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1.
Animals (Basel) ; 9(12)2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31805754

RESUMO

The objective of our study was to identify genomic regions associated with varying concentrations of non-esterified fatty acid (NEFA), ß-hydroxybutyrate (BHB), and the development of hyperketonemia (HYK) in longitudinally sampled Holstein dairy cows. Our study population consisted of 147 multiparous cows intensively characterized by serial NEFA and BHB concentrations. To identify individuals with contrasting combinations in longitudinal BHB and NEFA concentrations, phenotypes were established using incremental area under the curve (AUC) and categorized as follows: Group (1) high NEFA and high BHB, group (2) low NEFA and high BHB), group (3) low NEFA and low BHB, and group (4) high NEFA and low BHB. Cows were genotyped on the Illumina Bovine High-density (777K) beadchip. Genome-wide association studies using mixed linear models with the least-related animals were performed to establish a genetic association with HYK, BHB-AUC, NEFA-AUC, and the comparisons of the 4 AUC phenotypic groups using Golden Helix software. Nine single-nucleotide polymorphisms were associated with high longitudinal concentrations of BHB and further investigated. Five candidate genes related to energy metabolism and homeostasis were identified. These results provide biological insight and help identify susceptible animals thus improving genetic selection criteria thereby decreasing the incidence of HYK.

2.
PLoS One ; 14(9): e0222442, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31509595

RESUMO

Understanding farmers' behavior, motivations, and perceptions toward antimicrobial use can influence how veterinarians translate research into practice and guide effective ways of implementing protocols. A multidisciplinary team investigated behavioral tendencies of New York dairy farmers toward antimicrobial use by administering a survey modeled with the reasoned action approach. This approach is a framework from social psychology containing the constructs attitude, perceived norms, and perceived behavioral control, and is used in combination with structural equation modeling to determine what drives intentions. Multiple indicators and multiple causes (MIMIC) models were then used to determine the effects of beliefs on their underlying constructs. The objective of the study was to provide direct and indirect measures of the constructs using survey data to determine importance of and associations with intention to use antimicrobials prudently. The structural equation model indicated that perceived behavioral control explained intention. Thus, farmers who feel capable of prudent use expressed positive intentions. Attitude and perception of others also had influence to a lesser extent. MIMIC models showed that the most important attributes of instrumental attitude were increasing profitability, decreasing risk of residues, and increasing herd health. Contributing attributes of affective attitude were job satisfaction, decreasing resistance, and increasing milk production. For perceived norms, the attributes were opinions/approval of family and peers, veterinarians, and milk processors. Finally, for perceived behavioral control, attributes focused on saving money on labor and treatment, ability to fit into the daily routine, and effectiveness with veterinary guidance. In conclusion, the best approach for adoption of practices might be presentation of examples of successful strategies by other producers, particularly in peer groups. In addition, veterinarians should provide the tools and guidance needed to produce economic gain, reduction of risks associated with residues and resistance, and positive experiences when using the tactics.

3.
J Dairy Sci ; 102(4): 3474-3479, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30738680

RESUMO

Our objectives were to evaluate the clinical efficacy of oral and intranasal administration of a commercial modified-live Salmonella Dublin vaccine in dairy calves and to determine the serologic response associated with these extralabel routes of administration. We conducted a randomized field trial with calves from a New York dairy farm following an outbreak of Salmonella Dublin. A total of 399 Holstein calves were allocated by pen to 3 treatment groups: oral vaccination, intranasal vaccination, and an unvaccinated control group. Administration of the vaccine through oral and intranasal routes did not have a significant effect on pneumonia incidence risk or weight gain; however, calves vaccinated orally and intranasally had lower mortality risk as compared with control calves. Among calves tested using a Salmonella Dublin ELISA, vaccination did not induce an increase in antibody production relative to control calves, indicating that oral and intranasal administration will not hinder diagnosis based on this assay.


Assuntos
Doenças dos Bovinos/prevenção & controle , Salmonelose Animal/prevenção & controle , Vacinas contra Salmonella/imunologia , Salmonella enterica , Administração Intranasal , Administração Oral , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Ensaio de Imunoadsorção Enzimática , New York , Distribuição Aleatória , Vacinas contra Salmonella/administração & dosagem , Resultado do Tratamento , Vacinação , Vacinas Atenuadas
4.
BMC Vet Res ; 15(1): 58, 2019 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-30755196

RESUMO

BACKGROUND: Premilking udder preparation is essential for harvesting high-quality milk as gently, completely, and quickly as possible. The associations between characteristics such as teat-end shape and premilking stimulation on milking characteristics and machine milking-induced changes to the teat tissue condition have not been rigorously investigated. The primary objective was to investigate the interactive effects of manual premilking stimulation (i.e., preparation lag time) and teat-end shape on total milk yield, two-minute milk yield, milking unit-on time, and time in low milk flow rate. Our secondary objective was to study the association of manual premilking stimulation and changes to the teat tissue condition after machine milking (i.e., short-term changes). In a longitudinal prospective cohort study, 384 milking observations from 129 cows were analysed. Holstein cows were housed in sand-bedded free-stall pens, fed a total mixed ration, and milked 3 times a day. Cows were classified by teat-end shape into 1 of 3 categories: pointed, flat, or round. Individual cow milking characteristics were recorded with electronic on-farm milk meters. The duration of manual stimulation, preparation lag time, and presence of short-term changes were documented for each milking observation. General linear mixed models were used to study the interactive effects of preparation lag time and teat-end shape on milking characteristics. RESULTS: There was an interaction between preparation lag time and teat-end shape for two-minute milk yield and time in low milk flow rate. The preparation lag time effect was modified by teat-end shape, while no interaction was observed for total milk yield or milking unit-on time. A generalized linear mixed model revealed that preparation lag time was associated with short-term changes in teat tissue condition, where the odds of short-term changes decreased as preparation lag time increased. CONCLUSIONS: In summary, cows with different teat-end shapes may require different premilking stimulation regimens. Increasing preparation lag time benefits teat tissue condition during machine milking. Further research is warranted to optimize individual premilking stimulation in dairy cows.


Assuntos
Bovinos/fisiologia , Indústria de Laticínios/métodos , Lactação , Glândulas Mamárias Animais/fisiologia , Animais , Bovinos/anatomia & histologia , Feminino , Lactação/fisiologia , Estudos Longitudinais , Glândulas Mamárias Animais/anatomia & histologia , Estudos Prospectivos
5.
Prev Vet Med ; 161: 9-18, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30466663

RESUMO

The objectives of this study were to characterize the pathogen frequency and severity of clinical mastitis (CM) in 20 dairy herds of southeastern Brazil; and to determine the incidence rate of clinical mastitis (IRCM; overall and based on specific-pathogen groups) based on quarter time at risk and its association with risk factors at the herd-level. Data were recorded in each herd for a period of 8 to 15 months. The association between herd-level risk factors and IRCM were determined by two groups of mixed regression models: one based on the overall IRCM, and five based on the following specific-pathogen groups: contagious, other Gram-positive, Gram-negative, other, and negative culture. The following herd-level risk factors were evaluated: herd size, housing system, average daily milk yield per cow, bulk milk somatic cell count (BMSCC), and bulk milk total bacterial count (BMTBC). A total of 5957 quarter-cases of CM were recorded from 2637 cows, but only 4212 cases had milk samples collected for culture. The most frequently isolated pathogens were Escherichia coli (6.6% of total cultures), Streptococcus uberis (6.1%), and Streptococcus agalactiae (5.9%). The majority of CM cases were mild (60.3%), while 34.1% were moderate and 5.6% severe. The frequency of severe CM cases was lower for those with a Gram-positive result (4.6%) compared to a Gram-negative result (11.4%). Overall, monthly mean IRCM was 9.7 cases per 10,000 quarter-days at risk (QDAR). Herds with a geometric mean BMSCC ≥ 601 × 103 cell/mL had higher overall IRCM (16/10,000 QDAR) than those with BMSCC ≤ 600 × 103 cell/mL (≤7.7/10,000 QDAR). When the specific-pathogen groups were evaluated, for contagious pathogens, variables housing (free-stalls or compost-bedded pack barns), BMSCC (≥601 × 103 cells/mL), and average daily milk yield per cow (21 and 25 Kg/d) presented the highest IRCM. Furthermore, in Gram-negative group, herds with BMTBC ≥ 31 × 103 cfu/mL had higher IRCM compared with herds with BMTBC ≤ 30 × 103 cfu/mL. Although environmental pathogens were the most common cause of CM in this study, contagious pathogens (e.g., Strep. agalactiae and Staph. aureus) are still a concern in dairy herds of Brazil. Additionally, as there were some herd-level risk factors associated with the IRCM, there may be opportunity for management strategies aiming to improve the control of CM in dairy herds.


Assuntos
Infecções por Bactérias Gram-Negativas/veterinária , Infecções por Bactérias Gram-Positivas/veterinária , Mastite Bovina/epidemiologia , Mastite Bovina/microbiologia , Criação de Animais Domésticos/métodos , Animais , Brasil/epidemiologia , Bovinos , Indústria de Laticínios , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Feminino , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Positivas/epidemiologia , Incidência , Lactação , Leite , Estudos Prospectivos , Análise de Regressão , Fatores de Risco , Estações do Ano , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/veterinária , Streptococcus/isolamento & purificação
6.
Sci Rep ; 8(1): 5378, 2018 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-29599438

RESUMO

Treatment of bovine mastitis with intramammary antibiotics is common, yet several concerns exist including failed efficacy for individual hosts or pathogens and the inability of approved drugs to revert mastitis-induced tissue damage to healthy tissue capable of returning to full milk production. These issues, in addition to aspects of public health such as accidental antibiotic residues in saleable milk and the potential for antimicrobial resistance, support the need to find alternative therapies for this costly disease. This study shows that the secretome, or collective factors, produced by mammosphere-derived cells (MDC) promotes angiogenesis, epithelial cell migration, and contains proteins associated with immunity and defense; all of which are necessary for healing damaged mammary gland tissue. Furthermore, we found that the MDC secretome remains effective after freezing and thawing, enhancing its therapeutic potential. Our results provide a foundation for further characterization of the individual secreted factors and the rationale for using the MDC secretome as a complementary treatment for bovine mastitis.


Assuntos
Células Epiteliais/metabolismo , Neovascularização Fisiológica , Angiopoietina-1/genética , Angiopoietina-1/metabolismo , Animais , Toxinas Bacterianas/farmacologia , Bovinos , Movimento Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Feminino , Lactoferrina/análise , Lactoferrina/metabolismo , Lipopolissacarídeos/farmacologia , Glândulas Mamárias Animais/citologia , Espectrometria de Massas , Mastite Bovina/metabolismo , Mastite Bovina/patologia , Leite/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
7.
Prev Vet Med ; 120(3-4): 291-7, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25957974

RESUMO

The objective was to evaluate the association of peripartum concentrations of fecal cortisol metabolites (11,17-dioxoandrostane; 11,17-DOA), plasma cortisol and haptoglobin (Hp), as well as two markers of negative energy balance, non-esterified fatty acid (NEFA) and postpartum ß-hydroxybutyrate (BHBA), with milk yield and reproductive performance. Blood and fecal samples were collected weekly from 412 Holstein dairy cows from wk -3 through wk +1 relative to calving. Pregnancies by 150 days in milk (DIM) and projected 305-d mature equivalent (305ME) milk yield based on the 3rd Dairy Herd Improvement (DHI) test day (mean±SD; 102±17 DIM) were measured. Multivariable linear regression models were used to describe the associations of metabolites with 305ME milk yield. Semiparametric proportional hazards models were used to describe associations of the same metabolites with risk of conception by 150 DIM. Negative associations with milk yield were found for prepartum Hp in wk -2, -1, and +1 relative to calving (estimate±SE: 490±251, 564±259, and 464±136kg lower yield for every increase in Hp concentration by 1g/L, respectively) as well as with NEFA concentration in wk -2 (estimate±SE: 1465±541kg lower milk yield for an increase in NEFA concentration by 1mEq/L). Postpartum associations of NEFA with milk yield depended on parity; NEFA was associated with an increase in milk yield in primiparous animals only (estimate±SE: 1548±510kg increase for an increase in NEFA concentration by 1mEq/L). An increase in plasma cortisol concentration by 1µg/dL in wk +1 relative to calving was associated with an increase in milk yield (estimate±SE: 580±176kg). Prepartum 11,17-DOA was associated in all three prepartum sampling weeks with a reduced hazard ratio (HR) of conception (HR [95% CI]: 0.81 [0.67-0.97], 0.85 [0.72-0.99], and 0.85 [0.75-0.97] for every increase in concentration by 1mg/g fecal dry matter (DM) in wk -3, -2, and -1 relative to calving, respectively). Increased cortisol concentrations in wk -3 and -1 relative to calving were associated with decreased hazard of conception in primiparous animals only (HR [95% CI]: 0.54 [0.32-0.92] and 0.59 [0.35-0.99], respectively. Increases in postpartum metabolites Hp and BHBA had a negative association with hazard of conception (HR [95% CI]: 0.81 [0.70-0.97], 0.74 [0.56-0.98], respectively). Biomarkers of inflammation and stress around calving may be useful to assess opportunities for improved milk yield and reproduction.


Assuntos
Doenças dos Bovinos/imunologia , Doenças dos Bovinos/fisiopatologia , Metabolismo Energético , Lactação/fisiologia , Leite/metabolismo , Reprodução , Ácido 3-Hidroxibutírico , Androstanos/metabolismo , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Bovinos/fisiologia , Ácidos Graxos não Esterificados/metabolismo , Fezes/química , Feminino , Haptoglobinas/metabolismo , Hidrocortisona/sangue , Inflamação/imunologia , Inflamação/fisiopatologia , Lactação/sangue , New York , Período Periparto , Estresse Fisiológico
8.
Vet Med (Auckl) ; 6: 103-110, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-30155437

RESUMO

Obesity has been associated with an increased inflammatory response and insulin resistance due to adipose tissue-derived adipokines and increases in C-reactive protein (CRP). Dogs appear to be similar to other species with the exception of adiponectin, which might not be affected by obesity status. Serum long-chain polyunsaturated fatty acid concentrations have been positively and negatively associated with serum adipokines. The aim of the study was to examine the relationship between leptin, CRP, adiponectin, and insulin to body condition score (BCS) and to the long-chain omega-3 fatty acids in serum lipoproteins, including alpha-linolenic acid, eicosapentaenoic acid (EPA), docosapentanenoic acid (DPA), and docosahexaenoic acid (DHA) as a reflection of dietary omega-3 status in the Labrador Retriever. Seventy-seven Labrador Retrievers were evaluated for BCS, percent fasting serum lipoprotein fatty acid concentrations, as well as serum leptin, adiponectin, insulin, and CRP. A multivariable general linear regression model was constructed to examine the association between the dependent variables leptin, CRP, adiponectin, and insulin and the predictor variables of BCS, age, and sex, as well as concentrations of alpha-linolenic acid, EPA, DHA, and DPA. Adiponectin concentration was positively associated with age (P<0.0008), EPA (P=0.027) and negatively associated with DHA (P=0.008). Leptin concentration was positively associated with an increased DHA (P=0.009), BCS (P<0.0001), age (P=0.02), and decreased DPA (P=0.06). Insulin concentration was only associated with BCS (P<0.0001), and no meaningful associations were found for CRP. Longer chain omega-3 fatty acids may play a role in regulating adiponectin concentrations in dogs. However, because insulin concentrations were associated only with BCSs, further examination of the role of adiponectin in canine obesity is warranted. EPA and DPA may reduce the overall inflammatory state in dogs as these omega-3 fatty acids reflect increased adiponectin (increased EPA and decreased DHA) and decreased leptin (decreased DHA and increased DPA).

9.
Am J Trop Med Hyg ; 92(1): 45-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25371182

RESUMO

Cryptosporidium is an important diarrhea-associated pathogen, however the correlation between parasite burden and diarrhea severity remains unclear. We studied this relationship in 10 experimentally infected calves using immunofluorescence microscopy and real-time polymerase chain reaction (qPCR) (N = 124 fecal samples). The qPCR data were corrected for extraction/amplification efficiency and gene copy number to generate parasite counts. The qPCR and microscopic oocyst quantities exhibited significant correlation (R(2) = 0.33, P < 0.05), however qPCR had increased sensitivity. Upon comparison with diarrhea severity scores (from 0 to 3), a PCR-based count of ≥ 2.6 × 10(5) parasites or an immunofluorescence microscopy count of ≥ 4.5 × 10(4) oocysts were discriminatory predictors of moderate-to-severe diarrhea (versus no-to-mild diarrhea), with accuracies and predictive values of 72-82%. In summary, a quantitative approach for Cryptosporidium can refine predictive power for diarrhea and appears useful for distinguishing clinical cryptosporidiosis versus subclinical infection.


Assuntos
Doenças dos Bovinos/parasitologia , Criptosporidiose/parasitologia , Diarreia/veterinária , Microscopia de Fluorescência/métodos , Contagem de Ovos de Parasitas , Reação em Cadeia da Polimerase/métodos , Animais , Bovinos , Doenças dos Bovinos/fisiopatologia , Criptosporidiose/fisiopatologia , Diarreia/parasitologia , Diarreia/fisiopatologia , Oocistos
10.
J Zoo Wildl Med ; 45(2): 263-71, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25000686

RESUMO

It was observed previously that end-expired carbon dioxide (P(E)CO2) decreased when immobilized black rhinoceroses (Diceros bicornis) were moved from sternal to lateral recumbency. These experiments were designed to test whether greater alveolar ventilation or greater pulmonary dead space in lateral recumbency explains this postural difference in P(E)CO2. Twenty-one (9 male, 12 female; 15 [3.5-26] yr old) wild black rhinoceroses were immobilized with etorphine and azaperone and positioned in either sternal or lateral recumbency. All rhinoceroses were hypoxemic and had lactic and respiratory acidemia. The animals in lateral recumbency were more acidemic, had higher lactate, and lower arterial oxygen that those in sternal recumbency; however, arterial carbon dioxide was similar between groups. Both P(E)CO2 and mixed expired carbon dioxide pressure were lower in lateral than sternal recumbency. Although there was no difference in tidal volume or arterial carbon dioxide, both the breathing rate and minute ventilation were greater in lateral recumbency. The physiologic dead space ratio and dead space volume were approximately two times larger in lateral recumbency; hence, the decrease in P(E)CO2 in lateral recumbency can be attributed to increased dead space ventilation not increased alveolar ventilation. Positioning immobilized rhinoceroses in lateral recumbency does not confer any advantage over sternal in terms of ventilation, and the increase in minute ventilation in lateral recumbency can be considered an energetic waste. Although arterial oxygen was superior in sternal recumbency, further studies that measure oxygen delivery (e.g., to the muscles of locomotion) are warranted before advice regarding the optimal position for immobilized rhinoceroses can be given with confidence.


Assuntos
Imobilização , Perissodáctilos/fisiologia , Espaço Morto Respiratório/fisiologia , Animais , Animais Selvagens , Feminino , Masculino , Namíbia
11.
Prev Vet Med ; 113(1): 47-58, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-24416799

RESUMO

Disease caused by Brucella spp. represents the most common bacterial zoonotic infection worldwide. The distribution and public health impact of these infections in Nepal's mountain regions are poorly characterized. This cross sectional study assesses the burden of brucellosis on transhumant pastoralists and their yak in and around Shey Phoksundo National Park, Nepal. Objectives were to: (1) estimate individual animal prevalence of Brucella-seropositive yak, (2) identify herd- and individual-level risk factors associated with Brucella seropositivity in individual yak, and (3) identify herd-level risk factors associated with reported human brucellosis-like symptoms in a household. A case of household symptoms was defined as the reported occurrence within the previous year of at least one of three acute symptoms (chills, fever, night chills) and one of two chronic symptoms (joint pain, swollen joint(s)) in one or both of two individuals interviewed in a household. Two-hundred-ninety-seven yak from 61 herds were sampled, and 61 household questionnaires were completed. Estimated true prevalence was 0.22 (95% CI: 0.17; 0.28). Poisson regression with generalized estimating equations was used to account for repeated measures within a cluster (herd). Yak in herds reporting abortion occurrence within the previous year were 2.3 times more likely to be seropositive than those in herds not reporting abortion (95% CI: 1.2; 4.2, p = 0.01). For every 10 animal increase in herd number, individual animal seropositivity risk increased by 30% (95% CI: 10%; 50%, p = 0.001). Male yak were 0.7 times as likely to be seropositive as female yak (95% CI: 0.5; 0.9, p = 0.01). Three to five year old yak were 2 times more likely to be seropositive than yak <3 years old (95% CI: 1.3; 3.2, p = 0.003), and yak >5 years old were 4.9 times more likely to be seropositive than yak <3 years old (95% CI: 2.9; 8.1, p < 0.001). Risk of reported brucellosis-like symptoms at the household level was 2 (95% CI: 1.1; 3.5, p = 0.02) times greater for households with herds with >1 reactor, and was 3.6 (95% CI: 1.4; 9.2, p = 0.008) times greater for households reporting the practice of raw milk consumption. These results indicate that yak seropositivity for Brucella spp. is widespread in the region, and is associated with reported human disease. This epidemiologic understanding is essential to the identification of public health opportunities at the interface of Himalayan livestock populations and the transhumant pastoralists that depend on them.


Assuntos
Brucella/imunologia , Brucelose/veterinária , Bovinos/microbiologia , Zoonoses/microbiologia , Criação de Animais Domésticos/métodos , Animais , Anticorpos Antibacterianos/sangue , Brucelose/epidemiologia , Brucelose/imunologia , Brucelose/microbiologia , Estudos Transversais , Feminino , Humanos , Masculino , Nepal/epidemiologia , Fatores de Risco , População Rural , Estudos Soroepidemiológicos , Inquéritos e Questionários
12.
J Am Vet Med Assoc ; 243(9): 1329-33, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-24134585

RESUMO

OBJECTIVE: To estimate the sensitivity, specificity, likelihood ratios, and predictive values of blood ß-hydroxybutyrate (BHB) concentrations in dairy cows immediately prior to surgical correction of left-displaced abomasum (LDA) for determining associations between BHB concentration and removal from the herd ≤ 30 days after surgery and to evaluate postsurgical risk of removal for cows with the BHB concentration that had highest sensitivity and specificity for predicting this outcome. DESIGN: Prospective cohort study. ANIMALS: 136 dairy cows with LDA diagnosed between 5 and 30 days in lactation (ie, days in milk). PROCEDURES: Blood BHB concentration was measured immediately prior to surgery. All cows underwent surgical correction of LDA while standing. Follow-up information was obtained ≥ 30 days after surgery. Receiver operating characteristic curves were used to estimate a critical threshold value for BHB concentration that was associated with removal from the herd, and this value was used in Poisson regression to estimate risk ratio for the same outcome. RESULTS: While controlling for parity in the model, cows with a BHB concentration < 1.2 mmol/L at the time of LDA surgery were 2.5 times as likely (95% confidence interval, 1.3 to 5.0) to be removed from the herd ≤ 30 days after surgery, compared with cows that had a BHB concentration ≥ 1.2 mmol/L. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that blood BHB concentration in dairy cows undergoing surgical correction of LDA may potentially be a useful prognostic indicator for the likelihood of removal from the herd ≤ 30 days after surgery. Further research is needed to evaluate other risk factors that may be associated with this outcome.


Assuntos
Ácido 3-Hidroxibutírico/sangue , Abomaso/cirurgia , Doenças dos Bovinos/sangue , Gastropatias/veterinária , Criação de Animais Domésticos , Animais , Bovinos , Estudos de Coortes , Indústria de Laticínios , Feminino , Lactação , Prognóstico , Fatores de Risco , Gastropatias/cirurgia
13.
Vet J ; 198(3): 560-70, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24054909

RESUMO

Dairy cows pass through a period of negative energy balance as they transition from late gestation to early lactation. Poor adaptation through this period, expressed as excessively elevated concentrations of non-esterified fatty acids (NEFAs) pre- or post-partum and elevated concentrations of ß-hydroxybutyrate post-partum, increases an individual animal's risk of post-partum disease, removal from the herd, reproductive difficulty, and reduced milk production. Field studies have shown that subclinical ketosis often affects 40% of cows in a herd although the incidence can be as high as 80%. Peak incidence occurs at 5 days in milk, and cows that develop subclinical ketosis in the first week of lactation have a higher risk of negative effects and reduced milk production than cows that develop subclinical ketosis in the second week of lactation. Herds with more than a 15-20% prevalence of excessively elevated concentrations of NEFAs and ß-hydroxybutyrate in early lactation have higher rates of negative subsequent events, poorer reproduction, and lower milk yield than herds with a lower prevalence of negative energy balance. This paper reviews (1) strategies for testing of energy-related metabolites, (2) consequences of poor adaptation to negative energy balance (for individual animals and for herds), (3) treatment approaches for affected cows, and (4) economic considerations for testing and treating cows with poor adaptation to negative energy balance.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/terapia , Indústria de Laticínios , Metabolismo Energético , Cetose/veterinária , Ácido 3-Hidroxibutírico/metabolismo , Animais , Bovinos , Doenças dos Bovinos/etiologia , Indústria de Laticínios/economia , Ácidos Graxos não Esterificados/metabolismo , Feminino , Cetose/epidemiologia , Cetose/etiologia , Cetose/terapia , Lactação , Período Pós-Parto
14.
Vet Clin North Am Food Anim Pract ; 29(2): 387-412, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23809897

RESUMO

Dairy cows visit a state of negative energy balance (NEB) as they transition from late gestation to early lactation. At the individual level, there are several metabolic adaptations to manage NEB, including mobilization of nonesterified fatty acids (NEFA) from body fat reserves and glucose sparing for lactogenesis. Based on current pen-level feeding and management practices, strategies to minimize excessive NEB in both the individual and herd should focus on herd-level testing and management. This article reviews strategies for testing and monitoring of excessive NEB at the herd level through individual testing of 2 energy markers: NEFA and ß-hydroxybutyrate.


Assuntos
Ácido 3-Hidroxibutírico/sangue , Doenças dos Bovinos/sangue , Bovinos/fisiologia , Metabolismo Energético/fisiologia , Ácidos Graxos não Esterificados/sangue , Lactação/fisiologia , Doenças Metabólicas/sangue , Ácido 3-Hidroxibutírico/metabolismo , Tecido Adiposo/metabolismo , Animais , Biomarcadores/sangue , Bovinos/metabolismo , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Feminino , Lactação/metabolismo , Doenças Metabólicas/epidemiologia , Doenças Metabólicas/metabolismo , Leite/metabolismo , Gravidez , Reprodução/fisiologia
15.
Parasitol Res ; 112(3): 1247-54, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23315189

RESUMO

The objective was to describe the probability of Cryptosporidium parvum fecal oocyst shedding at different magnitudes of exposure, the pattern of fecal shedding over time, and factors affecting fecal shedding in dairy calves. Within the first 24 h of life, 36 calves were experimentally challenged with C. parvum oocysts at one of four possible magnitudes of oral exposure (1 × 10(3), 1 × 10(4), 1 × 10(5), and 1 × 10(6) oocysts), and 7 control calves were sham dosed. Fecal shedding occurred in 33 (91.7 %) experimentally challenged calves and in none of the control calves. There was a difference in the log-total number of oocysts counted per gram of feces dry weight among the four exposure groups; calves with the lowest magnitude of exposure (1 × 10(3) oocysts) shed less than the other three groups. At higher magnitudes of exposure, there was more variability in the range of fecal oocyst shedding. There was an inverse relationship between the log-total amount of oocysts counted per gram of feces dry weight and the number of days to the onset of fecal shedding per calf, i.e., the more time that elapsed to the onset of fecal shedding, the fewer oocysts that were shed. The pattern of fecal shedding over time for all calves shedding oocysts was curvilinear; the number of oocysts increased with time, reached a peak, and declined. Therefore, the dynamics of oocyst shedding can be influenced in part by limiting exposure among calves and delaying the onset of fecal oocyst shedding.


Assuntos
Doenças dos Bovinos/parasitologia , Criptosporidiose/parasitologia , Cryptosporidium parvum/isolamento & purificação , Fezes/parasitologia , Oocistos , Animais , Bovinos , Modelos Animais de Doenças , Contagem de Ovos de Parasitas , Fatores de Tempo
16.
J Am Vet Med Assoc ; 241(11): 1514-20, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23176246

RESUMO

OBJECTIVE: To evaluate the effect of nutritional plane on health and performance of dairy calves after infection with Cryptosporidium parvum. DESIGN: Randomized, controlled trial. ANIMALS: 20 Holstein bull calves. PROCEDURES: Calves were assigned to a higher plane of nutrition (HPN; 0.30 Mcal intake energy/kg of metabolic body weight using a 28% protein-20% fat milk replacer) or conventional nutrition (CN; 0.13 Mcal intake energy/kg of metabolic body weight using a 20% protein-20% fat milk replacer). Calves were inoculated with C parvum oocysts at 3 days old. Fecal and health scores, oocyst counts, weight gain, dry matter intake, and hematologic variables were measured for 21 days. Data were analyzed with nonparametric and regression methods. Results-Body weight (day 1), serum total protein concentration (day 3), and PCV (day 3) were not different between groups. Oocyst shedding was not different between groups. The PCV was higher in the CN group (40%), compared with the HPN group (32%) at the end of the study. Fecal scores (FS) improved faster in the HPN group (median, -0.1 FS/feeding), compared with the CN group (median, -0.06 FS/feeding). The HPN calves had better average daily gain (ADG) than did CN calves (median, 433 g/d vs -48 g/d, respectively). Feed efficiency (ADG:dry matter intake ratio) was better for HPN calves than CN calves (median, 131.9 g/kg vs -31.4 g/kg). CONCLUSIONS AND CLINICAL RELEVANCE: After a pathogen challenge, calves maintained hydration, had faster resolution of diarrhea, grew faster, and converted feed with greater efficiency when fed a higher plane of nutrition.


Assuntos
Ração Animal/análise , Doenças dos Bovinos/parasitologia , Criptosporidiose/veterinária , Cryptosporidium parvum , Estado Nutricional/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Doenças dos Bovinos/patologia , Criptosporidiose/parasitologia , Indústria de Laticínios , Dieta/veterinária , Masculino
17.
Can Vet J ; 53(4): 378-82, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23024382

RESUMO

Visualization of colonic mesenteric vasculature during transabdominal ultrasonographic examination of horses with colic can be a predictor of right dorsal displacement of the large colon or 180° large colon volvulus, or both. Medical records of 82 horses having had surgical treatment of colic and having received a transabdominal ultrasonographic examination on admission were reviewed. Colonic mesenteric vessels were sonographically identified coursing laterally on the right side of the abdomen in 24 of the 82 cases. Horses with colonic vessels identified on ultrasound were 32.5 times more likely to be diagnosed at surgery with either large colon right dorsal displacement or 180° large colon volvulus than those in which vessels were not seen (P < 0.001). Visualization of colonic mesenteric vessels on ultrasound provided a sensitivity of 67.7%, specificity of 97.9%, positive predictive value of 95.8%, and negative predictive value of 81% for large colon right dorsal displacement or 180° large colon volvulus, or both.


Assuntos
Doenças do Colo/veterinária , Doenças dos Cavalos/diagnóstico por imagem , Volvo Intestinal/veterinária , Mesentério/irrigação sanguínea , Mesentério/diagnóstico por imagem , Animais , Cólica/diagnóstico , Cólica/diagnóstico por imagem , Cólica/veterinária , Doenças do Colo/diagnóstico , Doenças do Colo/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Doenças dos Cavalos/diagnóstico , Cavalos , Volvo Intestinal/diagnóstico por imagem , Masculino , Valor Preditivo dos Testes , Ultrassonografia
18.
J Am Vet Med Assoc ; 241(4): 496-8, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22852576

RESUMO

OBJECTIVE: To determine the apparent prevalence of shedding of Cryptosporidium spp in healthy alpaca crias and their dams on 14 farms in New York and 1 farm in Pennsylvania. DESIGN: Cross-sectional study. ANIMALS: 110 alpaca crias and their 110 dams. PROCEDURES: Fecal samples were obtained from 220 alpacas at 14 alpaca farms in New York and 1 farm in Pennsylvania. For each animal, age, sex, and health condition were recorded. A fecal score (1 = normally formed; 2 = soft or loose; 3 = diarrhetic) was recorded for each cria. Cryptosporidium oocysts were identified in fecal samples by a direct immunofluorescence assay. RESULTS: Apparent prevalence of fecal shedding of Cryptosporidium oocysts was 8% (95% confidence interval, 4% to 15%) in dams and was 7% (95% confidence interval, 3% to 13%) in crias. There was no significant difference in age between dams with positive fecal test results for Cryptosporidium oocysts (median age, 4 years; range, 3 to 8 years) and dams with negative results (median age, 4 years; range, 2.5 to 19 years). No significant difference was found in age between crias with positive fecal test results (median age, 20 days; range, 7 to 53 days) and those with negative results (median, 36 days; range, 2 to 111 days). No significant difference in fecal scores was found between crias with positive versus negative fecal test results. CONCLUSIONS AND CLINICAL RELEVANCE: A higher than previously reported apparent prevalence of fecal shedding of Cryptosporidium oocysts in healthy alpacas was found. A zoonotic risk should be considered, especially for Cryptosporidium parvum.


Assuntos
Camelídeos Americanos , Criptosporidiose/veterinária , Cryptosporidium/isolamento & purificação , Fezes/parasitologia , Animais , Criptosporidiose/parasitologia , Feminino , Masculino , New York/epidemiologia , Oocistos , Pennsylvania/epidemiologia , Prevalência
19.
Am J Vet Res ; 72(11): 1465-75, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22023124

RESUMO

OBJECTIVE: To investigate the effect of opsonization of Rhodococcus equi with R. equi-specific antibodies in plasma on bacterial viability and phagocyte activation in a cell culture model of infection. SAMPLE: Neutrophils and monocyte-derived macrophages from 6 healthy 1-week-old foals and 1 adult horse. PROCEDURES: Foal and adult horse phagocytes were incubated with either opsonized or nonopsonized bacteria. Opsonization was achieved by use of plasma containing high or low concentrations of R. equi-specific antibodies. Phagocyte oxidative burst activity was measured by use of flow cytometry, and macrophage tumor necrosis factor (TNF)-α production was measured via an ELISA. Extracellular and intracellular bacterial viability was measured with a novel R. equi-luciferase construct that used a luminometer. RESULTS: Opsonized bacteria increased oxidative burst activity in adult horse phagocytes, and neutrophil activity was dependent on the concentration of specific antibody. Secretion of TNF-α was higher in macrophages infected with opsonized bacteria. Opsonization had no significant effect on bacterial viability in macrophages; however, extracellular bacterial viability was decreased in broth containing plasma with R. equi-specific antibodies, compared with viability in broth alone. CONCLUSIONS AND CLINICAL RELEVANCE: The use of plasma enriched with specific antibodies for the opsonization of R. equi increased the activation of phagocytes and decreased bacterial viability in the extracellular space. Although opsonized R. equi increased TNF-α secretion and oxidative burst in macrophages, additional factors may be necessary for effective intracellular bacterial killing. These data have suggested a possible role of plasma antibody in protection of foals from R. equi pneumonia.


Assuntos
Infecções por Actinomycetales/veterinária , Broncopneumonia/veterinária , Doenças dos Cavalos/imunologia , Viabilidade Microbiana , Proteínas Opsonizantes/metabolismo , Fagocitose , Rhodococcus equi/imunologia , Infecções por Actinomycetales/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Proteínas de Bactérias/sangue , Proteínas de Bactérias/imunologia , Broncopneumonia/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Cavalos , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Neutrófilos/imunologia , Neutrófilos/metabolismo , Fagócitos/imunologia , Fagócitos/metabolismo , Explosão Respiratória , Rhodococcus equi/fisiologia , Fator de Necrose Tumoral alfa/metabolismo
20.
J Parasitol ; 97(2): 349-51, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21506794

RESUMO

Evaluation of dairy calf feces is often used in research and for clinical decision making to assess severity of diarrhea. However, this has not been validated for agreement between dry matter content and observed fecal consistency. Therefore, a comparison of observed fecal consistency score to fecal percent dry matter and Cryptosporidium parvum oocyst shedding was performed to assess the accuracy of observational scoring as a measure of diarrhea and its association with number of oocysts shed. Fecal samples from 20 dairy calves experimentally infected with C. parvum oocysts were collected daily post-infection and scored on a scale from 1 to 4, with 1 being normal feces to 4 being severe diarrhea. An aliquot of each sample was analyzed for percent dry matter and Cryptosporidium oocyst counts by using immunofluorescent microscopy. Fecal consistency scores of 1, 2, 3, and 4 had median percent dry matter of 20.9, 16.3, 9.6, and 5.8, respectively. Using percent dry matter assessed by fecal consistency scoring were significantly different from each other (P < 0.001). A higher fecal consistency score also was associated with a greater number of Cryptosporidium oocysts shed (P < 0 .0001). Scores of 1, 2, 3, and 4 had median oocyst counts of 0, 0, 1.3 × 106, and 2.8 × 106, respectively. These results suggest that observational scoring is a useful proxy to assess diarrhea in dairy calves.


Assuntos
Doenças dos Bovinos/diagnóstico , Criptosporidiose/veterinária , Cryptosporidium parvum/isolamento & purificação , Diarreia/veterinária , Fezes/parasitologia , Contagem de Ovos de Parasitas/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Criptosporidiose/diagnóstico , Criptosporidiose/parasitologia , Cryptosporidium parvum/crescimento & desenvolvimento , Diarreia/diagnóstico , Diarreia/parasitologia , Fezes/química , Oocistos/crescimento & desenvolvimento , Contagem de Ovos de Parasitas/normas , Água/análise
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