RESUMEN
Clinical mastitis (CM) is the most common microbial disease treated in dairy cows. We analyzed the antimicrobial usage in cows with CM (n = 11,420) in large dairy herds (n = 43) in Estonia. CM treatment data were collected during a 12-month study period. The antimicrobial usage was observed during the 21 days from the initiation of treatment, and the incidence of antimicrobial-treated CM was calculated for each study herd. The effect of intramammary (IMM), systemic, and combined (systemic and IMM) penicillin treatment of CM on the post-treatment somatic cell count (SCC) was analyzed using the treatment records of 2222 cows from 24 herds with a mixed multivariable linear regression model. The median incidence of antimicrobial-treated CM was 35.8 per 100 cow-years. Procaine benzylpenicillin and marbofloxacin were used in 6103 (35.5%, 95% CI 34.8-36.2) and 2839 (16.5%, 95% CI 16.0-17.1) CM treatments, respectively. Post-treatment SCC was higher after IMM penicillin therapy compared to systemic or combination therapy. Treatment of CM usually included first-choice antimicrobials, but different antimicrobial combinations were also widely used. The effect of procaine benzylpenicillin to post-treatment SCC was dependent on the administration route, cow parity, and days in milk. Further studies should evaluate the factors affecting veterinarians' choice of antimicrobial used in the treatment of CM.
RESUMEN
We aimed to identify the dynamics of the within-herd prevalence of Mycoplasma (M.) bovis intramammary infection (IMI) in four dairy herds, estimate prevalence of M. bovis in colostrum and clinical mastitis cases and compare M. bovis strains from calves' respiratory and cow clinical mastitis samples. Within a six-month study period, cow composite milk samples (CMS) were collected three times during routine milk recording, first milking colostrum samples from all calving cows and udder quarter milk samples from clinical mastitis cases. Calf respiratory samples were collected from calves with respiratory disease. Pooled milk samples were analysed for M. bovis with the Mastitis 4B polymerase chain reaction (PCR) test kit (DNA Diagnostic A/S). Prevalence estimates were calculated with Bayesian framework in R statistical programme. cg-MLST was used for M. bovis genotyping. In Herd I and II first testing M. bovis IMI within-herd prevalence (95 % credibility interval (CI)) was 4.7 % (2.9; 6.8) and 3.4 % (2.3; 4.6), changing to 1.0 % (0.1; 1.7) and 0.8 % (0.1; 1.4) in Herd I and 0.4 % (0.0; 0.7) in Herd II at the next samplings. In Herd III and IV first testing M. bovis IMI within-herd prevalence was 12.3 % (9.7; 15.2) and 7.8 % (6.2; 9.5), changing to 4.6 % (3.0; 6.4) and 3.2 % (1.9; 4.8) in Herd III and to 2.8 % (1.9; 3.8) and 4.9 % (3.6; 6.4) in Herd IV at the next samplings. The estimated prevalence of M. bovis in colostrum ranged between 1.7 % (0.2; 2.8) and 4.7 % (2.7; 7.1) and in clinical mastitis cases between 3.7 % (1.7; 6.4) and 11.0 % (7.5; 15.2) in the study herds. M. bovis strains isolated from cows and calves clustered within herds indicating possible transmission of M. bovis between dairy cows and calves. Prevalence of M. bovis in colostrum and clinical mastitis cases as well as the within-herd prevalence of M. bovis IMI was low in endemically infected dairy herds.
Asunto(s)
Glándulas Mamarias Animales/microbiología , Mastitis Bovina/epidemiología , Mastitis Bovina/microbiología , Infecciones por Mycoplasma/veterinaria , Mycoplasma bovis/genética , Animales , Técnicas de Tipificación Bacteriana , Teorema de Bayes , Bovinos , Calostro/microbiología , Estudios Transversales , Industria Lechera , Estonia/epidemiología , Femenino , Genotipo , Tipificación de Secuencias Multilocus , Infecciones por Mycoplasma/epidemiología , Mycoplasma bovis/clasificación , PrevalenciaRESUMEN
We aimed to evaluate the elimination of 4 different mastitis pathogens, Streptococcus agalactiae, Mycoplasma bovis, Staphylococcus aureus, and Streptococcus uberis, from infected udder quarters during the dry period using quantitative PCR. The second purpose of this study was to evaluate the association between milk haptoglobin (Hp) concentration and the presence of udder pathogens (Strep. agalactiae, Staph. aureus, M. bovis, and Strep. uberis) in udder quarter milk samples before and after dry period. Aseptic udder quarter milk samples (n = 1,001) were collected from 133 dairy cows at dry off and at the first milking after calving from 1 large dairy herd. Bacterial DNA of Strep. agalactiae, Staph. aureus, Strep. uberis, and M. bovis in the udder quarter milk samples was identified with commercial quantitative PCR analysis Mastitis 4B (DNA Diagnostic A/S, Risskov, Denmark). Milk Hp concentration (mg/L) was measured from udder quarter milk samples. The elimination rates during the dry period for M. bovis, Staph. aureus, Strep. agalactiae, and Strep. uberis were 86.7, 93.6, 96.2, and 100.0%, respectively. The new IMI rate was 3.0% for M. bovis, 2.9% for Staph. aureus, 2.4% for Strep. agalactiae, and 3.1% for Strep. uberis. The milk Hp concentration was significantly higher in udder quarter milk samples with blood and in samples positive for Strep. agalactiae at dry off and for Staph. aureus postcalving. Elevated milk Hp concentration was not associated with the presence of M. bovis in the udder quarter milk samples. In conclusion, elimination of Staph. aureus, Strep. agalactiae, and Strep. uberis during the dry period was high; the elimination of M. bovis from infected udder quarters was lower, but probably spontaneous. Additionally, milk Hp concentration may be used as a marker for udder inflammation when combined with the bacteriological results at dry off and postpartum.
Asunto(s)
Mastitis Bovina/prevención & control , Infecciones por Mycoplasma/veterinaria , Infecciones Estafilocócicas/veterinaria , Infecciones Estreptocócicas/veterinaria , Animales , Bovinos , Dinamarca , Femenino , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/microbiología , Leche/microbiología , Infecciones por Mycoplasma/prevención & control , Mycoplasma bovis/aislamiento & purificación , Infecciones Estafilocócicas/prevención & control , Infecciones Estreptocócicas/prevención & control , Streptococcus/aislamiento & purificación , Streptococcus agalactiae/aislamiento & purificaciónRESUMEN
Subclinical mastitis is one of the major health problems in dairy herds due to decreased milk production and reduced milk quality. The aim of this study was to examine the within-herd prevalence of subclinical intramammary infection caused by Mycoplasma bovis and to evaluate associations between M. bovis and cow daily milk yield, udder health, and milk composition. Individual cow composite milk samples (n = 522) were collected from all lactating dairy cows in 1 Estonian dairy farm in November 2014. Daily milk yield, days in milk, and parity were recorded. Collected milk samples were analyzed for somatic cell count, milk protein, fat, and urea content. The presence of M. bovis, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus uberis in the milk samples was confirmed by quantitative PCR analysis. The within-herd prevalence of M. bovis was 17.2% in the study herd. No association was observed between days in milk and parity to the presence of M. bovis in milk. According to linear regression analysis, the daily milk yield from cows positive for M. bovis was on average 3.0 kg lower compared with cows negative for M. bovis. In addition, the presence of M. bovis in milk samples was significantly associated with higher somatic cell count and lower fat and urea content compared with milk samples negative for M. bovis. In conclusion, subclinical M. bovis intramammary infection is associated with decreased milk yield and lower milk quality.