biofilm over antibiotic resistance among the analyzed strains.

Genetic associations between mastitis, milk electrical conductivity, and milk flow rate in temperate dairy cows in tropics

Milk electrical conductivity and milk flow rate are potential indicators in selection targeting mastitis resistance. This study aimed to estimate the genetic parameters for clinical mastitis, average daily milk electrical conductivity (EC), milk flow rate (FR), and milk yield (MY) for the first lactation of imported Jersey and Jersey-Friesian dairy cows in Sri Lanka. Genetic parameters for mastitis traits, the prevalence of clinical mastitis in each cow, the duration of clinical mastitis treatment, and the number of episodes of mastitis were estimated using univariate sire models with permanent environmental effect of the cow added to models for prevalence of clinical mastitis in each day of milk over the whole lactation, or within the first 100-days of milk. The genetic parameters for the traits EC, FR, and MY over the whole lactation and for these traits defined for 30-day intervals were estimated using univariate animal models. For all mastitis traits, a zero heritability was estimated under both normal and logit scales. Heritabilities of EC and FR ranged from 0.02 to 0.11 and from 0.02 to 0.14, respectively. Genetic correlations between MY and EC and between MY and FR around peak milk yield were 0.25 ± 0.46 and 0.46 ± 0.29, respectively. Based on the heritability estimates for mastitis, dairy cows in this study cannot be directly selected for mastitis resistance, but indirect selection via EC and FR is feasible. Recording all cases of both sub-clinical and clinical mastitis in subsequent lactations is recommended to aid selection of dairy cows for mastitis resistance.

Diversity and emergence of multi-resistant Staphylococcus spp. isolated from subclinical mastitis in cows in of the state of Piauí, Brazil.

This research aimed to identify the diversity of bacterial species of the genus Staphylococcus spp. in subclinical mastitis in dairy herds in the state of Piauí, Northeastern Brazil, and to evaluate the phenotypic and genotypic resistance profile. Samples were obtained from a total of 17 dairy farms, amounting to 321 positive samples in the California Mastitis Test. Staphylococcus spp. were identified by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy. Subsequently, an antibiogram was performed, and a polymerase chain reaction was carried out to screen for resistance genes in the isolates. Among all the isolates, 59.45% (110/185) belonged to the Staphylococcus genus. Moreover, the following Staphylococcus spp. were identified Staphylococcus aureus, 68.1% (75/110); Staphylococcus chromogenes, 12.7% (14/110); Staphylococcus epidermidis, 5.4% (6/110); Staphylococcus sciuri, 4.5% (5/110); Staphylococcus warneri, 2.7% (3/110); Staphylococcus haemolyticus, 1.8% (2/110); Staphylococcus hominis, 1.8% (2/110); Staphylococcus arlettae, 0.9% (1/110); Staphylococcus capitis, 0.9% (1/110); and Staphylococcus gallinarum, 0.9% (1/110). The antibiogram showed a high frequency of resistance to penicillin and ampicillin, 70.0% (77/110) and 61.8% (68/110), respectively, and a low frequency of resistance to gentamicin and vancomycin, 10.9% (12/110) and 11.8% (13/110), respectively. In the genotypic tests for the different species of Staphylococcus spp., the occurrence of the blaZ gene was observed in 60.9% (67/110) of the isolates, followed by tetL and tetM, both with 20.0% (22/110) each, and the mecA and vanB genes were detected in 0.9% (1/110) of the samples. The identification of all Staphylococcus species isolated from subclinical mastitis cases and the phenotypic and genotypic resistance characterization in these isolates is of great importance for dairy farming in the state of Piauí, as well as for public health.

Forecasting chronic mastitis using automatic milking system sensor data and gradient-boosting classifiers

Although most of the losses due to mastitis per case in dairy production are estimated to be caused by clinical cases, subclinical cases, especially chronic, can also be problematic due to milk production losses and the risk of transmission of pathogens. Knowing which subclinical mastitis cases will become chronic at an early stage would be helpful in intervening in these cases. Automatic milking systems (AMS) can collect data on mastitis indicators such as conductivity, Somatic cell count (SCC), and blood in the milk for each milking. The aim of this study was to develop a sensor-based prediction model using SCC, conductivity, blood in the milk, parity, milk diversion, time interval between milkings, milk yield and DIM that forecasts the chronicity in subclinical mastitis cases after an initial increase in SCC. We used sensor data from 14 European and North American dairy farms (with herd sizes of lactating cows ranging from 55 to 638 cows and herd mean parities between 2.00 and 3.19) with an AMS and an online cell counter, measuring SCC. Typically, a threshold of 200,000 SCC/ml has been used to distinguish cows with subclinical mastitis from healthy cows. We used gradient-boosting trees and sensor data to forecast whether the SCC would decrease structurally below 200,000 SCC/ml in 50 days after the day at which the prediction was performed. Data from 30 and 15 days prior to the day where the forecast was made, was used. The model was trained on data from seven randomly selected dairy farms from the dataset and the data of the remaining seven dairy farms were used to estimate the predictive performance. These results were compared with two approaches that simulate how farmers would diagnose chronic mastitis with a simple prediction rule based on close-to-daily SCC (frequent sampling approach), and on less frequent monthly SCC (monthly sampling approach). We used accuracy, Matthew’s correlation coefficient (MCC), and Area under the Curve (AUC) as metrics to assess the forecasting performance of the chronic mastitis prediction model. On average, the forecast model, using 30 days of sensor data prior to the day of prediction, outperformed the approaches according to the accuracy (chronic mastitis prediction model: 0.888, frequent sampling approach: 0.848, and monthly sampling approach: 0.865), MCC (chronic mastitis prediction model: 0.712, frequent sampling approach: 0.630, and monthly sampling approach: 0.552), and AUC metrics (chronic mastitis prediction model: 0.964 and frequent sampling approach: 0.941) metrics. The results also indicate that shortening the input requirement from 30 days of prior sensor data to 15 days has a limited effect on the performance of the model. Overall, this study shows that it is possible with a high accuracy to predict the future chronic mastitis status using past sensor data and machine learning models.

"Cultural Isolation, Identification and Antibiotic Resistance of Streptococcus agalactiae from Bovine Sub-Clinical Mastitis Cases"

"Cultural Isolation, Identification and Antibiotic Resistance of Streptococcus agalactiae from Bovine Sub-Clinical Mastitis Cases"

Effect of selective dry cow treatment on udder health and antimicrobial usage on Dutch dairy farms

Since 2013, selective dry cow treatment (SDCT) has been the standard approach in the Netherlands where farmers select cows for the use of antimicrobials at drying-off. Shortly after its introduction, antimicrobial usage decreased significantly, and no significant association was found between the level of SDCT and clinical mastitis (CM). Obviously, at that time long-term associations could not be evaluated. This study aimed to provide insight into the methods and level of implementation of SDCT on Dutch dairy farms with a conventional milking system (CMS) or an automatic milking system (AMS) in 2016 and 2017, several years after the implementation of SDCT. Udder health and antimicrobial use were also assessed. For this study, 262 farmers recorded dry cow treatments as well as all CM cases in the period from May 1, 2016, until April 30, 2017. Additionally, somatic cell count (SCC) data on cow and herd level, treatment data on herd level and questionnaire results on udder health management were collected. Data were analyzed using descriptive statistics with differences between milking systems being evaluated using nonparametric univariable statistics. In the study period, SDCT was applied on almost all (98.8%) of the participating dairy farms. The main reason for applying antimicrobials at drying-off was either the SCC history during the complete previous lactation or the SCC at the last milk recording before drying-off. The median percentage of cows treated with antimicrobials was 48.5%. The average incidence rate of CM was 27.3 cases per 100 cows per year. From all CM cases that were registered per herd, on average 32.8% were scored as mild, 42.2% as moderate, and 25.0% as severe CM. The mean bulk tank SCC of the herds was 168,989 cells/mL. A cow was considered to have subclinical mastitis (SCM) if individual SCC was ≥150,000 cells/mL for primiparous and ≥250,000 cells/mL for multiparous cows. Passing these threshold values after 2 earlier low SCC values was considered a new case of SCM. The mean incidence rate of SCM in these herds was 62.5 cases per 100 cows per year. Bulk tank SCC and the incidence rate of SCM on farms with a CMS were statistically lower than on farms with an AMS, whereas the incidence rate of CM did not significantly differ between both groups of farms. The AMS farms had more cows per herd treated with antimicrobials at drying-off and a larger proportion of severe CM cases than did CMS farms. It is unknown whether the differences are due to the milking system or to other differences between both types of farms. This study showed the level of adoption of SDCT, udder health, and antimicrobial usage parameters several years after the ban on the preventive use of antimicrobials in animal husbandry. It found that udder health parameters did not differ from those found in Dutch studies before and around the time of implementing SDCT, whereas SDCT was widely applied on Dutch dairy farms during the study period. Therefore, it was concluded that Dutch dairy farmers were able to handle the changed policy of antimicrobial use at drying-off while maintaining indicators of a good udder health.

The Empowerment of Livestock Farmers in Subclinical Mastitis Test with GAMA Anti-Haptoglobin in “Sahabat Ternak” Etawah Crossbreed Goat Farm

Sahabat Ternak is one of the Etawah crossbreed (PE) goat farm groups in Sleman. This farm group focuses on goat milk production and processed goods. Problems that commonly arise in dairy goat farms are the cases of subclinical mastitis, which are quite high. This disease may cause a decrease in milk production and quality. The mastitis subclinical detection method which is often used by the farming community is the somatic cell count (SCC) and California mastitis test (CMT). However, both tests have low accuracy. Recently, a new method named GAMA Anti-Haptoglobin, which is more accurate and can be done easily has been established by livestock farmers. This community service aims to empower livestock farmers in applying GAMA Anti-Haptoglobin as a sensitive, rapid, and accurate subclinical mastitis detection kit in Sahabat Ternak goat farm. The method used in this activity consisted of discussion, socialization, and training for livestock farmers, as well as laboratory testing, evaluation of test findings, and treatment for PE goats. After the training, the livestock farmers were able to apply GAMA Anti-Haptoglobin mastitis detection method effectively. The implementation of this easy and accurate field mastitis detection method, as well as personnel with reliable skills, will support in the decrease of mastitis cases and increase milk production and quality, as well as community welfare.

Genetic characterization and comparative genomics of a multi drug resistant (MDR) Escherichia coli SCM-21 isolated from a subclinical case of bovine mastitis

Escherichia coli is one of the major pathogens causing mastitis that adversely affects the dairy industry worldwide. This study employed whole genome sequence (WGS) approach to characterize the repertoire of antibiotic resistance genes (resistome), virulence genes (virulome), phylogenetic relationship and genome wide comparison of a multi drug resistant (MDR) E. coli(SCM-21) isolated from a case of subclinical bovine mastitis in Bangalore, India. The genome of E. coli SCM- 21 was found to be of 4.29 Mb size with 50.6% GC content, comprising a resistome of 22 genes encoding beta-lactamases (blaTEM,blaAmpC), polymyxin resistance (arnA) and various efflux pumps (acr, ade, emr,rob, mac, mar, rob), attributing to the bacteria’s overall antibiotic resistance genetic profile. The virulome of E. coli SCM-21 consisted of genes encoding different traits [adhesion (ecp, fim, fde), biofilm formation (csg) and toxin production (ent, esp, fep, gsp)], necessary for manifestation of the infection. Phylogenetic relationship of E. coli SCM- 21 with other global E. coli strains (n = 4867) revealed its close genetic relatedness with E. coli strains originating from different hosts of varied geographical regions [human (Germany) bos taurus (USA, Belgium and Scotland) and chicken (China)]. Further, genome wide comparative analysis with E. coli (n = 6) from human and other animal origins showed synteny across the genomes. Overall findings of this study provided a comprehensive insight of the hidden genetic determinants/power of E. coli SCM-21 that might be responsible for manifestation of mastitis and failure of antibiotic treatment. Aforesaid strain forms a reservoir of antibiotic resistance genes (ARGs) and can integrate to one health micro biosphere.

Emulsion-Based Postbiotic Formulation Is Comparable to Viable Cells in Eliciting a Localized Immune Response in Dairy Cows With Chronic Mastitis.

Bovine mastitis is a disease with a multi-etiological nature, defined as an infection and inflammation of the udder. Mastitis represents a significant ongoing concern in the dairy industry, leading to substantial losses in profits and revenue for farmers worldwide. The predominant causes of bovine mastitis include the pathogens Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus uberis, and Escherichia coli. Antibiotic administration is currently the main treatment option for mastitis. However, there is a pressing need for alternative therapies to treat and prevent the disease, especially with the emergence of antibiotic-resistant, mastitis-causing pathogens, resulting in antibiotic treatment failure. One such example is live bio-therapeutics (also known as probiotics), such as Lactococcus lactis DPC3147. The efficacy of this live bio-therapeutic has been demonstrated in several previous trials by our group. The most recent of these trials showed that an emulsion-based formulation of this strain was as effective as a commercial antibiotic formulation in treating sub-clinical and clinical cases of bovine mastitis. Here, we report the results of a follow-up field trial, in which we sought to gain insight into the mechanism of action of such live bio-therapeutics, focussing on chronic mastitis cases. We treated 28 cows with chronic mastitis with two separate emulsion-based formulations containing either viable L. lactis DPC3147 cells (15 cows) or heat-killed L. lactis DPC3147 cells (13 cows). We then evaluated the efficacies of the two formulations (two treatment groups) in terms of stimulating a localized immune response (quantified by measuring IL-8 concentrations in milk collected from udders affected by mastitis) and efficacies in terms of cure rates (quantified by reductions in somatic cell counts and absence of pathogens). We demonstrate that the presence of heat-inactivated bacteria (a postbiotic) was as effective as the live bio-therapeutic in eliciting a localized immune response in cows with chronic mastitis. The response to heat-killed cells (postbiotic) reported herein could have beneficial implications for farmers with regard to prolonging the shelf life of such emulsion-based formulations containing heat-killed cells of L. lactis DPC3147 for curing cows with mastitis.