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1.
Vet Parasitol ; 273: 112-121, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31476666

RESUMO

Toxoplasma gondii is the parasite responsible for toxoplasmosis, a highly prevalent zoonosis that affects humans and warm-blooded animals. Faeces of infected cats can contain millions of T. gondii oocysts, which remain infectious in the environment for months. Sites repeatedly used by cats for defecation ('latrines') are recognised as hotspots of T. gondii soil contamination, but this contamination varies from one latrine to another. To understand this spatial heterogeneity, camera traps were deployed in 39 cat latrines on three dairy farms with high-density cat populations and programmed to record visits during sixteen 10-day sessions, rotating between three farms over a period of a year. Generalized Linear Mixed Models were used to test the effects of cat sexual maturity, latrine location and season on the number of cat faeces deposited and on the number of cats defecating per latrine, as determined from the analysis of 41,282 video recordings. Sexually immature cats defecated 6.60-fold (95% CI = [2.87-15.25]) more often in latrines located close to a feeding site than in other latrines. This pattern was also observed for mature males (odds ratio [OR] = 9.42, 95% CI = [3.29-26.91]), especially during winter, but not for mature females (OR = 1.77, 95% CI = [0.80-3.94]). The number of defecating cats was also 2.67-fold (95% CI = [1.66-4.30], P < 0.001) higher in latrines located close to a feeding point than in those located far from it, regardless of cat category and season. Visits by intermediate T. gondii hosts (micromammals, birds and others) were also recorded. Out of the 39 latrines, 30 (76.92%) were visited by at least one intermediate host during the study period, and some latrines were highly frequented (up to 8.74 visits/day on average). These results provide evidence that the location of food resources in dairy farms influences the latrine use pattern by cats. Highly frequented latrines can be of high risk of T. gondii infection for definitive and intermediate hosts.


Assuntos
Comportamento Animal/fisiologia , Doenças do Gato/transmissão , Solo/parasitologia , Toxoplasmose Animal/transmissão , Animais , Gatos , Indústria de Laticínios , Feminino , Interações Hospedeiro-Parasita , Modelos Lineares , Densidade Demográfica
2.
Schweiz Arch Tierheilkd ; 161(9): 533-544, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31488394

RESUMO

INTRODUCTION: The aim of the present study was to determine the effects of selective dry cow treatment (SDCT) on udder health in Swiss dairy farms compared to a blanket dry cow treatment (BDCT). Cows with a somatic cell count (SCC) of less than 250'000 cells/ml and after BDCT in the previous dry period were selected. These animals received a SDCT in the subsequent dry period. Cows with less than 150,000 cells/ml or a negative California mastitis test (CMT) received either no treatment (group oB) or an internal teat sealant (group ZV) in all teats. Cows with more than 150,000 cells/ml or a positive CMT were treated with antibiotics and teat sealants (group ZV+AB). The SCC before and after the dry period were determined. In addition, the incidence of mastitis treatments in the dry period and the first 100 days of the following lactation as well as rates of new intramammary inflammations and healing thereof were determined. Data from 115 cows were available for evaluation. The SCC postpartum of all cows after SDCT did not differ from those after BDCT in the previous year. In the group oB the SCC was significantly higher than in the previous year. While the group ZV+AB showed a significant decrease of SCC during the dry period, the other two groups showed an increase (p < 0.0001). In the group oB, the proportion of mastitis treatments increased from 0% after BDCT to 28% after SDCT without any udder treatment (p < 0.05). Due to the increasing problem of antimicrobial resistance, SDCT is a valuable alternative to the BDCT. In the present study the antibiotic consumption could be reduced by 63%, while the udder health after SDCT did not deteriorate. If cows with low SCC are dried off without antibiotics the end of lactation, it is beneficial to protect the udder during the dry period with a teat sealant.


Assuntos
Indústria de Laticínios/métodos , Glândulas Mamárias Animais , Mastite Bovina/prevenção & controle , Animais , Antibacterianos/administração & dosagem , Bovinos , Contagem de Células/veterinária , Feminino , Incidência , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/tratamento farmacológico , Mastite Bovina/epidemiologia , Suíça/epidemiologia
3.
Med Lav ; 110(4): 271-277, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31475688

RESUMO

BACKGROUND: Occupational tasks characterized by repetitive, awkward and forceful movements of the hand and wrist may heighten the risk of carpal tunnel syndrome (CTS) among dairy parlor workers. Median nerve impairment can be investigated with ultrasonography (US) and nerve conduction studies (NCS) but a structured questionnaire may help identify early symptoms. OBJECTIVES: Our objectives were to: a) compare the sensitivity of US investigations and NCS to detect early signs of CTS; b) explore the correlation of the results of these two tests with CTS symptoms obtained from the administration of a targeted questionnaire. METHODS: Forty male milking parlor workers were recruited. The study protocol included: 1) the identification of characteristic CTS symptoms through a targeted questionnaire; 2) US imaging of the carpal tunnel inlet (using a portable ultrasound device; 3) NCS of the distal median nerve. RESULTS: The symptom questionnaire was considered positive if at least one CTS symptom was present within two weeks prior to the examination. The symptom questionnaire showed a high level of specificity (92,6%) and sensitivity (61%) when compared with NCS results. Ultrasound results revealed a prevalence of median neuropathy of 55%, but when compared to NCS, the ultrasound showed quite low predictive values (NPV of 37% and PPV of 38%). DISCUSSION: The symptom questionnaire was associated with the median nerve pathology often seen in CTS. Moreover, the study results have shown the questionnaire to be the most effective screening method when compared to ultrasound.


Assuntos
Síndrome do Túnel Carpal , Indústria de Laticínios , Doenças Profissionais , Síndrome do Túnel Carpal/diagnóstico , Síndrome do Túnel Carpal/etiologia , Humanos , Itália , Masculino , Nervo Mediano , Condução Nervosa , Doenças Profissionais/etiologia , Sensibilidade e Especificidade
4.
Vet Parasitol ; 273: 36-44, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31442891

RESUMO

Rhipicephalus (Boophilus) microplus ticks cause major constraints to public and livestock health, and serious economic losses. It is well known that the immune response to infestations with cattle ticks is influenced by the host genetic background leading to distinct immunological profiles between bovine hosts genetically susceptible and resistant. The influence of Bos indicus (Bi) and Bos taurus (Bt) maternal lineage ancestry of mitochondrial DNA in the profile of the immune response of Zebu cattle to ticks remains unknown. The present work evaluated the hematological parameters and the immune response profile in the peripheral blood of a Guzerat dairy herd, further categorized into two maternal lineage ancestry subgroups (Bi-mtDNA and Bt-mtDNA) after experimental infestation with larvae of R. microplus. Our data demonstrated that although hematological and erythrogram analysis showed a similar profile throughout, some cell populations present a distinct profile between the groups. Especially MON, CD335+ and CD8+ T-cells are predominant in Bi-mtDNA. Moreover, an overall picture of R. microplus infestation demonstrated that Bi-mtDNA presented a more efficient and earlier innate immune response. Bi-mtDNA showed a greater number of connections with R. microplus counts and also with the CD25+ activation marker of the immune response. Bi-mtDNA showed greater number of connections, with an important participation of the innate immune while Bt-mtDNA showed a delay in the immune response. Elucidating the mechanisms by which resistant animals prevent heavy tick infestation is a crucial step in the development of predictive biomarkers for tick resistance for use in selective breeding programs, and is also potentially useful for the development of anti-tick vaccines.


Assuntos
Doenças dos Bovinos/imunologia , Interações Hospedeiro-Parasita/imunologia , Imunidade Inata/imunologia , Rhipicephalus/imunologia , Infestações por Carrapato/veterinária , Animais , Cruzamento , Bovinos , DNA Mitocondrial/genética , Indústria de Laticínios , Feminino , Perfilação da Expressão Gênica , Linfócitos T/imunologia , Infestações por Carrapato/imunologia
5.
Exp Parasitol ; 205: 107735, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31381870

RESUMO

Two experiments were performed to determine whether oral administration of copper oxide capsules controlled helminthic infections in Lacaune sheep without acute collateral effects on animal health. In experiment 1, 48 multiparous lactating sheep (60.1 ±â€¯8.5 kg) were stratified according to initial number of eggs (Haemonchus contortus) per gram of feces (EPG) and were assigned randomly to 1 of two treatments (24 sheep/treatment): no oral administration (control) or oral administration of two copper capsules (treated; approximately 58 mg copper/kg body weight). Blood and fecal samples were collected on days 0, 15 and 45. Animals treated with copper capsules showed lower of EPG, eosinophils, acetylcholinesterase (AChE) in whole blood, and lower butyrylcholinesterase (BChE) activity in serum. Treated sheep had higher erythrocyte numbers, hemoglobin concentrations, hematocrit, and lymphocyte numbers. In experiment 2, 12 male lambs negative for helminths and coccidia were assigned randomly to one of two treatments (six lambs/treatment): control or treated (one copper capsule; approximately 58 mg copper/kg body weight); the experiment was designed to determine whether the results of experiment 1 were due to treatment or parasitism. Blood samples were collected on days 0, 5, 10 and 15 and fecal samples were collected on days 0, 7 and 15. Treated animals showed greater concentrations of lymphocytes; however, treatment had no effect on other hemogram variables, AChE and BChE activities, or levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, creatinine, urea, albumin, total protein, and reactive oxygen species. These data suggest that copper capsules in dairy sheep efficiently controlled H. contortus infections. Treatment was not harmful to lambs during the first 15 days, i.e. there were no signs of acute toxicity.


Assuntos
Cobre/administração & dosagem , Hemoncose/veterinária , Helmintíase Animal/tratamento farmacológico , Lactação , Doenças dos Ovinos/tratamento farmacológico , Acetilcolinesterase/sangue , Administração Oral , Animais , Butirilcolinesterase/sangue , Cápsulas , Cobre/uso terapêutico , Indústria de Laticínios , Resíduos de Drogas , Eosinófilos/efeitos dos fármacos , Contagem de Eritrócitos/veterinária , Fezes/parasitologia , Feminino , Hemoncose/tratamento farmacológico , Hemoncose/prevenção & controle , Helmintíase Animal/sangue , Helmintíase Animal/prevenção & controle , Hematócrito/veterinária , Hemoglobinas/análise , Contagem de Linfócitos/veterinária , Masculino , Leite/química , Contagem de Ovos de Parasitas/veterinária , Paridade , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/sangue , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/prevenção & controle
6.
Genet Sel Evol ; 51(1): 43, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409294

RESUMO

BACKGROUND: Random regression models (RRM) are widely used to analyze longitudinal data in genetic evaluation systems because they can better account for time-course changes in environmental effects and additive genetic values of animals by fitting the test-day (TD) specific effects. Our objective was to implement a random regression model for the evaluation of dairy production traits in French goats. RESULTS: The data consisted of milk TD records from 30,186 and 32,256 first lactations of Saanen and Alpine goats. Milk yield, fat yield, protein yield, fat content and protein content were considered. Splines were used to model the environmental factors. The genetic and permanent environmental effects were modeled by the same Legendre polynomials. The goodness-of-fit and the genetic parameters derived from functions of the polynomials of orders 0 to 4 were tested. Results were also compared to those from a lactation model with total milk yield calculated over 250 days and to those of a multiple-trait model that considers performance in six periods throughout lactation as different traits. Genetic parameters were consistent between models. Models with fourth-order Legendre polynomials led to the best fit of the data. In order to reduce complexity, computing time, and interpretation, a rank reduction of the variance covariance matrix was performed using eigenvalue decomposition. With a reduction to rank 2, the first two principal components correctly summarized the genetic variability of milk yield level and persistency, with a correlation close to 0 between them. CONCLUSIONS: A random regression model was implemented in France to evaluate and select goats for yield traits and persistency, which are independent i.e. no genetic correlation between them, in first lactation.


Assuntos
Cabras/genética , Lactação/genética , Modelos Genéticos , Modelos Estatísticos , Animais , Indústria de Laticínios , Feminino , Cabras/fisiologia , Masculino , Leite , Análise de Regressão
7.
Vet Immunol Immunopathol ; 214: 109890, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31378218

RESUMO

Bovine mastitis is a significant cause of economic losses in the dairy industry. Staphylococcus aureus is one of the most common contagious mastitis pathogens, whereas Staphylococcus chromogenes increasingly became a significant cause of subclinical mastitis in dairy cows. Current mastitis control measures are not effective on all mastitis pathogens. There is no effective vaccine to control Staphylococcal mastitis in dairy cows. The objective of this study was to evaluate the immune responses and protection in dairy cows vaccinated with S. aureus surface proteins (SASP) or S. chromogenes surface proteins (SCSP). We divided eighteen Holstein dairy cows randomly into three groups of 6 animals each. We vaccinated group 1 and 2 animals with SASP and SCSP with Emulsigen-D adjuvant, respectively. We injected control (group 3) animals with PBS (pH 7.2) in Emulsigen®-D. We vaccinated animals three times at 28 and 14 days before drying off, and at dry off. Two weeks after the third vaccination, we challenged each animal by dipping all teats in S. aureus culture suspension once daily for 14 consecutive days. We evaluated milk or mammary secretion and serum antibody titers during vaccination and challenge periods. We evaluated milk samples for the number of bacteria shedding and somatic cell counts (SCC). Out of six cows vaccinated with SASP, one cow was removed from the study due to injury, two were infected clinically, another two were infected subclinically, and the remaining cow was not infected. No SCSP vaccinated cows developed clinical or subclinical mastitis. Out of six control cows, two developed clinical mastitis whereas four were infected subclinically. The SCSP vaccine cross-protected against S. aureus mastitis and reduced number of S. aureus shedding in milk. We concluded that the SCSP is a promising vaccine to control Staphylococcal mastitis in dairy cows.


Assuntos
Mastite Bovina/prevenção & controle , Proteínas de Membrana/imunologia , Infecções Estafilocócicas/veterinária , Vacinas Antiestafilocócicas/imunologia , Staphylococcus aureus/imunologia , Animais , Derrame de Bactérias , Bovinos , Contagem de Células , Indústria de Laticínios , Feminino , Proteínas de Membrana/administração & dosagem , Leite/microbiologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/prevenção & controle , Vacinação
8.
Acta Vet Scand ; 61(1): 30, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300066

RESUMO

BACKGROUND: Veterinary remedies are intended to support animals in their recovery from diseases. Treatment outcome depends not only on the general effectiveness of the remedies themselves, but also on other prerequisites. This is true for antibiotics, but even more so for treatments with homeopathic products which are characterised by their individualised approach. While the effectiveness of homeopathy has been addressed in various clinical control trials, the practical conditions under which homeopathic products are used on dairy farms have not yet been investigated. This study provides an initial insight into the existing prerequisites on dairy farms for the use of homeopathy (i.e. the consideration of homeopathic principles) and on homeopathic treatment procedures (including anamnesis, clinical examination, diagnosis, selection of a remedy, follow-up checks, and documentation) on 64 dairy farms in France, Germany and Spain. The use of homeopathy was assessed via a standardised questionnaire during face-to-face interviews. RESULTS: The study revealed that homeopathic treatment procedures were applied very heterogeneously and differed considerably between farms and countries. Farmers also use human products without veterinary prescription as well as other prohibited substances. CONCLUSIONS: The subjective treatment approach using the farmers' own criteria, together with their neglecting to check the outcome of the treatment and the lack of appropriate documentation is presumed to substantially reduce the potential for a successful recovery of the animals from diseases. There is, thus, a need to verify the effectiveness of homeopathic treatments in farm practices based on a lege artis treatment procedure and homeopathic principles which can be achieved by the regular monitoring of treatment outcomes and the prevailing rate of the disease at herd level. Furthermore, there is a potential risk to food safety due to the use of non-veterinary drugs without veterinary prescription and the use of other prohibited substances.


Assuntos
Doenças dos Bovinos/terapia , Indústria de Laticínios/estatística & dados numéricos , Homeopatia/veterinária , Animais , Bovinos , Feminino , França , Alemanha , Homeopatia/estatística & dados numéricos , Espanha , Inquéritos e Questionários
9.
Prev Vet Med ; 169: 104692, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31311636

RESUMO

Dairy cattle experience metabolic stress during the transition from late gestation to early lactation resulting in higher risk for several economically important diseases (e.g. mastitis, metritis, and ketosis). Metabolic stress is described as a physiological state composed of 3 processes: nutrient metabolism, oxidative stress, and inflammation. Current strategies for monitoring transition cow nutrient metabolism include assessment of plasma non-esterified fatty acids and beta-hydroxybutyrate concentrations around the time of calving. Although this method is effective at identifying cows with higher disease risk, there is often not enough time to implement intervention strategies to prevent health disorders from occurring around the time of calving. Previously, we published predictive models for early lactation diseases at the individual cow level at dry-off. However, it is unknown if predictive probabilities from individual-level models can be aggregated to the cohort level to predict cohort-level incidence. Therefore, our objective was to test different data aggregation methods using previously published models that represented the 3 components of metabolic stress (nutrient metabolism, oxidative stress, and inflammation). We included 277 cows from five Michigan dairy herds for this prospective cohort study. On each farm, two to four calving cohorts were formed, totaling 18 cohorts. We measured biomarker data at dry-off and followed the cows until 30 days post-parturition for cohort disease incidence, which was defined as the number of cows: 1) having one or more clinical transition disease outcome, and/or 2) having an adverse health event (abortion or death of calf or cow) within each cohort. We tested three different aggregation methods that we refer to as the p-central, p-dispersion, and p-count methods. For the p-central method, we calculated the averaged predicted probability within each cohort. For the p-dispersion method, we calculated the standard deviation of the predicted probabilities within a cohort. For the p-count method, we counted the number of cows above a specified threshold of predicted probability within each cohort. We built four sets of models: one for each aggregation method and one that included all three aggregation methods (p-combined method). We found that the p-dispersion method was the only method that produced viable predictive models. However, these models tended to overestimate incidence in cohorts with low observed counts and underestimate risk in cohorts with high observed counts.


Assuntos
Doenças dos Bovinos/epidemiologia , Análise Multivariada , Estresse Fisiológico , Aborto Animal/epidemiologia , Animais , Biomarcadores , Bovinos , Doenças dos Bovinos/sangue , Estudos de Coortes , Indústria de Laticínios , Feminino , Incidência , Mastite Bovina/epidemiologia , Michigan/epidemiologia , Período Pós-Parto , Fatores de Risco
10.
Prev Vet Med ; 169: 104701, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31311637

RESUMO

During the transition from late gestation to early lactation, dairy cattle are at increased risk for disease. Herd-level monitoring for disease risk involves evaluating multiple factors, including food intake, cow density, and biomarkers of nutrient metabolism. Biomarkers that are measured include non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB), which are usually measured in a subset of the herd (i.e. cohort). If a certain proportion of cows in the cohort are above a specific threshold for a biomarker, the cohort is considered at high risk of disease. Few previous studies have investigated other methods to aggregate individual cow-level data to the cohort level. We designed a proof-of-concept study to determine if biomarker aggregation methods may be useful to predict cohort incidence of adverse health events including 1) clinical diseases: mastitis, metritis, retained placenta, ketosis, lameness, pneumonia, milk fever, displaced abomasum, 2) and abortion or death of the calf or the cow. The study design was a prospective cohort study that used cows (N = 277) from five Michigan commercial dairy herds. Multiple cohorts of cows (two to four cohorts per farm, 18 total) were enrolled that shared the same dry-off date. We tested three different methods (central, dispersion, and count) to aggregate individual cow data (i.e. biomarkers and covariates) measured at dry-off. The central method consisted of calculating the average value of each variable within a cohort, and the dispersion method involved taking the standard deviation or mean absolute deviation about the median of each variable within a cohort. The count method consisting of counting the number of cows above a specific threshold for each variable within a cohort. We used best subsets selection to select a bouquet of candidate models for each aggregation method and averaged the predictions over the model set. We built 4 sets of Poisson regression models: one for each aggregation method and a combined model that included all three methods. We evaluated the models based on goodness-of-fit, model calibration using scoring rules, and comparison of observed versus predicted counts. The central and the combined method produced models that had good fit and model calibration. These results indicate that it may be possible to use aggregate measures to predict cohort disease incidence as early as dry-off. The next step is to test biomarker aggregation methods in studies with larger sample sizes.


Assuntos
Biomarcadores/sangue , Doenças dos Bovinos/sangue , Doenças dos Bovinos/epidemiologia , Ácido 3-Hidroxibutírico/sangue , Animais , Bovinos , Doenças dos Bovinos/diagnóstico , Estudos de Coortes , Indústria de Laticínios , Ácidos Graxos não Esterificados/sangue , Feminino , Incidência , Mastite Bovina/diagnóstico , Mastite Bovina/epidemiologia , Michigan/epidemiologia , Estresse Oxidativo , Placenta Retida , Distribuição de Poisson , Período Pós-Parto , Gravidez , Estudos Prospectivos , Fatores de Risco , Sensibilidade e Especificidade
11.
Prev Vet Med ; 169: 104694, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31311645

RESUMO

In dairy cattle, reproductive diseases and infertility are some of the most important reasons for culling, where postpartum negative energy balance (NEB) reduces reproductive performance. This single cohort observational study reports the association between eating time and the interval between calving and first service in 2036 dairy cows on 17 commercial farms in The Netherlands. Cows were equipped with a commercially available neck sensor (Nedap, Groenlo, The Netherlands), that measured the time cows spent eating, from 28 days (d) before until 28 d after parturition. Primiparous cows spent a mean of +45 minutes (min) eating time per day ante partum and +15 min eating time post partum more than multiparous cows. A Cox proportional hazard model was used to analyze eating time variables in relation to the interval between calving and first service. From 4 weeks before until 4 weeks after calving eating time variables per week were used. Weeks -4, -3 + 3 and +4 were used as weeks with stable eating time patterns and therefore the mean eating time per week and the standard deviation of the mean eating time per week were used. Weeks -2, -1, +1 and +2 were addressed as periods with unstable eating patterns and therefore the slope in eating time per week and the residual variance of the slope per week were modeled. Significant results were the mean eating time in week -4 and +3 where in both weeks higher eating time lead to a higher hazard for first service. Difference between primiparous and multiparous cows were also significant with a higher hazard for first service for primiparous cows. Week 4 post partum presented a significant difference between eating time of primiparous cows and multiparous cows. These results display how eating time variables in the transition period could be related to the interval between calving and first service, and that there is a relation between mean eating time in week -4, +3, +4 and the interval between calving and first insemination.


Assuntos
Ingestão de Alimentos , Comportamento Alimentar , Paridade , Parto , Animais , Bovinos , Estudos de Coortes , Indústria de Laticínios , Ingestão de Alimentos/fisiologia , Comportamento Alimentar/fisiologia , Feminino , Países Baixos , Paridade/fisiologia , Parto/fisiologia , Período Pós-Parto , Gravidez , Modelos de Riscos Proporcionais , Tempo
12.
Vet Microbiol ; 235: 71-79, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282381

RESUMO

Streptococcus agalactiae (Group B streptococcus, GBS) is a commensal of the human intestinal tract and vagina and is also an opportunistic pathogen causing serious, potentially lethal, infections preferentially in newborns and in the elderly. In cattle, it is considered an udder-specific pathogen and a common cause of mastitis. Here we investigated the host specificity of GBS by examining their colonization at various anatomical sites in both cattle and humans, as well as the possible cross-species transmission in closed barn environments. We collected more than 800 swab samples from dairy cows and herdspersons at eight dairy farms in Denmark. GBS was isolated from 12% of the samples. The GBS strains (N = 105) were characterized by biochemical test, serology, and Pulsed-Field Gel Electrophoresis (PFGE). Based on the PFGE patterns, 25 strains were selected for whole genome sequencing followed by phylogenetic analyses. The genomes were compared to each other and to a collection of publicly available GBS genomes. The study revealed that GBS clones were shared by cows and herdspersons. In phylogenetic analyses, these shared clones clustered with GBS strains from persons with no relation to farming. Horizontal cross-species transmission of the contagion in both directions was found to be highly likely within the same environment; thus, some cases of bovine mastitis are probably antrophonotic.


Assuntos
Bovinos/microbiologia , Fazendeiros , Especificidade de Hospedeiro , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/genética , Animais , Indústria de Laticínios , Dinamarca , Reservatórios de Doenças/microbiologia , Feminino , Humanos , Masculino , Mastite Bovina/microbiologia , Leite/microbiologia , Faringe/microbiologia , Filogenia , Reto/microbiologia , Infecções Estreptocócicas/transmissão , Streptococcus agalactiae/isolamento & purificação , Vagina/microbiologia
13.
Sci Total Environ ; 691: 960-968, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31326818

RESUMO

Facilitating anaerobic degradation of long-chain fatty acids (LCFA) is key for tapping the high methane production potential of the fats, oil and grease (FOG) content of dairy wastewaters. In this study, the feasibility of using high-rate granular sludge reactors for the treatment of mixed LCFA-containing synthetic dairy wastewater (SDW) was assessed at 20 °C. The effects of the LCFA concentration (33-45% of COD) and organic loading rates (2-3 gCOD/L·d) were determined using three parallel expanded granular sludge bed reactors. For the first time, long term anaerobic treatment of LCFA-containing feed at 20 °C was shown to be feasible and was linked to the microbial community dynamics in high-rate reactors. During a two-month operation, a soluble COD removal of 84-91% and COD to methane conversion of 44-51% was obtained. However, granular sludge flotation and washout occurred after two months in all reactors without volatile fatty acids (VFA) accumulation, emphasizing the need for sludge retention for long-term granular sludge reactor operation with LCFA-containing feed at low ambient temperatures. The temporal shifts in microbial community structure were studied in the high-rate treatment of SDW, and the process disturbances (elevated LCFA loading, LCFA accumulation, and batch operation) were found to decrease the microbial community diversity. The relative abundance of Methanosaeta increased with higher LCFA accumulation in the settled and flotation layer granules in the three reactors, therefore, acetoclastic methanogenesis was found to be crucial for the high-rate treatment of SDW at 20 °C. This study provides an initial understanding of the continuous anaerobic treatment of LCFA-containing industrial wastewaters at low ambient temperatures.


Assuntos
Indústria de Laticínios , Microbiota , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Anaerobiose
14.
Onderstepoort J Vet Res ; 86(1): e1-e9, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291733

RESUMO

South Africa is a large country of approximately 1.22 million km2, made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences. Of the different organisms isolated from milk samples of dairy cows, Staphylococcus aureus poses a challenge to maintain udder health and wholesome dairy products for human consumption. Antibiotic resistant bacteria are therefore a potential health hazard. The objective of this study was to investigate the seasonal and regional relationships of antibiotic resistance of S. aureus, of which little is known. This study was undertaken to evaluate a data set of 3410 S. aureus isolates, taken from milk samples with a somatic cell count of > 400 000 cells/mL from commercial dairy herds. These isolates were tested for antimicrobial susceptibility using the Kirby Bauer method for ampicillin, cloxacillin, penicillin G, clindamycin, oxy-tetracycline, cephalexin, cefuroxime and tylosin. The samples were from 830 dairy herds, out of the estimated 2000 commercial dairy herds in South Africa. All the antibiotics tested, except for cephalosporins, showed a predicted prevalence of resistance of above 50% in most provinces, which is a concern. The lowest prevalence of resistance to the majority of the categories of antibiotics tested was present in KwaZulu-Natal during spring. The cephalosporins had the lowest levels of prevalence of bacterial resistance in Gauteng during winter. Resistance patterns of S. aureus to the eight antibiotics varied in the different seasons and provinces, possibly because of different weather conditions, and the action and spectrum of antibiotics.


Assuntos
Antibacterianos/farmacologia , Indústria de Laticínios , Mastite Bovina/epidemiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Animais , Bovinos , Clima , Demografia , Farmacorresistência Bacteriana , Feminino , Mastite Bovina/microbiologia , Testes de Sensibilidade Microbiana/veterinária , Prevalência , África do Sul/epidemiologia , Infecções Estafilocócicas/epidemiologia
15.
Animal ; 13(S1): s86-s93, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31280744

RESUMO

Small ruminants not only differ on mammary gland anatomy, milk's properties and the amount of milk yielded comparable to those of dairy cattle, but also on the milking routine strategies and machine milking settings to maximize daily milk secretion. The udder compartment is proportionally larger in dairy sheep and goats, which requires modifications in the milking machine settings, milking procedures and allows the use of different milking strategies as they better tolerate extension of milking intervals. Depending on the breed, cisternal milk in goats varies from 70% to 90%, whereas in dairy sheep it varies from 50% to 78% of the total gland capacity. This explains why these species are commonly milked without pre-milking teat preparation, while in goats it is applied only in cases of high prevalence of intramammary infection in the herd. Recent French researchers observed that 40% of the goats presented an unbalanced udder as well as unbalanced morphology (21% to 30%) and functional milk flow (around 10% to 20% more) which could induce overmilking. In dairy sheep, selection for higher milk production increases teat angle insertion. Thus, to increase machine milk fraction, it is recommended to use either the 'Sagi hook' as an alternative for lifting up the 'pendulous' udder during milking or to perform machine stripping. There are three cluster removal strategies for small ruminants: manual, timed and milk flow driven automatic cluster removal (ACR). Automatic cluster removal reduces overmilking, improves teat condition, enables labour saving and provides a consistent milking routine in small ruminants. There are three to five main milk flow profiles in ewes and goats, which result in curves with one or two peaks (or plateau) and different patterns of the milk flow decreasing phase due to the degree of mammary gland imbalance and teat characteristics. When taking into account our current knowledge, ACR recommended take-off settings for goats are: 200 g/min+10 s delay time (DT) for a long decreasing phase or two plateau curves and 500 g/min+5 s DT for a short decreasing phase and one plateau curve. The ACR take-off settings for ewes are: 150 g/min +10 s DT for long decreasing phase and 200 g /min+5 s DT for a short decreasing phase. This review is intended to be useful for scientists and producers seeking basic knowledge of milking routines and cluster detachment settings for parlour performance and milk quality.


Assuntos
Indústria de Laticínios/métodos , Cabras/fisiologia , Lactação , Leite/metabolismo , Ovinos/fisiologia , Animais , Feminino , Glândulas Mamárias Animais/fisiologia , Leite/normas , Ruminantes
16.
Animal ; 13(S1): s94-s99, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31280747

RESUMO

Because of technical limitations, an impact of machine milking on the teat tissue cannot be avoided. The continuance of this impact during and after milking depends on a variety of factors related to the physiological regulation of milk ejection, as well as the different production systems and milking machine settings. Milking machine settings aim to achieve a high milking performance, that is, short machine-on time at a maximum of milk harvest. However, a high milking performance level is often related to an impact on the teat tissue caused by vacuum or liner compression that can lead to pathological dimensions of congestion of the tissue or hyperkeratosis as a long-term effect. Toward the end of milking a decrease of milk flow rate causes a raise of mouthpiece and teat end vacuum levels and hence an increase of the impact on the teat tissue and the risk of tissue damage. The mechanical stress by the milking machine activates a cascade of cellular mechanisms that lead to an excessive keratin growth and thickening of the keratin layer. Consequently, a complete closure of the teat canal is disabled and the risk of bacterial invasion and intramammary infection increases. Another consequence of high vacuum impact is fluid accumulation and congestion in the tissue of teat tip and teat basis because of an obstruction in venous return. The present review paper provides an overview of the available scientific information to describe the interaction between different levels and types of system vacuum, mouthpiece chamber vacuum, teat end (claw) vacuum, liner pressure, and the risk of short-term and long-term impacts on the teat tissue.


Assuntos
Bovinos/fisiologia , Indústria de Laticínios/métodos , Lactação/fisiologia , Glândulas Mamárias Animais/fisiologia , Leite/metabolismo , Animais , Indústria de Laticínios/instrumentação , Feminino , Fatores de Tempo , Vácuo
17.
Animal ; 13(S1): s52-s64, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31280749

RESUMO

The mammary tissue is characterized by its capacity to adapt in response to a wide variety of changing conditions. This adaptation capacity is referred to as the plasticity of mammary tissue. In dairy ruminants, lactation is challenged by modifications that can either be induced on purpose, such as by modifying management practices, or occur involuntarily, when adverse environmental constraints arise. These modifications can elicit both immediate changes in milk yield and composition and carryover effects that persist after the end of the challenge. This review focuses on the current knowledge concerning the cellular mechanisms underlying mammary tissue plasticity. The main mechanisms contributing to this phenomenon are changes in the activity and number of mammary epithelial cells (MECs). Changes in the number of these cells result from variations in the rates of cell proliferation and death as well as changes in the rate MEC exfoliation. The number of MECs also depends on the number of resident adult mammary stem cells and their progenitors, which can regenerate the pools of the various mammary cells. Several challenges, including changes in milking frequency, changes in level of feed supply and hormonal manipulations, have been shown to modulate milk yield together with changes in mammary cell activity, turnover and exfoliation. Epigenetic changes may be an additional mechanism of adaptation. Indeed, changes in DNA methylation and reductions in milk yield have been observed during once-daily milking and during mastitis in dairy cows and may affect cell activity persistently. In contrast to what has been assumed for a long time, no carryover effect on milk yield were observed after feed supply challenges in dairy cows and modification of milking frequency in dairy goats, even though the number of mammary cells was affected. In addition, mammary tissue plasticity has been shown to be influenced by the stage of lactation, health status and genetic factors. In conclusion, the cellular mechanisms underlying mammary tissue plasticity are diverse, and the mammary tissue either does or does not show elastic properties (with no permanent deformation), in response to environmental changes.


Assuntos
Lactação/fisiologia , Glândulas Mamárias Animais/fisiologia , Leite/metabolismo , Ruminantes/fisiologia , Animais , Contagem de Células/veterinária , Proliferação de Células , Indústria de Laticínios , Células Epiteliais/fisiologia , Feminino
18.
Animal ; 13(S1): s65-s74, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31280750

RESUMO

This paper reviews the effects of extended lactation (EXT) as a strategy in dairy cattle on milk production and persistency, reproduction, milk quality, lifetime performance of the cow and finally the economic effects on herd and farm levels as well as the impact on emission of greenhouse gas at product level. Primiparous cows are able to produce equal or more milk per feeding day during EXT compared with a standard 305-d lactation, whereas results for multiparous cows are inconsistent. Cows managed for EXT can achieve a higher lifetime production while delivering milk with unchanged or improved quality properties. Delaying insemination enhances mounting behaviour and allows insemination after the cow's energy balance has become positive. However, in most cases EXT has no effect or a non-significant positive effect on reproduction. The EXT strategy sets off a cascade of effects at herd and farm level. Thus, the EXT strategy leads to fewer calvings and thereby expected fewer diseases, fewer replacement heifers and fewer dry days per cow per year. The optimal lifetime scenario for milk production was modelled to be an EXT of 16 months for first parity cows followed by an EXT of 10 months for later lactations. Modelling studies of herd dynamics indicate a positive effect of EXT on lifetime efficiency (milk per dry matter intake), mainly originating from benefits of EXT on daily milk yield in primiparous cows and the reduced number of replacement heifers. Consequently, EXT also leads to reduced total meat production at herd level. For the farmer, EXT can give the same economic return as a traditional lactation period. At farm level, EXT can contribute to a reduction in the environmental impact of dairy production, mainly as a consequence of the reduced production of beef. A wider dissemination of the EXT concept will be supported by methods to predict which cows may be most suitable for EXT, and clarification of how milking frequency and feeding strategy through the lactation can be organised to support milk yield and an appropriate body condition at the next calving.


Assuntos
Bovinos/fisiologia , Lactação/fisiologia , Leite/metabolismo , Reprodução , Animais , Indústria de Laticínios/economia , Metabolismo Energético , Feminino , Gases de Efeito Estufa , Leite/normas , Paridade , Gravidez
19.
BMC Vet Res ; 15(1): 266, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31358004

RESUMO

BACKGROUND: Johne's disease is a major production limiting disease of dairy cows caused by infection with Mycobacterium avium subsp. paratuberculosis in calf-hood. The disease is chronic, progressive, contagious and widespread with no treatment and no cure. Economic losses arise from decreased productivity through reduced growth, milk yield, fertility and also capital losses due to premature culling or death. Control chiefly centers upon removing those animals which actively shed bacteria and protecting calves from infection. A prolonged pre-clinical shedding phase, lack of test sensitivity, organism persistence and abundance in the environment as well as management systems that expose susceptible calves to infection make control challenging, particularly in pastoral, seasonal dairy systems. Combining a novel testing strategy to remove infected cows along with limited measures to protect vulnerable calves at pasture, this study reports the successful reduction over a four-year period of seroprevalence of cows testing positive for MAP infection in a New Zealand pastoral dairy herd. RESULTS: For all age groups considered the apparent seroprevalence of cows testing positive decreased from 297 / 1,122 (26%) in 2013-2014, to 24 / 1,030 (2.3%) in 2016-2017. Over the same period, the apparent seroprevalence in primiparous cows decreased from 39 / 260 (15%) to 7 / 275 (2.5%) and in multiparous cows from 258 / 862 (29.9%) to 17 / 755 (2.3%). The reported proportion of calved cows culled annually from suspected clinical Johne's disease fell from 55 / 1,201 (5%) in the year preceding the control program to 5 / 1,283 (0.4%) in the final year of the study. CONCLUSIONS: On this farm, reduction in the prevalence of infection was achieved by reducing the infectious pressure through targeted culling of heavily shedding animals together with limited measures to protect calves at pasture from exposure to Mycobacterium avium subsp. paratuberculosis. Whilst greater protection of young animals through separation from infected cows and their colostrum and milk would have reduced the risk of neonatal infection, this study demonstrates, in this case, that these management measures while prudent were not essential for effective reduction in the prevalence of MAP infection.


Assuntos
Doenças dos Bovinos/epidemiologia , Mycobacterium avium subsp. paratuberculosis/fisiologia , Paratuberculose/epidemiologia , Animais , Bovinos , Doenças dos Bovinos/prevenção & controle , Indústria de Laticínios , Nova Zelândia/epidemiologia , Paratuberculose/prevenção & controle , Estudos Soroepidemiológicos
20.
Schweiz Arch Tierheilkd ; 161(7): 445-452, 2019 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-31298213

RESUMO

INTRODUCTION: Overbagged udders are commonly seen at dairy cow shows in Switzerland and abroad due to prolonged milking intervals. In recent years various studies documented the negative effects of prolonged milking intervals and examined the objectivity of an ultrasound-based assessment scheme for determining udder filling. In addition, risk factors were calculated which lead to udder edema outside the puerperal phase. For example, the effects of a sudden increased 24-hour milking interval were altered behavior (reduced feeding time, increased rumination time) and a significantly increased cell count in experimental cows. Edema formation was observed sonographically in the subcutaneous udder tissue at the sites of predilection known from previous studies. No evidence of edema was observed in cows milked at 12 hour intervals. Based on these results, a new scoring system was defined using ultrasound images of show cows (grade 0 = no edema, grade 1 = slight, grade 2 = moderate, grade 3 = severe edema). Results documented that experienced clinicians were able to score ultrasound images reliable (interobserver reliability κ = 0.815, three different clinicians; intraobserver reliability κ = 0.90 and κ = 0.85, two clinicians) and little variability existed between the clinicians. A prolonged milking interval was identified as the main risk factor. Modified Swiss Dairy Show Regulations were implemented by January 1st, 2018 and ultrasonographic examinations proofed to be reliable in practice. Since January 1st, 2019 visual scoring of the udder filling is evaluated as part of a pre-show inspection. The sonographic evaluation can be used as a reliable diagnostic addition.


Assuntos
Indústria de Laticínios/métodos , Glândulas Mamárias Animais/diagnóstico por imagem , Animais , Bovinos , Indústria de Laticínios/instrumentação , Feminino , Lactação , Suíça , Fatores de Tempo
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