RESUMEN

This study describes the association of non-esterified fatty acids (NEFA) and calcium concentrations at calving with early lactation disease, reproductive performance and culling in 646 dairy cows from 13 commercial grazing dairy herds in Uruguay. During one year, health events were recorded from calving to 30 days in milk (DIM). The first author visited each farm every 20 days. During each visit, body condition score (BCS) was recorded (scale 1-5), defining BCS < 3 as suboptimal and BCS > 3 as optimal, and a blood sample was taken from cows between 0 and 4 DIM for metabolite determination. To evaluate the association between health events (i.e., retained placenta-metritis and clinical mastitis) and risk factors (parity, BCS, high NEFA (> 0.6 mmol/L) and subclinical hypocalcemia (SCH) (< 2.10 mM)) data were analysed using multivariable logistic regression models. To evaluate the association of health events and risk factors with reproductive performance and culling, data were analysed using Cox proportional hazard regression models. A risk factor and an outcome of interest were assumed to be associated at P < 0.05 and a tendency to be associated was defined at P < 0.10. Overall, 47 % (n = 303) of the cows showed elevated NEFA concentration and 77 % (n = 499) had SCH. In addition, 21.5 % (n = 139) of the cows recorded at least one clinical disease. Cumulative incidence was 17 % (n = 109) for clinical mastitis, 4.2 % (n = 27) for retained placenta (RP)-metritis and 1.4 % (n = 7) for lameness. Clinical mastitis was associated with parity, with lower odds in primiparous (PP) cows (OR = 0.42, P < 0.01). Cows in an optimal BCS also tended to have lower odds (OR = 0.66, P = 0.07). Moreover, high NEFA and SCH cows had higher odds of CM (OR = 4.5, P = 0.01 and OR = 1.75, P = 0.04, respectively). Retained placenta-metritis tended to be associated with high NEFA concentration (OR = 2.2, P = 0.06). Primiparous cows with suboptimal BCS showed an increased first insemination rate (HR = 2.34; P < 0.01). The risk of culling was lower in PP cows (HR = 0.19; P < 0.01) and in cows with optimal BCS and low NEFA concentration (HR = 0.38; P = 0.03). Our data show that metabolic challenge (defined as peripartum suboptimal BCS, high NEFA or SCH) is associated with increased odds of clinical mastitis and RP-metritis, decreased probability of insemination and increased hazard of culling. Under grazing conditions, we suggest that farm management to improve the metabolic adaptation to lactation represents an opportunity to enhance cow performance in terms of health, fertility and longevity.

Asunto(s)

Calcio , Enfermedades de los Bovinos , Ácidos Grasos no Esterificados , Lactancia , Animales , Bovinos/fisiología , Femenino , Ácidos Grasos no Esterificados/sangre , Lactancia/fisiología , Uruguay/epidemiología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/sangre , Calcio/sangre , Embarazo , Factores de Riesgo , Fertilidad/fisiología , Mastitis Bovina/epidemiología , Industria Lechera , Hipocalcemia/veterinaria , Hipocalcemia/epidemiología , Endometritis/veterinaria , Endometritis/epidemiología , Retención de la Placenta/veterinaria , Retención de la Placenta/epidemiología , Retención de la Placenta/sangre

RESUMEN

This study aimed to evaluate the relationship between prepartum subclinical hypomagnesemia (pre-SHMg) and the occurrence of dystocia, metritis, clinical mastitis, lameness, and subclinical hypomagnesemia postpartum (post-SHMg) in pasture-based dairy cows. Also, the difference in means of prepartum magnesium (Mg) concentration by postpartum health events was evaluated. A total of 890 dairy cows from 32 commercial farms located in southern Chile were enrolled. Cows were examined twice, once between 30 and 3 days before and once between 3 and 30 days after calving. Blood samples were collected on both assessments, and cows were considered as having SHMg if serum total Mg < 0.65 mmol/L. On the postpartum visit, cows were evaluated for metritis and lameness. Information about clinical mastitis and dystocia was collected from on-farm records. Data were analyzed using multivariable mixed linear models and multivariable mixed logistic regression models. The overall prevalence of pre-SHMg was 9.9%, and its presence was associated with the occurrence of post-SHMg (odd ratio [OR] = 5.7; P < 0.0001) and metritis (OR = 3.1; P = 0.04). However, we did not detect an association between pre-SHMg and dystocia, clinical mastitis, or lameness after calving. Prepartum serum Mg concentrations were lower in cows that developed post-SHMg than those that did not (LSM ± SE = 0.75 ± 0.02 mmol/L vs. 0.83 ± 0.02 mmol/L; P < 0.0001). In conclusion, pre-SHMg was associated with a higher risk of post-SHMg and metritis in grazing dairy cows but not other postpartum health events.

Asunto(s)

Enfermedades de los Bovinos , Magnesio , Periodo Posparto , Animales , Bovinos , Femenino , Chile/epidemiología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/sangre , Embarazo , Magnesio/sangre , Magnesio/análisis , Distocia/veterinaria , Distocia/epidemiología , Prevalencia , Endometritis/veterinaria , Endometritis/epidemiología , Endometritis/sangre , Deficiencia de Magnesio/veterinaria , Deficiencia de Magnesio/epidemiología , Deficiencia de Magnesio/sangre , Mastitis Bovina/epidemiología , Mastitis Bovina/sangre , Cojera Animal/epidemiología , Cojera Animal/etiología , Cojera Animal/sangre , Industria Lechera

RESUMEN

Mastitis, a multifactorial disease influenced by both cow and herd-level factors, results in significant losses throughout the dairy chain. We aimed to evaluate the relationship between milking frequency (MF), parity order (PO), days in milk (DIM), and milk yield (MY) on somatic cell count (SCC) and the odds of a cow having subclinical mastitis (SCM) in Brazilian Holstein and Jersey dairy cows. Our dataset consisted of 747,520 test-day records from 52,954 cows, including 49,089 Holstein cows and 3865 Jersey cows and 498 herds. The SCC was evaluated using a generalized linear mixed model, whereas SCM occurrence was evaluated using a logistic regression model. A case of SCM was defined when a cow had >200×103 cells/mL. Our results indicated that the SCC increases with higher PO and DIM and decreases in cows milked three times a day and those with higher MY in both breeds (>40 and >25 L/d for Holstein and Jersey, respectively). Increasing MF from two to three times a day reduced the chances of a Holstein and Jersey cow having SCM by 10 and 20 %, respectively. For Holstein and Jersey cows, those with ≥quadriparous had 3.9 times and 2.2 times higher chances, respectively, of having SCM compared to primiparous cows. Cows with >305 DIM had 2.0 times greater chances of having SCM for both, Holstein and Jersey cows, compared to cows with ≤105 DIM. Holstein cows yielding ≥40 L/d had a 75 % lower chance of having SCM compared to those yielding <20 L/d, while Jersey cows with ≥25 L/d had a 60 % lower chance compared to those yielding <15 L/d. In conclusion, higher PO and DIM pose risks, whereas a MF of three times a day and higher MY are protective factors against increases in SCC and SCM occurrence in Brazilian Holstein and Jersey cows.

Asunto(s)

Industria Lechera , Mastitis Bovina , Leche , Animales , Bovinos , Mastitis Bovina/epidemiología , Femenino , Brasil/epidemiología , Factores de Riesgo , Recuento de Células/veterinaria , Leche/citología , Lactancia , Paridad

RESUMEN

This study evaluated the economic impacts caused by mastitis in a small dairy farm with similar characteristics and production to most dairy farms in southern Brazil and investigated if climatic variations influenced mastitis occurrence in the region. A farm with, on average, 45 lactating Holstein cattle was monitored from November 2021 to October 2022, and data on mastitis cases, bulk tank milk somatic cell count, animal treatment costs, milk production, animal disposal costs, and production losses were collected. Monthly averages of temperature, relative humidity (RH), and rainfall in the region were obtained. The greatest loss was related to the drop in milk production, resulting in 63.8% of total losses, followed by animal disposal (29.5%), milk disposal (4.6%), and treating animals with mastitis (2.0%), totaling a 10.6% reduction in the annual gross income. There were negative correlations between the clinical mastitis rate and monthly RH and between subclinical mastitis and temperature; the occurrence of subclinical mastitis and average RH were positively correlated. Our findings showed that mastitis negatively impacted the economy and that climate influenced mastitis occurrence.

Asunto(s)

Enfermedades de los Bovinos , Mastitis Bovina , Bovinos , Animales , Femenino , Lactancia , Granjas , Brasil/epidemiología , Mastitis Bovina/epidemiología , Mastitis Bovina/tratamiento farmacológico , Industria Lechera , Leche , Recuento de Células/veterinaria , Enfermedades de los Bovinos/epidemiología

RESUMEN

BACKGROUND: Bovine mastitis is characterized by an inflammatory process in the mammary gland and represents one of the main diseases affecting a dairy herd. Management of mastitis is most commonly via antibiotics, but the rising incidence of multiple antibiotic resistance (MAR) means that additional options are needed. Homeopathic products can be administered in dairy farming for a range of clinical reasons and may be preferential due to the absence of residues. OBJECTIVES: The aim of this study was to assess the potential of a novel homeopathic complex medicine in managing bovine mastitis. METHODS: Twenty-four lactating Holstein cows with mastitis were divided into two groups: the homeopathic complex group received a homeopathic complex daily for 60 days at a dose of 20 g/d; the placebo group received the calcium carbonate vehicle without homeopathic medicines at the same dose and repetition. The main outcome measure was somatic cell count (SCC; cells/mL), with additional outcome measures including milk production (kg/d), milk constituents (percentage of protein, fat, lactose and total milk solids), and serum levels of cortisol, glucose, ammonia and lactic acid. All outcomes were measured at the beginning of the study and after 30 and 60 days. Milk samples were also collected from all animals at the beginning of the study, confirming a high (>0.2) MAR index for isolated bacterial cultures. RESULTS: Assessment of SCC showed a statistically significant difference favoring the homeopathic complex versus placebo group at day 60. A reduction in serum cortisol levels and an increase in fat, lactose and total milk solids in animals treated with the homeopathic complex at day 60 were also seen. Other outcome measures did not show statistically significant inter-group differences. CONCLUSION: The results of this non-randomized, open-label, placebo-controlled trial suggest the potential for a novel homeopathic complex medicine in management of multiple antibiotic-resistant bovine mastitis, thus offering dairy farmers an additional option to antibiotics and making dairy products safer for consumer health and milk production more sustainable.

Asunto(s)

Homeopatía , Mastitis Bovina , Materia Medica , Animales , Bovinos , Femenino , Antibacterianos/farmacología , Hidrocortisona , Lactancia , Lactosa , Mastitis Bovina/tratamiento farmacológico , Mastitis Bovina/epidemiología , Mastitis Bovina/microbiología , Materia Medica/farmacología

RESUMEN

Bovine mastitis is a multifactorial disease, caused mainly by bacteria, whose most traditional method of treatment is the use of antibiotics. However, incorrect administration of these drugs may lead to the emergence of resistant strains. The objective of this study was to identify the most common pathogens causing subclinical mastitis in the northwest State of Paraná, Brazil and establish their antimicrobial susceptibility profiles. A total of 507 foremilk samples were collected in 13 municipalities. Bacteria were identified and their profile of antimicrobial susceptibility were tested. The distribution of positive samples was not homogeneous among the cities. Streptococci were the most frequently genus observed (61%), followed by staphylococci (28%) and other genera (11%). Among streptococci and staphylococci, Streptococcus uberis and Staphylococcus aureus were the most frequently identified species, respectively. Overall, 40% of the isolates showed resistance to at least one of the antibiotics used in this study. A high proportion of cefoperazone resistant Staphylococcus spp. and bacitracin resistant Streptococcus were observed. The isolated microorganisms showed little resistance to enrofloxaxin. The results obtained show the importance of isolating the microorganism causing mastitis and testing its resistance to antibiotics before performing the treatment of the disease.

Asunto(s)

Enfermedades de los Bovinos , Mastitis Bovina , Staphylococcus aureus Resistente a Meticilina , Femenino , Animales , Bovinos , Leche , Brasil/epidemiología , Mastitis Bovina/epidemiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Staphylococcus

RESUMEN

Staphylococcus aureus is one of the most prevalent pathogens causing bovine mastitis in the world, in part because of its ease of adaptation to various hosts and the environment. This study aimed to determine the prevalence of S. aureus in Colombian dairy farms and its relationship with the causal network of subclinical mastitis. From thirteen dairy farms enrolled, 1288 quarter milk samples (QMS) and 330 teat samples were taken from cows with positive (70.1%) and negative California Mastitis Test (CMT). In addition, 126 samples from the milking parlor environment and 40 from workers (nasal) were collected. On each dairy farm, a survey was conducted, and the milking process was monitored on the day of sampling. S. aureus was identified in 176 samples, i.e., 138 QMS, 20 from teats, 8 from the milking parlor environment, and 10 from workers' nasal swabs. Isolates identified as S. aureus underwent proteomics (clustering of mass spectrum) and molecular (tuf, coa, spa Ig, clfA, and eno genes) analysis. Regarding proteomics results, isolates were distributed into three clusters, each with members from all sources and all farms. Concerning molecular analysis, the virulence-related genes clfA and eno were identified in 41.3% and 37.8% of S. aureus isolates, respectively. We provide evidence on the circulation of S. aureus strains with limited variability among animals, humans, and the environment. The parameters with the lowest compliance in the farms which may be implicated in the transmission of S. aureus are the lack of handwashing and abnormal milk handling.

Asunto(s)

Mastitis Bovina , Infecciones Estafilocócicas , Animales , Bovinos , Humanos , Femenino , Staphylococcus aureus/genética , Granjas , Colombia/epidemiología , Proteómica , Mastitis Bovina/epidemiología , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/veterinaria , Leche

RESUMEN

AIMS: Staphylococcus aureus is one of the most common pathogens associated with mastitis in dairy herds worldwide. This study evaluated the profile of virulence and antimicrobial resistance genes of spa type t605 methicillin-susceptible Staphylococcus aureus isolated from subclinical bovine mastitis in São Paulo, Brazil. METHODS AND RESULTS: A total of 57 S. aureus strains were screened by conventional PCR (Polymerase Chain Reaction) for 49 virulence genes. The most prevalent virulence genes detected were icaD (94.7%), fib (93%), fnbA (82.5%), clfA (80.7%), bap (78.9%), clfB (73.7%), icaA (66.7%), see (64.9%), and sed (61.4%). The blaZ (94.7%), aac6'aph2' (15.8%), and ant4 (12.3%) genes were the most common antimicrobial resistance genes; however, mecA and mecC genes were not found. All methicillin-susceptible S. aureus (MSSA) strains were characterized through spa and agr typing. The spa type t605 was found in all isolates. By agr typing, the most prevalent were type II (56.1%). Antimicrobial resistance was determined by the disk diffusion method, and 93% showed resistance to at least one antibiotic. Penicillin resistance was the most prevalent (87.7%), followed by tetracycline (12.3%), oxacillin (10.5%), and gentamicin (10.5%) resistance. CONCLUSION: Our study confirmed the spa type t605 as endemic, carrying a wide variety of virulence factors and high-level penicillin resistance. The profile seems to be associated with the colonization of MSSA and its persistence in subclinical mastitis.

Asunto(s)

Mastitis Bovina , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Animales , Bovinos , Femenino , Staphylococcus aureus , Antibacterianos/farmacología , Virulencia/genética , Meticilina , Mastitis Bovina/epidemiología , Farmacorresistencia Bacteriana/genética , Brasil , Infecciones Estafilocócicas/veterinaria , Infecciones Estafilocócicas/epidemiología , Factores de Virulencia/genética , Pruebas de Sensibilidad Microbiana

RESUMEN

This study aimed to evaluate the frequency of IgG antibodies against A. marginale, the occurrence of this bacterium by qPCR, and the effect of bovine anaplasmosis as a risk factor for clinical cases of retained placenta, mastitis, and abomasal displacement in dairy cattle. For that 179 Holstein cows out of three dairy herds, in the municipality of Sertão, Rio Grande do Sul, Brazil. These cows were on farms that were vulnerable to risk factors that are crucial to susceptibility among these animals to this intracellular hemoparasite. The mean seropositivity for A. marginale from the periods evaluated was 54% on farm A, 69.4% on farm B, and 27.3% on farm C. Molecular diagnosis was performed with qPCR and the mean positivity for A. marginale among the cows on farms A, B, and C in December 2017 was 34.6% (67/179). Infected animals showed clinical cases of retained placenta (6.1%), mastitis (6.1%), and abomasal displacement (0.5%). The association between positivity for anaplasmosis and these clinical cases was assessed through the odds ratio. Our results show that females with a positive qPCR assay for A. marginale had 52.48 times increased probability (OR) to develop clinical cases of retained placenta and mastitis (P < 0.001). These clinical cases negatively impact the productivity of positive females. Thus, implementing preventive and prophylactic control measures to ensure the sanitary quality of the herds is needed to avoid losses due to morbidity and mortality and diminish the economic losses suffered by farmers.

Asunto(s)

Anaplasmosis , Enfermedades de los Bovinos , Mastitis Bovina , Retención de la Placenta , Femenino , Embarazo , Bovinos , Animales , Anaplasmosis/epidemiología , Anaplasmosis/microbiología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Retención de la Placenta/epidemiología , Retención de la Placenta/veterinaria , Factores de Riesgo , Mastitis Bovina/epidemiología

RESUMEN

Genotyping of Staphylococcus aureus isolated from mastitis has become a fundamental tool to understand its complex epidemiology and to evaluate spillover events. The aim of this study was to describe the frequency of genotypes of the S. aureus strains isolated from intramammary infections by spa typing technique, and to evaluate the association between genotypes and the ability to form biofilm under in vitro conditions. Sixty-six strains of S. aureus recovered from bovines intramammary infections on 56 dairy herds located in 14 municipalities of the department of Antioquia were characterized. The majority of strains (65/66) were isolated from milk samples collected from dairy cows with subclinical intramammary infections. Nineteen different spa types were found in this study, t521 (19.70%), t267 (15.15%), and t605 (12.12%) being the most frequent. The strains from the t605 spa type showed the highest biofilm production. The high frequency of spa types with zoonotic potential found in this study, identified cattle as an important reservoir of theses clones for people in close proximity, such as milkers and consumers of unpasteurized dairy products.

Asunto(s)

Enfermedades de los Bovinos , Mastitis Bovina , Infecciones Estafilocócicas , Femenino , Bovinos , Animales , Staphylococcus aureus/genética , Leche , Mastitis Bovina/epidemiología , Variación Genética , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/veterinaria

RESUMEN

This study aimed to describe the epidemiological indexes of mastitis, milk quality and udder hygiene in the Compost Barn system, as well as to search for associations between isolated pathogens from milk with compost characteristics. Three dairy herds participated in the study, and the samples were collected during different periods on each farm. Individual milk samples were collected in duplicate for SCC analysis and microbiological culture. Environmental pathogens caused most cases of clinical mastitis on farm 2, and contagious pathogens caused the most cases on farm 1. Bed moisture was not associated with the incidence of environmental pathogens. Most of the animals remained in good udder hygiene during the study. Poor udder hygiene contributed to the increased incidence of environmental pathogens in one of the farms. A higher number of animals with a hygiene score of ≥ 2 were observed during the warmer and rainfall periods. There was no association between hygiene scores and somatic cell counts. The results suggest that pathogens isolated from milk in animals confined in Compost Barn under tropical climate are like other confinement systems adopted elsewhere. The year period influenced the udder hygiene score, reinforcing the importance of bed management throughout the year.

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O objetivo deste estudo foi descrever os índices epidemiológicos da mastite, da qualidade do leite e da higiene do úbere em animais confinados no sistema Compost Barn, bem como buscar associações entre patógenos isolados do leite e características do composto. Três rebanhos leiteiros participaram do estudo e as amostras foram coletadas em diferentes períodos em cada fazenda. Amostras individuais de leite foram coletadas em duplicata para análise de CCS e cultura microbiológica. Patógenos ambientais causaram a maioria dos casos de mastite clínica na fazenda 2, e na fazenda 1 a maioria dos casos foi em decorrência de patógenos contagiosos. Amostras de material da cama foram coletadas em duas fazendas para análise da densidade bacteriana e da umidade. A umidade da cama permaneceu dentro da faixa de controle durante o estudo e não foi associada à incidência de patógenos ambientais. A maioria dos animais permaneceu com boa higiene de úbere durante o estudo. A falta de higiene do úbere contribuiu para o aumento da incidência de patógenos ambientais em uma das fazendas. Durante o período mais quente e mais chuvoso, um número maior de animais com escore de sujidade ≥2 foi observado em todos os rebanhos. Não houve associação entre escore de sujidade e contagem de células somáticas em qualquer uma das três fazendas. Os resultados indicam que o perfil de patógenos isolados do leite em animais confinados em Compost Barn sob clima tropical é semelhante a outros sistemas de confinamento adotados em outros lugares. O período do ano influenciou o escore de higiene do úbere, o que reforça a importância do manejo da cama ao longo do ano.

Asunto(s)

Animales , Femenino , Bovinos , Leche/microbiología , Crianza de Animales Domésticos/métodos , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/epidemiología , Compostaje

RESUMEN

BACKGROUND: Staphylococcus aureus and Streptococcus agalactiae are the main cause of clinical mastitis in dairy cattle in Argentina, whereas coagulase-negative staphylococci (CNS) and environmental streptococci are the main cause of subclinical mastitis. Bacteria isolated from infected animals show increasing antimicrobial resistance. OBJECTIVES: This study aims to determine the antimicrobial resistance of staphylococci and streptococci isolated from milk with mastitis, and to genotypically characterize the methicillin-resistant (MR) staphylococci. METHODS: Isolation was performed on blood agar and identification was based on biochemical reactions. Antimicrobial susceptibility was according to the Clinical and Laboratory Standards Institute guidelines. The antimicrobial resistance genes, SCCmec type and spa type were detected by the polymerase chain reaction method. RESULTS: We isolated a total of 185 staphylococci and 28 streptococci from 148 milk samples. Among the staphylococcal isolates, 154 were identified as CNS and 31 as S. aureus. Among the 154 CNS, 24.6% (n = 38) were resistant to penicillin, 14.9% (n = 23) to erythromycin, 17.5% (n = 27) to clindamycin, 6.5% (n = 10) to cefoxitin and oxacillin. Among the S. aureus isolates, 16.1% (n = 5) were resistant to penicillin, 3.2% (n = 1) to cefoxitin and oxacillin (MRSA). Six MR isolates (5 CNS and 1 MRSA) were positive to the mecA gene, and presented the SCCmec IVa. The MRSA strain presented the sequence type 83 and the spa type 002. Among the 28 streptococcal isolates, 14.3% (n = 4) were resistant to penicillin, 10.7% (n = 3) to erythromycin and 14.3% (n = 4) to clindamycin. CONCLUSIONS: The present findings of this study indicate a development of antimicrobial resistance in main bacteria isolated from cows with mastitis in Argentina.

Asunto(s)

Enfermedades de los Bovinos , Mastitis Bovina , Femenino , Bovinos , Animales , Staphylococcus , Antibacterianos/farmacología , Staphylococcus aureus , Cefoxitina , Clindamicina , Argentina/epidemiología , Farmacorresistencia Bacteriana , Mastitis Bovina/epidemiología , Streptococcus , Oxacilina , Eritromicina

RESUMEN

In this study, we evaluated the main risk factors for the occurrence of bovine mastitis, in the southeastern of Pará, in the Brazilian Amazon. We surveyed 91 dairy farmers to identify management practices and bovine breed characteristics. From each farm, 50 mL of milk sample was collected for microbiological analysis and somatic cell count (SCC). Depending on the management practices and breed, a logit model was used to determine the odds ratio of subclinical mastitis (SCM) occurrence. In irrigated pastures, an SCM-associated risk factor, the occurrence of SCM was 5.03 times higher than that in the non-irrigated pastures. Similarly, in Girolando breed herds, the occurrence of SCM increased by 5.8 times compared to the crossbred herds. Moreover, the occurrence of mastitis was 33 times higher in farms using common cloths for drying teats than in farms using paper towels. Therefore, adoption of better management practices can lead to SCC reduction, milk quality improvement and a guarantee to contain SCC within prescribed Brazilian limits for the Amazon region.

Asunto(s)

Enfermedades de los Bovinos , Mastitis Bovina , Animales , Bovinos , Femenino , Recuento de Células/veterinaria , Industria Lechera , Mastitis Bovina/epidemiología , Mastitis Bovina/microbiología , Leche/microbiología , Prevalencia , Factores de Riesgo , Brasil

RESUMEN

Diptera (Insecta) are able to transmit approximately 200 pathogenic microorganisms to humans and animals, causing more than 65 diseases, including bovine mastitis, which constitutes a major cause of economic losses in the dairy industry. In this scenario, 217 adult specimens of Diptera were collected from nine farms and identified to the family and/or species level. Of the 11 families recorded, Muscidae was the most prevalent (152 out of 217; 70%). All Diptera specimens were subjected to microbiological culture using conventional and selective media, and isolates were then identified at the species level by mass spectrometry. In total, 275 microorganisms were identified, with a predominance of pathogens related to environmental bovine mastitis (166/275 = 60·4%), that is, Enterococcus species (70/275 = 25·4%) and Escherichia coli (49/275 = 17·8%). Nontraditional agents related to bovine mastitis (called miscellaneous) were detected in 28% (77/275), as well as microorganisms with well-known zoonotic behaviour (e.g. Bacillus cereus). This is study contributes with knowledge of diversity of microorganisms carried by Diptera in the dairy environment, including pathogens associated with environmental and contagious bovine mastitis, and agents with human relevance. To our knowledge, a three-part chromogenic selective medium used to microbial culture of milk on farms was used for the first time to identification of pathogens in Diptera.

Asunto(s)

Dípteros , Mastitis Bovina , Bovinos , Animales , Femenino , Humanos , Mastitis Bovina/epidemiología , Mastitis Bovina/microbiología , Leche/microbiología , Prevalencia , Escherichia coli , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos

RESUMEN

The objectives were to study the diversity of Enterococcus spp. isolated from mastitis cases, milking equipment and the environment of dairy cows; and to determine in vitro resistance of isolates to antimicrobials that are relevant to human and animal health. Ten dairy farms were visited to collect samples from mastitis cases, faeces, bedding, aisles, water and milking equipment. Identification of Enterococcus at the species level and antimicrobial resistance testing was performed by MALDI-TOF and the disk-diffusion method, respectively. Of 365 isolates, Enterococcus hirae was the most prevalent, being more likely to be isolated from faeces than from milk (odds ratio (OR) = 39·2), liners (OR = 5·4) or bedding (OR = 2·2). Enterococcus saccharolyticus was the most prevalent in milk samples. The chances of isolating Enterococcus faecalis from milk were higher than from aisles (OR = 12·5), faeces (OR = 5·3), bedding (OR = 3·6) or liners (OR = 3·0). The odds of isolating Enterococcus faecium from faeces were higher than from liners (OR = 7·3), bedding (OR = 2·5) or aisles (OR = 2·4). Of 360 tested isolates, 1·9, 0·3 and 0·6% were resistant to penicillin, vancomycin and teicoplanin, respectively. Our results suggest that Enterococcus species can occupy specific ecological niches on dairy farms and pose a risk to public and animal health.

Asunto(s)

Mastitis Bovina , Leche , Animales , Antibacterianos/farmacología , Bovinos , Farmacorresistencia Bacteriana , Enterococcus , Femenino , Humanos , Mastitis Bovina/epidemiología , Pruebas de Sensibilidad Microbiana , Penicilinas , Teicoplanina , Vancomicina , Agua

RESUMEN

INTRODUCTION: Bovine mastitis is the most common disease affecting the dairy industry, with staphylococci being considered as one of the most significant and prevalent causes. This study aimed to assess the presence of staphylococcal subclinical mastitis (SCM) in Uruguayan dairy farms and to identify Staphylococcus aureus (SA) and non-aureus staphylococci (NAS) in milking cows. In addition, the antibiotic susceptibility of isolated staphylococci was evaluated. METHODOLOGY: We tested 546 apparently healthy milking cows from 11 farms for detecting SCM using the California Mastitis Test (CMT). The cows were not treated with antibiotics. CMT-positive samples were cultured, and colonies compatible with Staphylococcus spp. were further identified through molecular techniques. The susceptibility of the Staphylococcus spp. isolates against thirteen antibiotics was determined using the disk diffusion method. RESULTS: Subclinical staphylococcal mastitis was present in almost all (82%) farms. SA (n = 39) was more common than NAS (n = 9) in the 48 samples tested. Isolates exhibited resistance to one, two, and even three different antibiotics. Resistance to penicillin was the most frequent among SA (23/39) and NAS (4/9). No staphylococci isolates exhibited resistance to cefoxitin, vancomycin, trimethoprim-sulfamethoxazole, erythromycin, or clindamycin. CONCLUSIONS: Staphylococcal SCM is one of the most common diseases in Uruguayan dairy farms. SA was the prevalent pathogen, however SA and NAS mastitis coexisted in many farms. NAS were identified and its distribution was similar to other countries. Penicillin had the highest and most frequent percentage of resistance.

Asunto(s)

Mastitis Bovina , Infecciones Estafilocócicas , Animales , Antibacterianos/farmacología , Bovinos , Granjas , Femenino , Humanos , Mastitis Bovina/epidemiología , Leche , Penicilinas , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus , Staphylococcus aureus

RESUMEN

The aim of this study was to identify emergent pathogens associated with bovine mastitis in northeastern Brazil and to characterize them for phenotypic and genotypic resistance to antimicrobials. A total of 321 milk samples from cows with subclinical mastitis were collected, and the isolates obtained in culture were identified using matrix-associated laser desorption-ionization - time of flight mass spectrometry. Phenotypic and genotypic antimicrobial resistance tests were performed. We identified 72 bacteria considered emergent in the study region: Enterococcus faecalis (26.3%; 19/72), Streptococcus agalactiae (22.2%; 16/72), Enterococcus faecium (20.0%; 15/72), Escherichia coli (6.9%; 5/72), 6.9% (5/72) Lactococcus garvieae (6.9%; 5/72), Acinetobacter baumannii (5.5%; 4/72), Bacillus subtilis (1.3%; 1/72), Kocuria marina (1.3%; 1/72), Macrococcus caseolyticus (1.3%; 1/72), Microbacterium resistens (1.3%; 1/72), Micrococcus luteus (1.3%; 1/72), Streptococcus dysgalactiae (1.3%; 1/72), Streptococcus hyovaginalis (1.3%; 1/72) and Streptococcus pluranimalium (1.3%; 1/72). The antibiogram revealed the following resistance profiles: ampicillin (77.7%; 56/72), cefoxitin (69.4%; 50/72), erythromycin (61.1%; 44/72), oxacillin (63.8%; 46/72), penicillin (79.1%; 57/72), tetracycline (63.8%; 46/72), gentamicin (25.0%; 18/72), and vancomycin (20.8%; 15/72). Of the isolates, 83.4% (60/72) showed multiple resistance to antimicrobials. The tetM gene was identified in 43.0% (31/72) of the isolates, followed by tetL (31.9%; 23/72), and blaZ (26.3%; 19/72). 83.4% (60/72) of the isolates presented a multiple antimicrobial resistance index higher than 0,2. Emergent bacteria with zoonotic and multiresistant potential occur in cows with mastitis in northeastern Brazil. It is necessary to monitor the occurrence of these and other bacteria in livestock environments and develop control strategies to prevent their spread.

Asunto(s)

Antiinfecciosos , Enfermedades de los Bovinos , Mastitis Bovina , Animales , Antibacterianos/farmacología , Bacterias/genética , Brasil/epidemiología , Bovinos , Farmacorresistencia Bacteriana/genética , Femenino , Mastitis Bovina/epidemiología , Mastitis Bovina/microbiología , Pruebas de Sensibilidad Microbiana/veterinaria , Leche/microbiología

RESUMEN

This study evaluated (a) the efficacy of an association between injectable antibiotic therapy and sealant (ATBS) on milk yield (MY), somatic cell count (SCC), and prevalence of intramammary infections (IMI); and (b) the efficacy of gonadotropin-releasing hormone (GnRH) on follicular cyst (FCs) resolution (cyclicity at the 45th day in milk; DIM) and cumulative pregnancy rate (CPR) in heifers submitted to a lactation induction protocol (LIP). A total of 114 crossbred (Holstein × Jersey) heifers, with 34.7 ± 4.8 months and 439 ± 56.35 kg were submitted to LIP. On the 5th day of the LIP, the heifers were assigned to (i) ATBS (n = 57) with 7 mg/kg of norfloxacin associated with sealant and (ii) Control 1 (n = 57; CONT1) with no treatments. Lactation began on the 21st day of LIP and the 15th DIM, FCs were diagnosed and 106 heifers were randomized into two treatment groups with 53 heifers each: (i) GnRH (5 mL injectable GnRH) and (ii) Control 2 (CONT2; no treatment). Of the 114 heifers initially induced, 83.33% (n = 95) responded to LIP with an average MY of 15.19 kg/milk/day during 22 weeks of lactation. In the first 14 DIM, the IMI prevalence was 18% and 28% for heifers ATBS and CONT1 treated, respectively. Additionally, coagulase-negative Staphylococcus was the most frequently isolated group of pathogens. Mammary quarters that received ATBS treatment had a lower risk of IMI and SCC than CONT1. The cyclicity at 45 DIM was 68% (ATBS) and 35% (CONT1), and 57% and 46% for animals in the GnRH and CONT2. CPR was 60% in the ATBS group and 89% in CONT1, but GnRH treatment did not affect the CPR. In conclusion, LIP was effective in stimulating MY in heifers, and the IMI prevalence decreased with ATBS treatment. Also, the use of GnRH did not affect the FC regression, cyclicity at 45 DIM, and CPR.(AU)

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Este estudo avaliou a (i) eficácia da associação entre antibioticoterapia injetável e selante interno de tetos (ATBS) na produção de leite (PL), contagem de células somáticas (CCS), e prevalência de infecções intramamárias (IIM); e (ii) eficácia do hormônio liberador de gonadotrofina (GnRH) na resolução de cistos foliculares (CFs), ciclicidade ao 45º dia em lactação (DEL) e taxa de prenhez cumulativa (TPC) em novilhas submetidas a um protocolo de indução de lactação (PIL). Um total de 114 novilhas mestiças (Holandês × Jersey), com 34,7 ± 4,8 meses e 439 ± 56,35 kg foram submetidas ao PIL. No 5º dia do PIL, as novilhas receberam: (i) ATBS (n = 57) com 7 mg/kg de norfloxacina associada ao selante interno de tetos e (ii) Controle 1 (n = 57; CONT1) sem tratamento. A lactação teve início no 21º dia do PIL e no 15º DEL, foram diagnosticados CFs e 106 novilhas foram agrupadas em dois grupos de tratamento com 53 novilhas em cada: (i) GnRH (5 mL de GnRH injetável) e (ii) Controle 2 (CONT2; sem tratamento). Das 114 novilhas inicialmente induzidas, 83,33% (n = 95) responderam ao PIL com PL média de 15,19 kg/leite/d durante 22 semanas de lactação. Nos primeiros 14 DEL a prevalência de IIM foi de 18% e 28% para as novilhas tratadas com ATBS e CONT1, respectivamente. Além disso, estafilococos coagulase negativa foram o grupo de patógenos mais frequentemente isolados. Quartos mamários tratados com ATBS tiveram menor risco (0,56) de IIM e menor CCS do que CONT1. A ciclicidade a 45 DEL foi de 68% (ATBS) e 35% (CONT1), e 57% e 46% para os animais no GnRH e CONT2. A TPC foi de 60% no grupo ATBS e 89% no CONT1, porém o tratamento com GnRH não afetou a TPC. Em conclusão, o PIL foi eficaz em estimular a PL em novilhas tardias e a prevalência de IIM diminiuiu com o tratamento ATBS. Além disso, o uso de GnRH não afetou a regressão de CF, ciclicidade em 45 DEL e a TPC.(AU)

Asunto(s)

Animales , Masculino , Embarazo , Lactancia/fisiología , Hormona Liberadora de Gonadotropina/farmacología , Mastitis Bovina/epidemiología , Antiinfecciosos/uso terapéutico , Quiste Folicular/diagnóstico , Bovinos/fisiología , Norfloxacino/administración & dosificación , Recuento de Células/veterinaria , Leche/fisiología

RESUMEN

Considering the high prevalence of subclinical mastitis and its impacts on milk production, thematic studies are need to provide strategic data for its control. This study aimed at investigating the most frequent microorganisms associated with subclinical mastitis in dairy cows in Brazil through compiling the occurrence of the etiological agents and their sensitivity to antibiotics. The systematic review includes articles published between 2009 and 2019. Fiftyseven articles evaluating 22,287 milk samples were selected. The number of publications and the sample size were not homogeneous among Brazilian regions. Most of the studies and sampling were conducted in Rio Grande do Sul, whereas no studies were found in some states in the north and mid­west regions. The most frequent pathogen was Staphylococcus spp. It was isolated in all studies and had an average prevalence of 49% in the analyzed samples. Resistance to penicillin was the most frequent microbial resistance found in Brazil, with an average of 66% among the isolates evaluated. Moreover, bacterial resistance to cephalexin, cefoperazone, erythromycin, gentamicin, neomycin, penicillin, tetracycline, and trimethoprim increased over the research period. Given the territorial extension, the etiological diversity, and the lack of studies with a representative sample, the compilation of scientific data must be interpreted with caution. Regions where a greater number of studies were conducted and with numerous samples, such as the South, provided a comprehensive scenario that is closer to reality. Nevertheless, although decision making on the farm cannot be replaced by scientific studies, it can be supported by such efforts.

Asunto(s)

Enfermedades de los Bovinos , Mastitis Bovina , Animales , Bovinos , Femenino , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Brasil/epidemiología , Mastitis Bovina/epidemiología , Penicilinas

RESUMEN

The objective was to assess the prevalence and influence of clinical and subclinical mastitis during the service period of cows in a herd in Tarumirim (MG), from October 2019 to May 2020. Around 65 Gir x Holstein and Guzerá x Holstein lactating crossbred cows were evaluated. Subclinical mastitis was diagnosed by means of the California Mastitis Test (CMT), and clinical mastitis, by means of the strip cup test and the animals' clinical signs. Pregnancy after calving was diagnosed by the rectal palpation method, with the aid of ultrasound. The time from calving to conception was considered as the service time. The prevalence rates of clinical and subclinical mastitis were 2.9 and 63.7%, respectively, throughout the experimental period. The mean service period was shorter (p<0.05) in healthy cows (63.1 days) than in cows with subclinical mastitis (88.5 days) and clinical mastitis (111.2 days). The service period increased by 30.9 days for each mammary quarter with clinical mastitis (p<0.05). With each increase in the degree and days of duration of clinical and subclinical mastitis, the service period rose by 25.4 and 6.5 days, and 8.5 and 0.6 days, respectively (p<0.05). Therefore, mastitis increases the service period of dairy cows. Good milking hygiene and animal handling practices should be adopted in order to reduce the prevalence of mastitis in the herd.(AU)

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Objetivou-se avaliar a prevalência e influência da mastite clínica e subclínica no período de serviço de vacas em um rebanho de Tarumirim (MG), ao longo de outubro de 2019 a maio de 2020. Em torno de 65 vacas mestiças Gir x Holandês e Guzerá x Holandês em lactação foram avaliadas. A mastite subclínica foi diagnosticada por meio de California Mastitis Test(CMT) e a mastite clínica por meio do teste da caneca e sinais clínicos dos animais. O diagnóstico de gestação após o parto foi realizado pelo método de palpação retal, com auxílio de ultrassom. O tempo do parto até a concepção foi considerado como o tempo de serviço. As prevalências de mastite clínica e subclínica foram de 2,9 e 63,7%, respectivamente, ao longo do período experimental. O período de serviço médio foi menor (p<0,05) em vacas sadias (63,1 dias) que em vacas com mastite subclínica (88,5 dias) e clínica (111,2 dias). O período de serviço aumentou 30,9 dias a cada quarto mamário com mastite clínica (p<0,05). A cada aumento do grau e dias de duração da mastite clínica e subclínica, o período de serviço aumentou 25,4 e 6,5 dias e 8,5 e 0,6 dias, respectivamente (p<0,05). Portanto, a mastite aumenta o período de serviço de vacas leiteiras. Boas práticas de higiene de ordenha e manejo dos animais devem ser adotadas para reduzir a prevalência de mastite no rebanho.(AU)

Asunto(s)

Animales , Femenino , Embarazo , Palpación/métodos , Lactancia/fisiología , Mastitis Bovina/epidemiología , Brasil , Bienestar del Animal , Bovinos , Periodo Posparto