RESUMO
Many calves born on dairy farms are male, but little research to date has focused on the management of these calves. The objective of this study was to survey management practices of preweaned dairy bull calves and compare these practices with those used for heifer calves on the same operations. This study was conducted as part of the USDA National Animal Health Monitoring System Dairy 2014 study and included a sample of 42 operations from 10 states. On average, 2.4% of bull calves died before leaving the operation, with most operations selling bull calves before weaning (97.6%). Bull calves left the operation at an average age of 7.6 d (median = 4 d). Producers reported that 96.3% of bull calves received colostrum. Of bulls that were fed colostrum, the vast majority (95.4%) were hand-fed; the remaining calves received colostrum via a combination of hand-feeding and suckling (3.1%) or by suckling only (1.5%). In contrast, all heifer calves on those operations were only hand-fed colostrum. On average, bull calves received 3.1 L of colostrum at their first feeding at 4.3 h after birth compared with 2.9 L at 2.9 h after birth for heifer calves. In the first 24 h, bull and heifer calves received 4.8 and 5.5 L of colostrum, respectively. Only 21.4% of operations dehorned bull calves; in comparison, heifer calves were dehorned on 90.5% of operations. Few operations used analgesics or anesthetics when dehorning bull calves, whereas 28.9% of operations used anesthetics or analgesics when dehorning heifer calves. Overall, 27.8% of operations castrated bull calves. Of the operations that did castrate bulls, 70.0% used a band at an average age of 6.3 wk; the remaining 30% of operations used a knife at 14.7 wk of age on average. Few operations used analgesics or anesthetics when castrating. These results illustrate differences in the care of bull and heifer calves and suggest the need to improve education regarding recommended colostrum feeding and pain management practices in all calves regardless of sex.
Assuntos
Colostro/fisiologia , Indústria de Laticínios/métodos , Cornos/cirurgia , Orquiectomia/veterinária , Manejo da Dor/veterinária , Desmame , Bem-Estar do Animal , Animais , Bovinos , Masculino , Orquiectomia/métodos , Manejo da Dor/métodos , Estados UnidosRESUMO
The majority of dairy heifer calves in the United States are destined to be dairy replacements. However, many dairy heifer and bull calves die before 6 mo of age. Of these calves, about 6% (more than 500,000 calves) die at birth or shortly after (i.e., currently termed "stillbirth"). An additional 6% of dairy heifers die during the preweaning period. Death loss in dairy calves is primarily due to stillbirths, failure to adapt to extrauterine life, and infectious disease processes. The reasons for preweaning heifer calf deaths caused by infectious diseases are generally categorized based on easily recognizable clinical signs such as digestive disease/scours or respiratory disease. Most causes of calf death can be mitigated by appropriate preventive care or well-tailored treatments, meaning that the typical death loss percentage could be decreased with better management. Producers could gather information on the circumstances near birth and at death if they had appropriate guidance on what details to record and monitor. This paper provides recommendations on data to collect at the time of birth (i.e., calf birth certificate data). The recording of these critical pieces of information is valuable in evaluating trends over time in morbidity and mortality events in dairy calves. Ideally, necropsy examination would substantially improve the identification of cause of death, but even without necropsy, attribution of cause of death can be improved by more carefully defining death loss categories in on-farm record systems. We propose a death loss categorization scheme that more clearly delineates causes of death. Recommendations are provided for additional data to be collected at the time of death. Recording and analyzing birth certificate and death loss data will allow producers and veterinarians to better evaluate associations between calf risk factors and death, with the goal of reducing dairy calf mortality.
Assuntos
Criação de Animais Domésticos/métodos , Declaração de Nascimento , Doenças dos Bovinos/mortalidade , Natimorto/veterinária , Animais , Animais Recém-Nascidos , Animais Lactentes , Bovinos , Indústria de Laticínios , Fazendas , Feminino , Masculino , Parto , Gravidez , Fatores de RiscoRESUMO
The objective of this study was to evaluate management practices and environmental factors associated with cryptosporidiosis and giardiasis in preweaned heifer calves on US dairy operations. This study was conducted as part of the calf component of the National Animal Health Monitoring System's Dairy 2014 study. The calf component included 104 dairy operations in 13 states and was an 18-mo longitudinal study focused on dairy heifer calves from birth to weaning. Fecal samples were collected from 2,249 calves: 839 calves in the West region (California, Colorado, and Washington) and 1,410 calves in the East region (Iowa, Michigan, Minnesota, Missouri, New York, Ohio, Pennsylvania, Vermont, Virginia, and Wisconsin). Fecal samples were collected only once from calves during the preweaning period. Samples were collected from calves 3 to 66 d of age, with a mean of 22 d. Overall, Cryptosporidium and Giardia were detected in 43.1 and 30.5% of fecal samples, respectively. Backward elimination logistic model selection was used after univariate screening to determine which management practices and environmental factors significantly affected the presence of Cryptosporidium or Giardia. The final Cryptosporidium model included herd size, days of age at fecal collection, and average temperature-humidity index for the month of fecal collection (fTHI). Cryptosporidium was found on a higher percentage of large operations (≥500 cows) than small operations (30 to 99 cows). Younger calves were more likely to have a fecal sample positive for Cryptosporidium than samples from older calves. Fecal samples from calves during the warmer parts of the year (fTHI >70) were more likely to be positive for Cryptosporidium than samples collected in colder months (fTHI <20). The final Giardia model included herd size, days of age at fecal collection, average fTHI, failure of passive transfer status, and average daily gain (kg/d) during the preweaning period. Giardia was isolated more frequently from calves on small operations than on large operations and from calves that were older compared with younger calves. Giardia was more frequently isolated in warmer months. Samples from calves with failure of passive transfer were more likely to have Giardia than calves with adequate passive transfer (>10 g/L IgG). Average daily gain during the preweaning period was lower in calves from which Giardia was isolated. These results highlight the factors associated with the presence of Cryptosporidium and Giardia in preweaned dairy heifer calves.
Assuntos
Doenças dos Bovinos/epidemiologia , Criptosporidiose/epidemiologia , Fezes/parasitologia , Giardíase/veterinária , Animais , Animais Lactentes , Bovinos , Doenças dos Bovinos/parasitologia , Cryptosporidium/isolamento & purificação , Feminino , Giardia/isolamento & purificação , Giardíase/epidemiologia , Estudos LongitudinaisRESUMO
Dairy calves shed pathogenic Escherichia coli O157 (O157) in feces and are a potential route of exposure for human infections. As part of the National Animal Health Monitoring System's (NAHMS) Dairy 2014 study, we evaluated farm, animal, and environmental factors associated with O157 presence in dairy heifer calves. For this O157 study, calves were enrolled from 100 dairy operations in 13 states. Each operation collected data from calves from birth to weaning over an 18-mo period. A single fecal sample was collected from 487 calves in western states and from 871 calves in eastern states (n = 1,358 total), and O157 was detected in 2.5% (n = 34) of fecal samples. Descriptive statistics and univariable screening were used to determine which farm practices, environmental factors, and calf health measures were associated with O157 detection. Multilevel logistic models, controlling for dairy operation, were created using backward elimination of screened variables. The final O157 main effects model included variables for source of colostrum, temperature-humidity index (THI), and serum IgG concentration. Higher serum IgG was associated with lower odds of O157 shedding, whereas calves fed colostrum from their own dam had higher odds of O157 shedding than calves fed colostrum from pooled sources. Interaction models showed that THI level modified the effect of colostrum source on O157 shedding; calves with a THI indicative of heat stress had a significantly increased presence of O157 when fed colostrum from a first-lactation dam. The THI level also modified the effects of serum IgG. Calves with thermoneutral or heat stress THI values had increased presence of O157 with poor (<10 g/L) or adequate (10-15 g/L) serum IgG levels compared with those having excellent (≥15 g/L) serum IgG levels. These results highlight factors that influence the presence of O157 in preweaned dairy heifer calves and may be used to guide practices that mitigate shedding through improved animal husbandry.
Assuntos
Animais Lactentes , Doenças dos Bovinos/epidemiologia , Infecções por Escherichia coli/veterinária , Escherichia coli O157/isolamento & purificação , Fezes/microbiologia , Animais , Animais Recém-Nascidos , Bovinos , Doenças dos Bovinos/microbiologia , Colostro , Infecções por Escherichia coli/epidemiologia , Feminino , Lactação , Gravidez , DesmameRESUMO
The objective of this study was to evaluate morbidity and mortality in preweaned dairy heifer calves based on different health, feeding, and management practices, as well as environmental factors. This study was conducted as part of the calf component of the National Animal Health Monitoring System's Dairy 2014 study, which included 104 dairy operations in 13 states. The calf component was an 18-mo longitudinal study focused on dairy heifer calves from birth to weaning; data were collected on 2,545 calves. The percentage morbidity for all calves enrolled in the study was 33.9%. Backward elimination model selection was used after univariate screening to determine which management practices and environmental factors significantly affected morbidity and mortality. The final morbidity model included birth weight, serum IgG concentration, ventilation type, and average temperature-humidity index (THI) during the preweaning period. After controlling for other independent variables in the model, calves born at a higher birth weight had a lower predicted risk of morbidity than calves with a lower birth weight. An increase in serum IgG concentration was associated with decreased morbidity. Calves housed in positive- or cross-ventilated systems had a 2.2 times higher odds of developing disease compared with calves housed in natural ventilation systems. Average THI during the preweaning period was inversely correlated with morbidity; as THI increased, the predicted morbidity risk decreased. The percent mortality for all calves enrolled in the study was 5.0%. The final mortality model included birth weight, serum IgG concentration, amount of fat/day in the liquid diet, and morbidity. After controlling for other independent variables in the model, calves born at a higher birth weight had a lower risk of mortality. An increase in serum IgG concentration decreased the risk of mortality. The odds of mortality were 3.1 times higher in calves fed ≤0.15 kg of fat/d in the liquid diet compared with calves fed ≥0.22 kg of fat/d. The odds of mortality were 4.7 times higher in calves that experienced any disease throughout the preweaning period than in calves with no disease. In summary, morbidity and mortality were both associated with birth weight and serum IgG concentration. Additionally, morbidity was associated with ventilation type and average monthly THI, and mortality was associated with amount of fat per day in the liquid diet and morbidity.
Assuntos
Criação de Animais Domésticos/métodos , Animais Lactentes , Doenças dos Bovinos/mortalidade , Animais , Bovinos , Feminino , Estudos Longitudinais , Parto , Gravidez , Fatores de RiscoRESUMO
Passive transfer of immunity is essential for the short- and long-term health of dairy calves. The objective of this study was to evaluate factors associated with colostrum quality and passive transfer status of US heifer calves. This study included 104 operations in 13 states that participated in the calf component of the National Animal Health Monitoring System's Dairy 2014 study. This 18-mo longitudinal study included 1,972 Holstein heifer calves from birth to weaning. Multivariable mixed linear regression models were selected using backward elimination model selection after univariate screening to determine which factors were associated with colostrum IgG and serum IgG concentrations. The mean colostrum IgG concentration was 74.4 g/L with 77.4% of colostrum samples having IgG concentrations >50 g/L. The final model for colostrum IgG included colostrum source and a categorized temperature-humidity index value (cTHI) for the month before calving. Mean colostrum IgG concentrations were highest for dams in third and higher lactations (84.7 g/L) and lowest for commercial colostrum replacers (40.3 g/L). Colostrum IgG concentrations were highest for cTHI ≥70 (72.6 g/L) and lowest for cTHI <40 (64.2 g/L). The mean serum IgG concentration was 21.6 g/L, with 73.3% of calves having serum IgG concentrations >15 g/L. The final model for serum IgG concentration included region, heat treatment of colostrum, colostrum source, timing to first feeding, volume of colostrum fed in the first 24 h, age of the calf at blood sampling, and colostrum IgG concentration. Mean serum IgG concentrations were highest for calves that received colostrum from first-lactation dams (25.7 g/L) and lowest for calves fed commercial colostrum replacer (16.6 g/L). Serum IgG concentrations were higher for calves fed heat-treated colostrum (24.4 g/L) than for calves fed untreated colostrum (20.5 g/L). Serum IgG concentration was positively associated with the volume of colostrum fed in the first 24 h and colostrum IgG concentration, and negatively associated with the number of hours from birth to colostrum feeding and age (days) at blood collection. Dairy producers should be encouraged to measure the quality of colostrum before administering it to calves and to measure serum IgG or a proxy such as serum total protein or Brix to evaluate passive immunity and colostrum management programs.
Assuntos
Bovinos , Colostro/imunologia , Imunização Passiva/veterinária , Imunoglobulina G/sangue , Animais , Animais Recém-Nascidos , Bovinos/imunologia , Feminino , Estudos Longitudinais , Gravidez , DesmameRESUMO
The objective of this study was to describe preweaned dairy heifer calf management practices on dairy operations across the United States that were used to analyze factors associated with colostrum quality and passive transfer, Cryptosporidium and Giardia, morbidity and mortality, and average daily gain. This study included 104 dairy operations in 13 states that participated in the National Animal Health Monitoring System's Dairy 2014 calf component study. This 18-mo longitudinal study focused on dairy heifer calves from birth to weaning, and data were collected on 2,545 heifer calves. Descriptive statistics were generated regarding colostrum feeding, preweaning housing, milk feeding and consumption, growth, morbidity and mortality, and weaning practices. The majority of calves enrolled were Holsteins (89.4%). Over half the calves (63.2%) enrolled in the study received the majority of their colostrum via bottle; however, 22.1% of calves from 51.0% of operations received colostrum via suckling from their dams. For all calves, the mean time to the first colostrum feeding was 2.8 h, and the average amount of colostrum at the first feeding was 2.9 L, with 4.5 L provided in the first 24 h. The mean serum IgG of all calves was 21.7 g/L; however, 76.0% of operations had at least 1 calf with failure of passive transfer of immunity with a serum IgG below 10 g/L. The majority of calves in the study were housed individually (86.6%). Nonetheless, 20.2% of operations housed some calves in groups, representing 13.4% of all calves. Approximately one-half of the calves in the study (52.3%) were dehorned or disbudded during the preweaning period, with only 27.8% of these calves receiving analgesics or anesthetics during the procedure. Whole or waste milk was the liquid diet type fed to 40.1% of calves, and milk replacer was fed to 34.8% of calves. A combination of milk and milk replacer was fed to 25.1% of calves. Calves, on average, were fed 2.6 L per feeding and fed 2.6 times/d, resulting in a total of 5.6 L of liquid diet fed per day. The mean average daily gain for all calves enrolled in the study was 0.7 kg/d. Fecal samples were collected and almost all operations had at least 1 calf positive for Cryptosporidium (94.2%) or Giardia (99.0%), and 84.6% of operations had calves that tested positive for both Cryptosporidium and Giardia. Over one-third of calves (38.1%) had at least one morbidity event during the preweaning period and the mortality rate was 5.0%. The mean age at weaning was 65.7 d. This study provides an update on dairy heifer raising practices in the United States.
Assuntos
Animais Lactentes , Bovinos , Colostro/imunologia , Indústria de Laticínios/métodos , Desmame , Ração Animal , Animais , Animais Lactentes/crescimento & desenvolvimento , Animais Lactentes/imunologia , Dieta , Feminino , Estudos Longitudinais , Leite , Substitutos do Leite , GravidezRESUMO
The study objective was to evaluate average daily gain (ADG) in dairy heifer calves based on health, feeding, management practices, and environmental factors. This study included 102 operations in 13 states that participated in the calf component of the National Animal Health Monitoring System's Dairy 2014 study. This 18-mo longitudinal study included 1,410 Holstein heifer calves monitored from birth to weaning. The mean ADG from birth to final weight was 0.74 kg/d. Backward elimination model selection in Proc Mixed after univariate screening determined factors that significantly affected ADG. The final model included dam lactation number, singleton versus twin birth, bedding type, Giardia and Cryptosporidium fecal shedding, disease events, a categorized average temperature-humidity index for the preweaning period (pTHI), amount of protein in the liquid diet (kg/d), milk pasteurization, direct-fed microbials, and the interaction between milk pasteurization and direct-fed microbials. After controlling for other independent variables in the model, calves born to first-lactation dams gained less (0.60 kg/d) than calves from second- (0.65 kg/d) or third- or greater-lactation (0.64 kg/d) dams. Singleton calves gained 0.07 kg/d more than twins. Calves bedded with sand or no bedding gained less (0.49 kg/d) than calves on all other bedding types. Calves negative for Cryptosporidium or Giardia at the time of sampling gained 0.03 or 0.02 kg/d more, respectively, than calves that were positive for Cryptosporidium or Giardia. Calves with no disease events gained 0.07 kg/d more than calves with one or more disease events. Calves experiencing an average pTHI <50 gained more (0.67 kg/d) than calves experiencing an average pTHI from 50 to 69 (0.62 kg/d), or ≥70 (0.59 kg/d). Within the range of observed kilograms of protein fed per day in the liquid diet, every additional 0.1 kg of protein fed per day equated to 0.02 kg/d of gain. Calves fed milk replacer with a direct-fed microbial gained less (0.44 kg/d) than calves fed milk replacer without a direct-fed microbial (0.60 kg/d) and calves fed pasteurized or unpasteurized milk regardless of direct-fed microbial use. These results highlight the importance of feeding a quantity and quality of a liquid diet to achieve optimal growth, keeping calves free of disease, the type or status of bedding, and mitigating the effects of temperature and humidity on preweaning ADG.
Assuntos
Animais Lactentes/crescimento & desenvolvimento , Bovinos/crescimento & desenvolvimento , Ração Animal , Animais , Dieta , Feminino , Estudos Longitudinais , Leite , DesmameRESUMO
The objective of this study was to determine the association among different housing and management practices on the prevalence of lameness, hock lesions, and thin cows on US dairy operations. This study was conducted as part of the National Animal Health Monitoring System's Dairy 2014 study, which included dairy operations in 17 states. Size categories were assigned as follows: small (30-99 cows), medium (100-499 cows), and large (≥500 cows). Trained assessors visited 191 dairy operations from March through July 2014 and recorded locomotion and hock scores (on a 3-point scale), and the number of thin cows (body condition score ≤2.25) from a total of 22,622 cows (average 118 cows per farm). The majority of cows (90.4%) were considered to be sound (locomotion score = 1), 6.9% were mild/moderately lame (locomotion score = 2), and 2.7% were severely lame (locomotion score = 3). Similarly, most cows (87.3%) had no hock lesions (hock score = 1), 10.1% had mild lesions (hock score = 2), and 2.6% had severe hock lesions (hock score = 3). A low percentage of cows (4.2%) were thin. Univariate comparisons were performed using PROC LOGLINK, which accounts for study design and weighting. Variables meeting the univariate screening criterion of P < 0.20 were eligible for entry into multivariable models. Statistical significance in the multivariable models was declared at P < 0.05. Large operations had a lower within-herd prevalence of cows with locomotion score ≥2 and locomotion score = 3 compared with small or medium-sized operations. Operations on which cows were kept primarily on pasture had a lower percentage of locomotion score = 3 than those housed in freestall or open/dry lot operations. The use of sand bedding was associated with a lower within-herd prevalence of locomotion score ≥2 than straw/hay or dry/composted manure as the primary bedding material. Sand bedding was also associated with a lower within-herd prevalence of locomotion score = 3 than other bedding types except for rubber mats or mattresses. Operations that housed cows in an open/dry lot had a lower percentage of hock score ≥2 and hock score = 3 than other housing types. Providing sprinklers for heat abatement and having a nutritionist balance rations for cows was associated with a lower percentage of thin cows. Results from this study highlight management practices that may reduce the prevalence of lameness, hock lesions, and thin cows on dairy operations in the United States.
Assuntos
Indústria de Laticínios , Tarso Animal , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Feminino , Abrigo para Animais , Coxeadura Animal/epidemiologia , PrevalênciaRESUMO
AIMS: To estimate prevalence and antimicrobial susceptibility of enterococci in faeces collected in 2007 from U.S. dairy cattle. METHODS AND RESULTS: A total of 718 faecal samples from 122 dairy cattle operations from 17 US States were collected and cultured for the presence of enterococci. One hundred and eighteen of the 122 operations (96·7%) had at least one dairy cow positive for enterococci and 88·7% (637 of 718) of the faecal samples were positive. At least ten different enterococcal species were found on the dairy operations and 90·7% (107 of 118) of the operations were positive for Enterococcus hirae followed by E. faecalis (40·7%; 48 of 118) and E. faecium (39%; 46 of 118). The highest percentage of resistant isolates were to lincomycin (92·3%; 587 of 636), flavomycin (71·9%; 457 of 636) and tetracycline (24·5%; 156 of 636). Multi-drug resistance (MDR) (resistance ≥ 2 antimicrobials) was observed to as many as seven antimicrobials regardless of class. CONCLUSION: In contrast to previous studies, faecal shedding of enterococci in dairy cattle occurred in almost 90% of cows sampled and represented a variety of enterococcal species. SIGNIFICANCE AND IMPACT OF STUDY: Although this study demonstrated a high prevalence of antimicrobial-resistant enterococci from dairy cattle faeces in the United States, the contribution of dairy cattle as a source of antimicrobial-resistant enterococci that can be transmitted to humans remains unclear.
Assuntos
Antibacterianos/farmacologia , Indústria de Laticínios/estatística & dados numéricos , Resistência a Múltiplos Medicamentos , Enterococcus/efeitos dos fármacos , Enterococcus/isolamento & purificação , Fezes/microbiologia , Animais , Bovinos , Farmacorresistência Bacteriana Múltipla , Enterococcus/classificação , Testes de Sensibilidade Microbiana , Prevalência , Estados Unidos/epidemiologiaRESUMO
Noncompliance with current US and European Union (EU) standards for bulk-tank somatic cell count (BTSCC) as well as BTSCC standards recently proposed by 3 US organizations was evaluated using US Dairy Herd Improvement Association (DHI) herds and herds supplying milk to 4 Federal Milk Marketing Orders (FMO). Herds with 15 to 26 tests (frequently monthly) from January 2009 through October 2010 were included. Somatic cell scores (SCS) from 14,854 herds and 164,794 herd-tests were analyzed for DHI herds with ≥10 cows for all tests. Herd test-day SCC was derived as a proxy for BTSCC and was the basis for determining noncompliance and percentage of the milk it represented. For FMO herds, actual milk marketed and BTSCC were available from 27,759 herds and 325,690 herd-tests. A herd was noncompliant for the current EU BTSCC standard after 4 consecutive rolling 3-test geometric means (geometric method) were >400,000 cells/mL. A herd was noncompliant for the current US BTSCC standard after 3 of 5 consecutive monthly BTSCC shipments (frequency method) were >750,000 cells/mL. Alternative proposed standards (600,000, 500,000, or 400,000 cells/mL) also were examined. A third method designated noncompliance when a single 3-mo geometric mean of >550,000 or >400,000 cells/mL and a subsequent test exceeded the same level. Results were examined based on herd size or milk shipped by month. Noncompliance for the current US standard for the 12 mo ending October 2010 in DHI and FMO herds was 0.9 and 1.0%, respectively, compared with 7.8 and 16.1% for the current EU standard. Noncompliance was always greater for the frequency method than for the geometric method and was inversely related to herd size or milk shipped. Using the frequency method at 400,000 cells/mL, noncompliance was 19.1% for DHI herd-tests in herds with <50 cows compared with 1.1% for herds with ≥ 1,000 cows. For FMO herds shipping <900 t, noncompliance was 44.5% using the frequency method at 400,000 cells/mL compared with 8.0% for herds marketing >9,000 t. All methods proposed increased the percentages of herds and shipped milk that exceeded the regulatory limit. Producers will need to place more emphasis on reducing the incidence and prevalence of subclinical mastitis through known management practices such as proper milking techniques, well-functioning milking machines, postmilking teat disinfectant, dry cow treatment, and culling of problem cows to meet any of the proposed new standards.
Assuntos
Leite/normas , Animais , Bovinos , Contagem de Células/veterinária , Indústria de Laticínios/normas , Leite/citologia , Estações do Ano , Estados UnidosRESUMO
The objectives of this study were to test differences in lying and stepping behaviors in lactating cows with altered gait or other signs of pain in the day preceding either corrective claw trimming (CCT) or therapeutic claw trimming (TCT; d -1), including healthy controls (HC) as a reference group, and to analyze the associations between categories of lying and stepping behaviors at d -1 and subsequent submission to CCT or TCT (d 0). In addition, we characterized variations in lying and stepping behaviors within 7 d relative to CCT or treatment for a specific foot condition (TCT). A total of 310 Holstein cows in a USDA-certified organic dairy herd in northern Colorado were enrolled. Cows were affixed with an accelerometer (IceQube, IceRobotics) below the fetlock of one hind leg at 12 ± 8 d in milk and monitored for 6 mo for daily activity [lying time (LY; min/d), lying bouts (LB; no./d), and steps (ST; no./d)]. Cows with altered gait or other signs of pain were submitted to claw trimming (CT; d 0) and differentiated as receiving only corrective interventions (CCT) or as being treated for a lameness disorder (TCT). Concurrent activity from cows not submitted to CT was considered a reference from HC. Daily averages for each activity within ±7 d relative to CT were compared among the 3 groups using linear mixed models (PROC MIXED of SAS; SAS Institute Inc.). Logistic regression analyses with a logit link function (PROC GLIMMIX of SAS) were used to test the associations between categories (lower quartile or less, interquartile range, and higher quartile or greater) of lying and stepping behaviors (LY, LB, and ST) preceding CT (d -1) and subsequent submission to CCT or TCT (d 0). On d -1, average (± standard error) LY was greater in TCT (631 ± 34 min/d) than in CCT (568 ± 22 min/d) and HC (581 ± 13 min/d). Overall, LB were not statistically different among groups (CCT = 18.7 ± 0.02 bouts/d; TCT = 19.6 ± 1.17 bouts/d; and HC = 19.1 ± 0.43 bouts/d). Daily ST were lower in TCT (1,810 ± 126 steps/d) than in CCT (2,803 ± 63 steps/d) and HC (2,542 ± 103 steps/d). The odds (confidence interval in parentheses) of TCT were greater in cows in the high LY [3.27 (2.47-4.33)] and high LB [2.31 (1.77-3.02)] categories at d -1. The low ST category was associated with increased odds of CCT [3.32 (1.96-5.65)] and TCT [8.48 (6.49-11.1)]. We concluded that, under the current experimental conditions, cows requiring TCT evidenced greater overall LY and lower daily ST the day before CT. However, these differences were not consistent throughout days in milk categories within the lactation. Type of CT was partially associated with category of activity the day preceding CT, and the associations were more evident for TCT. The magnitude of the behavioral changes before and after CT and the recovery times posttreatment to approach HC behavioral levels varied depending on specific conditions.
RESUMO
This cross-sectional study evaluated cow comfort measures in free stall dairies across the United States as part of the National Animal Health Monitoring System's Dairy 2007 study. The study was conducted in 17 states and evaluations were completed between March 5 and September 5, 2007. Assessors recorded hygiene and hock scores, number of cows housed in the pen, the number of cows standing with only the front feet in a stall, standing fully in a stall, and lying in a stall. Facility design measures included bedding type, bedding quantity, stall length and width, presence of a neck rail or brisket locator, and relevant distances from the rear and bed of the stall. Of the 491 operations that completed the cow comfort assessment, 297 had Holstein cows housed in free stalls and were included in this analysis. Negative binomial models were constructed to evaluate the following outcomes: the number of cows that were very dirty, had severe hock injuries, stood with front feet in the stall, stood with all feet in the stall, and were lying in the stall. Hygiene was better on farms that did not tail dock cows compared with those that did (5.7 vs. 8.8% were dirty) and on farms located in the study's west region compared with those located in the east region (5.2 vs. 9.7% were dirty). Severe hock injuries were less common on farms in the west than those in the east (0.5 vs. 4.1%). In addition, severe hock injuries were less common on farms that used dirt as a stall base or sand as bedding compared with farms that did not. A higher percentage of cows was standing with front feet in the stall at higher ambient temperatures (incidence rate ratio=1.016) and as time since feeding increased (incidence rate ratio=1.030). A lower percentage of cows were standing with front feet in the stall when the stalls were shorter and when there were fewer cows per stall. Standing fully in a stall was performed by a higher percentage of cows during the summer than during the spring (13.6 vs. 8.1%), when cows were provided free stalls with rubber mats or mattresses, and as the distance from the rear curb to neck rail increased. A higher percentage of cows were lying in a stall when sand bedding was used, when bedding was added more frequently, and during the spring months. Results of this national survey indicate that tail docking provides no benefit to cow hygiene and that stall base and bedding are key factors influencing hock injuries and stall usage on US free stall dairy farms.
Assuntos
Abrigo para Animais/estatística & dados numéricos , Higiene/normas , Tarso Animal/lesões , Bem-Estar do Animal , Animais , Roupas de Cama, Mesa e Banho/efeitos adversos , Bovinos , Estudos Transversais , Pisos e Cobertura de Pisos , Abrigo para Animais/normas , Postura , Estações do Ano , Cauda/cirurgia , Estados Unidos/epidemiologia , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/veterináriaRESUMO
Dairy cow mortality levels in the United States are excessive and increasing over time. To better define cause and effect and combat rising mortality, clearer definitions of the reasons that cows die need to be acquired through thorough necropsy-based postmortem evaluations. The current study focused on organizing information generated from postmortem evaluations into a monitoring system that is based on the fundamentals of conceptual modeling and that will potentially be translatable into on-farm relational databases. This observational study was conducted on 3 high-producing, commercial dairies in northern Colorado. Throughout the study period a thorough postmortem evaluation was performed by veterinarians on cows that died on each dairy. Postmortem data included necropsy findings, life-history features (e.g., birth date, lactation number, lactational and reproductive status), clinical history and treatments, and pertinent aspects of operational management that were subject to change and considered integral to the poor outcome. During this study, 174 postmortem evaluations were performed. Postmortem evaluation results were conceptually modeled to view each death within the context of the web of factors influencing the dairy and the cow. Categories were formulated describing mortality in terms of functional characteristics potentially amenable to easy performance evaluation, management oversight, and research. In total, 21 death categories with 7 category themes were created. Themes included specific disease processes with variable etiologies, failure of disease recognition or treatment, traumatic events, multifactorial failures linked to transition or negative energy balance issues, problems with feed management, miscellaneous events not amenable to prevention or treatment, and undetermined causes. Although postmortem evaluations provide the relevant information necessary for framing a cow's death, a restructuring of on-farm databases is needed to integrate this level of detail into useful monitoring systems. Individual operations can focus on combating mortality through the use of employee training related to postmortem evaluations, detailed forms for capturing necropsy particulars and other relevant information related to deaths, and standardized nomenclature and categorization schemes. As much as anything, the simple act of recognizing mortality as a problem might be the most fundamental step toward controlling its progression.
Assuntos
Doenças dos Bovinos/mortalidade , Doenças dos Bovinos/patologia , Indústria de Laticínios/métodos , Modelos Biológicos , Animais , Bovinos , FemininoRESUMO
Staphylococcus aureus is a major cause of mastitis in dairy cattle. This study estimated the herd prevalence of methicillin-resistant Staph. aureus (MRSA) among US dairy herds by testing bulk tank milk (BTM) samples using genotypic and phenotypic methods. A nationally representative sample of 542 operations had BTM cultured for Staph. aureus, and 218 BTM samples were positive upon initial culture. After 4 wk to 4 mo of frozen storage, 87% of 218 samples (n = 190) were still culture positive for Staph. aureus on blood agar, but none were positive for MRSA on the selective indicator medium CHROMagar MRSA. A duplex PCR was used to detect the Staph. aureus-specific nuc gene and the methicillin resistance gene, mecA, in mixed staphylococcal isolates from the 190 BTM samples that were positive for Staph. aureus after storage. Seven samples tested positive for nuc and mecA, and 2 samples tested positive for mecA only. MecA-positive Staphylococcus spp., but not MRSA, were subsequently isolated from 5 samples, whereas neither mecA-positive Staphylococcus spp. nor MRSA was isolated from the remaining 4 samples. Presence of methicillin-resistant, coagulase-negative Staphylococcus spp. may complicate the detection of MRSA by means of PCR on BTM. Bulk tank milk in the United States is not a common source of MRSA.
Assuntos
Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Leite/microbiologia , Animais , Técnicas Bacteriológicas , Bovinos , Feminino , Genótipo , Staphylococcus aureus Resistente à Meticilina/genética , Fenótipo , Reação em Cadeia da PolimeraseRESUMO
Increasing levels of dairy cow mortality pose a challenge to the US dairy industry. The industry's current understanding of dairy cow mortality is reliant upon descriptions largely based on producer or veterinary assumptions regarding cause of death without the benefit of detailed postmortem evaluations. A thorough necropsy is a superior tool for establishing a cause of death, except for cases involving euthanasia for traumatic accidents or severe locomotor disorders. Information provided from a necropsy examination would be most valuable if it were categorized and combined with cow health information in a complete postmortem evaluation designed to guide future management decisions. The objective of this study was to describe dairy cow deaths on a Colorado dairy over a 1-yr period and explore classification systems for necropsy findings that might inform management actions aimed at reducing dairy cow mortality. Throughout the study period a thorough necropsy examination was performed on every cow that died. Based upon this examination each death was characterized by a proximate cause (i.e., the most likely immediate cause of the death). Each proximate cause of death was then categorized using 3 alternate schemes founded on generalized etiologic principles and influenced by previous clinical history and treatments. These schemes included the broad categories commonly used for classifying findings within a review of literature related to dairy cow mortality, a diagnostic scheme used within the problem-oriented veterinary medical record, and an analysis focusing on the primary physiologic system derangement for each death. A total of 2,067 cows were enrolled during the study period of which 1,468 cows freshened, 507 cows were sold, and 94 cows died, resulting in a mortality risk of 6.4 deaths per 100 lactations at risk. The distribution of deaths by parity was significantly different from the herd distribution at the end of study with the largest percentage of death present in parity > or =4. Postmortem findings attributable to a specific cause of death were present for all but 4 of the 94 deaths. Assignment of the proximate causes of death to categories within the 3 alternate schemes provided a means for classifying necropsy findings and causes of death with different levels of detail. Creating categories with more selective groupings may provide a means for capturing specifics related to deaths that can be used to guide management decisions.
Assuntos
Doenças dos Bovinos/mortalidade , Animais , Bovinos , Doenças dos Bovinos/classificação , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/prevenção & controle , Causas de Morte , Distribuição de Qui-Quadrado , Colorado/epidemiologia , Indústria de Laticínios , Diagnóstico , Feminino , Fatores de Risco , Estações do Ano , Análise de SobrevidaRESUMO
Failure of passive transfer of immunity (FPT) in dairy replacement calves has been linked to increased neonatal morbidity and mortality and long-term decreases in productivity. The purpose of this study was to estimate the prevalence of FPT in US dairy heifer calves in 2007 and to use nationally representative data to investigate associations of FPT with colostrum and calf management practices. A cross-sectional study was conducted by the USDA's National Animal Health Monitoring System between January and August 2007. Producers from 394 operations in 17 states completed survey questions about colostrum and calf management practices, and serum samples were collected from 1,816 healthy heifer calves on those operations. Serum immunoglobulin G (IgG) levels were determined by radial immunodiffusion, and calves were classified as having FPT if the IgG concentration was less than 10 mg/mL. To investigate associations between FPT and management practices, a multivariable analysis was completed using a weighted logistic regression model. The estimated prevalence of FPT in US dairy heifer calves was 19.2%. The odds of FPT were higher for calves on operations that pooled colostrum [odds ratio (OR = 2.2)], allowed nursing (OR = 2.4), or hand fed colostrum more than 4 h after birth (OR = 2.7). The odds of FPT were also higher for calves on operations that did not provide a source of heat during cold weather for calves experiencing a dystocia (OR = 1.6), would not seek veterinary assistance when unable to correctly position a calf for delivery (OR = 2.6), or did not routinely monitor serum proteins in calves as a measure of passive transfer (OR = 13.8). The prevalence of FPT in dairy heifer calves has decreased in the last 15 yr, so progress has been made in this important area of calf management. This study identified several management practices associated with FPT that could be targeted for educational campaigns or further research.
Assuntos
Animais Recém-Nascidos/imunologia , Bovinos/imunologia , Colostro/imunologia , Indústria de Laticínios/estatística & dados numéricos , Imunização Passiva/veterinária , Animais , Feminino , Imunização Passiva/estatística & dados numéricos , Imunoglobulina G/sangue , Modelos Logísticos , Prevalência , Inquéritos e Questionários , Estados Unidos/epidemiologiaRESUMO
Disseminated infection (DI) of Mycobacterium avium subspecies paratuberculosis (MAP) in cattle may impair cow health, potentiate spread of disease, and is a potential food-safety risk. The objectives of this study were to determine the association between severity of histologic enteric lesions and the occurrence of DI, clinical signs, and positive fecal culture and serum ELISA results. Bacteriologic fecal culture and serum ELISA were performed on 40 dairy cows from MAP-infected herds. Cows were classified as having DI if MAP was isolated from any of 11 extra-intestinal tissues collected postmortem. A grade of 0-3, corresponding to the severity of histologically evident granulomatous inflammation was determined for sections of ileum, jejunum, mesenteric lymph node, and ileocolic lymph node. An overall intestinal inflammation (OII) grade of 0-3 was assigned to each cow. The proportion of cows with DI increased with tissue-specific lesion grade and OII grade. All cows with grade 3 inflammation in any single tissue had DI, however, some cows with DI had grade 1 inflammation or no lesions. In general, there was a positive association between OII grade and clinical signs, gross enteric lesions, and positive ELISA and fecal culture results. However, 12% of OII grade 0 cows had clinical signs (explained by other conditions recognized with necropsy), and the proportion of positive ELISA results was lower for OII grade 3 cows relative to grade 2 cows. Although MAP dissemination may occur early in the disease process, histopathology of intestinal tissues may be used to detect a substantial proportion of DI cows.
Assuntos
Anticorpos Antibacterianos/sangue , Doenças dos Bovinos/patologia , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/patologia , Animais , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/epidemiologia , Indústria de Laticínios , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática/veterinária , Fezes/microbiologia , Feminino , Intestino Delgado/microbiologia , Intestino Delgado/patologia , Fígado/patologia , Linfonodos/microbiologia , Linfonodos/patologia , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/diagnóstico , Paratuberculose/epidemiologia , Sensibilidade e Especificidade , Índice de Gravidade de DoençaRESUMO
Dairy cow mortality is an increasingly severe problem for the US dairy industry. The objective of this study was to examine a variety of herd management practices and herd characteristics to identify factors associated with increased cow mortality in US dairy herds. The National Animal Health Monitoring System's Dairy 2002 study surveyed dairy operations in 21 major dairy states. The complete data set included results from 953 dairy farms with a minimum of 30 dairy cows per farm. Associations between dairy cow mortality and 119 a priori-selected management practices or characteristics of 953 operations were evaluated. Eighty of the 119 risk factors explored in a univariate analysis met initial inclusion criteria for further evaluation of association with dairy cow mortality. A multivariable analysis was conducted to explore more complex relationships. The final multivariable model included 7 representative variables: herd levels of respiratory disease, lameness, and antibiotic use for treating sick cows, the percentage of culled cows less than 50 d in milk, the average calving interval, the use of a total mixed ration, and the region of the country. Increased odds of a greater level of mortality on farms was associated with greater percentages of lameness, respiratory disease, and sick cows treated with antibiotics, demonstrating the influence of physical derangements and disease on dairy cow mortality. Increased odds of a greater level of mortality was also associated with feeding a total mixed ration, culling fewer cows in early lactation, and herds located in western, midwestern, and southeastern regions relative to the northeastern United States, pointing to the importance of management decisions and operation characteristics on mortality outcomes. Further, an important interplay between facets of health and management on dairy cow mortality was suggested through the inclusion of the calving interval, with a longer calving interval leading to increased odds of a greater level of mortality on farms. Analysis of a variety of herd characteristics and practices with nationally representative data suggests that several health problems in tandem with aspects of operational construct and management are associated with increasing mortality.
Assuntos
Doenças dos Bovinos/mortalidade , Indústria de Laticínios/estatística & dados numéricos , Animais , Bovinos , Feminino , Análise Multivariada , Fatores de Risco , Estados Unidos/epidemiologiaRESUMO
The primary objective of this study was to compare characteristics of US dairy operations that had one or more nonambulatory cows (unable to rise for any period of time) (cases) with operations that had no nonambulatory cows (controls) during 2004. A secondary objective was to describe factors associated with recovery of the last nonambulatory cow on the operation during 2004. Case dairy operations (n = 1,822) more often fed a total mixed ration [odds ratio (OR) = 2.0; confidence interval (CI): 1.1-3.4], produced more than 9,090 kg of milk (OR = 2.8; CI: 1.8-4.5), and were more likely to be of medium to large herd size (100 or more head of adult cows, OR = 3.7; CI: 2.2-6.2) compared with control dairies (n = 151). Compared with operations where the predominant flooring surface on which lactating cows stood or walked in winter was pasture, operations where pasture was not the predominant surface were at increased risk of having nonambulatory cows (OR = 4.7; CI: 2.2-10.2). Cows nonambulatory for less than 24 h were more likely to recover compared with cows nonambulatory for 24 h or more (OR = 3.0; CI: 2.0-4.4). Cows that received calcium, phosphorus, or potassium while non-ambulatory were more likely to recover (OR = 3.6; CI: 2.1-6.1) than cattle that did not receive these treatments. Cattle that were not repositioned periodically were more likely to recover (OR = 2.1; CI: 1.4-3.1), as were cattle that were not treated by a veterinarian before becoming nonambulatory (OR = 1.9; CI: 1.1-3.3). These findings are consistent with prolonged recumbency and prior history of health issues, respectively. Nonambulatory cattle with hypocalcemia were more likely to recover (OR = 6.0; CI: 3.4-10.7) compared with nonambulatory cows with all other causes of a nonambulatory condition (analyzed collectively as a single variable but including cancer, clinical mastitis, digestive conditions, metabolic imbalances, neurological problems, respiratory disease, other, unknown). The results of this study reveal that the majority of US dairy operations have at least one nonambulatory dairy cow over the course of a year. Additionally, individual animal factors associated with being nonambulatory may lead to improved identification and treatment of animals that are nonambulatory for a prolonged period. From the perspective of recovery, considering euthanasia is appropriate for cows that have been nonambulatory for more than 24 h.