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Oxidative stress may affect new born calves due to high stress suffered around birth. We hypothesized that maternal supplementation with micronutrients and vitamins in late gestation enhance the neonatal calf's antioxidant system, decreasing the occurrence and duration of diarrhea, and improving growth from birth through weaning. To test this hypothesis, 80 multiparous cows were cluster-assigned to treatment groups. Treated group (TG) cows received mineral and vitamin supplementation while control group (CG) cows received saline solution. Feed intake and fecal score were measured daily until the ninth week. Weight and body measurements were registered weekly, and blood samples were collected from postpartum cows and calves after birth and at 7, 14, and 63 days of life. Although CG calves had greater fecal scores (p = 0.01), diarrhea characteristics did not differ. Calves in the TG showed greater starter intake (p = 0.04). Feed efficiency showed a trend with treatment-age interaction (p = 0.06). Calves in the CG had wider hips in the first week (p = 0.03), but not by the ninth week. Total antioxidant status, thiobarbituric acid reactive substances, and haptoglobin did not differ between treatment groups. Serum metabolites showed no differences. Supplementation did not impact calf antioxidant system or growth in the first two months.
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This study aimed to evaluate the effects of direct-fed microbials (DFM) on health and growth responses of preweaning Bos indicus × Bos taurus (Gyr × Holstein) crossbred calves. Ninety newborn heifer calves (initial BW of 35 ± 4.0 kg) were used. At birth, calves were ranked by initial BW and parity of the dam and assigned to: (1) whole milk without DFM supplementation (CON; n = 30), (2) whole milk with the addition of 1.0 g/calf per day of a Bacillus-based DFM (BAC; n = 30), or (3) whole milk with the addition of 1.0 g/calf per day of BAC and 1.2 g/calf per day of Enterococcus faecium 669 (MIX; n = 30). Milk was fed individually during the study (77 d), and the BAC and MIX treatments were offered daily throughout the 77-d preweaning period. All calves were offered a starter supplement and corn silage starting on d 1 and 60 of age, respectively. Milk and starter supplement intake were evaluated daily, and BW was recorded on d 0 and at weaning (d 77). Diarrhea and pneumonia were assessed daily, and fecal samples were collected on d 0, 7, 14, 21, and at weaning (d 77) for assessment of the presence of bacterial and protozoal pathogens via qPCR. All data were analyzed using SAS (v. 9.4) with calf as the experimental unit and using single-df orthogonal contrasts (BAC + MIX vs. CON; BAC vs. MIX). Daily feeding of DFM, regardless of type, improved weaning BW. Odds ratio for occurrence of pneumonia was lower for DFM-supplemented calves, but its occurrence did not differ between BAC and MIX calves. No Salmonella spp. or Escherichia coli F41 were detected in any of the calves. The proportion of calves positive for E. coli F17 was greater for DFM calves on d 7 (92% and 96% vs. 81% for BAC, MIX, and CON, respectively), on d 21 (13% and 26% vs. 7% for BAC, MIX, and CON, respectively), and at weaning (48% and 35% vs. 22% for BAC, MIX, and CON, respectively). For Clostridium difficile, more DFM calves were positive on d 7 (65% and 30% vs. 35% for BAC, MIX, and CON, respectively) and 14 (20% and 28% vs. 7% for BAC, MIX, and CON, respectively), but proportion of positive calves was also greater for BAC versus MIX on d 7. More CON calves were positive for Clostridium perfringens on d 14 (14% vs. 3% and 8% for CON, BAC, and MIX, respectively) compared with DFM-fed calves. Incidence of calves positive for C. perfringens was greater in BAC than MIX on d 7 (50% vs. 18%), and greater for MIX than BAC at weaning (9% vs. 0%). For protozoa occurrence, a lower proportion of DFM calves were positive for Cryptosporidium spp. on d 7 (58% and 48% vs. 76% for BAC, MIX, and CON, respectively), but opposite results were observed on d 21 for Cryptosporidium spp. (3% and 11% vs. 0% for BAC, MIX, and CON, respectively) and Eimeria spp. on d 14 (7% and 8% vs. 0% for BAC, MIX, and CON, respectively) and 21 (50% and 59% vs. 38% for BAC, MIX, and CON, respectively). In summary, DFM feeding alleviated the occurrence of pneumonia and improved growth rates, while also modulating the prevalence of bacteria and protozoa in preweaning Gyr × Holstein calves.
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Ração Animal , Dieta , Desmame , Animais , Bovinos , Dieta/veterinária , Suplementos Nutricionais , Feminino , LeiteRESUMO
Incorporating Curcumin into animal diets holds significant promise for enhancing both animal health and productivity, with demonstrated positive impacts on antioxidant activity, anti-microbial responses. Therefore, this study aimed to determine whether adding Curcumin to the diet of dairy calves would influence ruminal fermentation, hematologic, immunological, oxidative, and metabolism variables. Fourteen Jersey calves were divided into a control group (GCON) and a treatment group (GTRA). The animals in the GTRA received a diet containing 65.1 mg/kg of dry matter (DM) Curcumin (74% purity) for an experimental period of 90 days. Blood samples were collected on days 0, 15, 45, and 90. Serum levels of total protein and globulins were higher in the GTRA group (P < 0.05) than the GCON group. In the GTRA group, there was a reduction in pro-inflammatory cytokines (IL-1ß and IL-6) (P < 0.05) and an increase in IL-10 (which acts on anti-inflammatory responses) (P < 0.05) when compared to the GCON. There was a significantly higher (P < 0.05) concentration of immunoglobulin A (IgA) in the serum of the GTRA than the GCON. A Treatment × Day interaction was observed for haptoglobin levels, which were higher on day 90 in animals that consumed Curcumin than the GCON (P < 0.05). The catalase and superoxide dismutase activities were significantly higher (P < 0.05) in GTRA, reducing lipid peroxidation when compared to the GCONT. Hematologic variables did not differ significantly between groups. Among the metabolic variables, only urea was higher in the GTRA group when compared to the GCON. Body weight and feed efficiency did not differ between groups (meaning the percentage of apparent digestibility of dry matter, crude protein, and acid detergent fiber (ADF) and neutral detergent fiber (NDF). There was a tendency (P = 0.09) for treatment effect and a treatment x day interaction (P = 0.05) for levels of short-chain fatty acids in rumen fluid, being lower in animals that consumed curcumin. There was a treatment vs. day interaction (P < 0.05) for the concentration of acetate in the rumen fluid (i.e., on day 45, had a reduction in acetate; on day 90, values were higher in the GTRA group when compared to the GCON). We conclude that there was no evidence in the results from this preliminary trial that Curcumin in the diet of dairy calves interfered with feed digestibility. Curcumin may have potential antioxidant, anti-inflammatory, and immune effects that may be desirable for the production system of dairy calves.
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Ração Animal , Curcumina , Dieta , Suplementos Nutricionais , Fermentação , Rúmen , Animais , Curcumina/administração & dosagem , Curcumina/farmacologia , Rúmen/metabolismo , Rúmen/efeitos dos fármacos , Bovinos , Ração Animal/análise , Dieta/veterinária , Suplementos Nutricionais/análise , Estresse Oxidativo/efeitos dos fármacos , Masculino , Citocinas/metabolismo , Desmame , Antioxidantes/metabolismo , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , FemininoRESUMO
This study aimed to evaluate the impact of body condition score (BCS) at calving, parity, and the calving season on the performance of dairy cows and their offspring. Data from 521 Holstein cows that calved a female calf and had their BCS evaluated at calving from a single commercial farm located in Southern Brazil were used. Cows were categorized into five BCS classes: class 1: <3.0 (n = 19), class 2: 3.0-3.25 (n = 134), class 3: 3.5-3.75 (n = 160), class 4: 4.0-4.25 (n = 142), and class 5: >4.25 (n = 66). Data were also categorized by calving order (primiparous and multiparous dams) and by calving season. The study was designed as a prospective cohort study. Variables with normal distribution were analyzed by the MIXED procedure of SAS, while binary outcomes were analyzed by the GLIMMIX procedure of SAS. Daughters from primiparous dams were born lighter (39.1 ± 0.42 vs. 41.4 ± 0.29 kg, p < 0.01), but they had the same weights as the daughters from multiparous cows at weaning (121.5 ± 1.67 vs. 120.4 ± 1.58 kg, p = 0.20). As expected, primiparous cows showed lower (p < 0.01) 305-day milk yields than multiparous ones: 8633 ± 363 vs. 10,761 ± 249 kg, respectively. Regarding the calving season, cows that calved in the winter were the most productive ones, and those that calved in the fall had lower milk yields (p = 0.01). Calves born in the winter were heavier at birth (p < 0.01), calved younger (p = 0.04), and produced more milk at first lactation (p = 0.03). The BCS class had an impact (p < 0.01) on calf birth weights; daughters from Class 1 cows (BCS < 3.0) were lighter (38.0 ± 1.0 kg) than the calves from Class 5 cows with a BCS > 4.25 (41.9 ± 0.57 kg). Calves from dams with a BCS < 3 (Class 1) had a 31.8% culling rate until weaning, while calves from cows with a BCS of 3.0-3.25 (Class 2) had a 9.6% culling rate (p = 0.12). These results suggest that maternal and environmental factors, such as calving season and parity, in addition to the dams' body condition score at calving, are associated with different offspring performances.
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Rotavirus A (RVA) is amongst the most widespread causes of neonatal calf diarrhea. Because subclinical infections are common, the diagnosis of RVA-induced diarrhea cannot rely solely on molecular viral detection. However, RT-qPCR allows for quantification of RVA shedding in feces, which can be correlated with clinical disease. Here, we determine an optimal cutoff of rotaviral load quantified by RT-qPCR to predict RVA causality in diarrheic neonate calves, using RVA antigen-capture ELISA as reference test. Feces from 328 diarrheic (n = 175) and non-diarrheic (n = 153), <30-day-old dairy calves that had been tested by ELISA and tested positive by RT-qPCR were included. Of 82/328 (25.0%) ELISA-positive calves, 53/175 (30.3%) were diarrheic, whereas 124/153 (81.0%) non-diarrheic calves tested negative by ELISA. The median log10 viral load was significantly higher in diarrheic vs. non-diarrheic and ELISA-positive vs. -negative calves, indicating a higher viral load in diarrheic and ELISA-positive calves. A receiver operating characteristic (ROC) analysis was conducted using the viral loads of the 175 diarrheic calves that had tested either positive (n = 53, cases) or negative (n = 122, controls) by ELISA. The optimal log10 viral load cutoff that predicted RVA causality in diarrheic calves was 9.171. A bootstrapping procedure was performed to assess the out-of-bag performance of this cutoff point, resulting in sensitivity = 0.812, specificity = 0.886, area under the curve = 0.922, and positive and negative diagnostic likelihood ratios of 11.184 and 0.142, respectively. The diagnostic accuracy of the cutoff was excellent to outstanding. This information will help in the interpretation of RVA RT-qPCR results in feces of diarrheic calves submitted for laboratory testing.
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Resumen El estrés por frío en los terneros puede ser muy perjudicial para su salud y rendimiento futuro. El objetivo del presente trabajo fue evaluar el efecto de las condiciones de manejo de la crianza artificial y su relación con estrés por frío en terneros de tambo. Se evaluaron 160 terneros durante las primeras horas de la mañana, y se registró si los animales poseían capa o no y si disponían o no de cama. Se observó si contaban con reparo para limitantes climáticas. También se registró la temperatura rectal y si temblaban o no. Se consideró que terneros con temperatura rectal igual o inferior a 37,2 °C se encontraban en estrés por frio. El análisis estadístico de los datos se hizo mediante la prueba no paramétrica de Chi cuadrado y se calculó la probabilidad de ocurrencia mediante Odds Ratio. Encontrándose que los terneros en condiciones de estrés presentaron 4,93 veces mayor probabilidad de temblar; que disponer de cama fue favorable para prevenir el estrés (0,027), que las capas plásticas incrementaron la probabilidad de sufrir de estrés (0,006) y que proveer reparo a los animales tiene un efecto positivo en la prevención del estrés por frío (p = 0,027) en los terneros de tambo.
Abstract Cold stress in calves can be very detrimental to their health and performance. The aim of this work was to evaluate the effect of artificial rearing management conditions and their relationship to cold stress in dairy calves. A total of 160 calves were evaluated during the early morning hours and it was recorded whether or not the animals had cape and whether or not they had bed in pens. Also, it was observed if they had protection for climatic limitations. Rectal temperature and whether or not they were shivering were also recorded. Calves with rectal temperature equal to or lower than 37.2 °C were considered to be in cold stress. The statistical analysis of the data was performed using the non-parametric Chi-square test and the probability of occurrence was calculated using Odds Ratio. It was found that calves under stress conditions were 4.93 times more likely to shiver; that having bed in pens was favorable for preventing stress (0.027), that plastic cape increased the probability of suffering from stress (0.006) and that providing shelter to animals had a positive effect on the prevention of cold stress (p = 0.027) in dairy calves.
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Scours is the most common disease in dairy calves, and it is a multifactorial syndrome complex. Cryptosporidium sp. (C. sp.), rotavirus group A (RVA), and bovine coronavirus (BCoV) are the three main pathogens associated with scours. The objective of this study was to identify potential factors associated with scours, C. sp., RVA, and BCoV infections in preweaned dairy calves from Lerma Valley in Salta Province, Argentina. A total of 488 preweaned calves from 19 dairy farms located in the Lerma Valley were enrolled in this observational study. One fecal sample was collected from each calf between one week and two months of age for assessment of C. sp., RVA, and BCoV infection status. Cryptosporidium sp. oocysts and RVA and BCoV antigens in fecal samples were assessed using microscopic observation and indirect enzyme-linked immune sorbent assay (iELISA), respectively. A voluntary questionnaire was developed and used to collect data regarding management practices from the participants' farms. The data were analyzed using multivariable logistic regression models. Scours incidence was 35.4%, and a greater proportion of calves younger than 20 days were affected. Of the fecal samples, 18% and 9.5% tested were positives for C. sp. and RVA, respectively, while BCoV was detected only in two calves. Furthermore, 84.2% and 63.1% of the farms tested positive for Cryptosporidium sp. and RVA, respectively. In addition, the following variables were associated with higher odds of having scours: (1) herd size (>300 milking cows; OR = 1.7), (2) calf age (<20 days of age; OR = 2.2), (3) RVA and C. sp. test (positive test; RVA OR = 2.6; C. sp. OR = 3), calf feeding practices (feeding milk replacer; OR = 1.81), and newborn calf management practices (calf moved from maternity pen <6 h after calving; OR = 1.7). Concerning RVA infection, calves less than 20 days of age (OR = 2.6) had a higher chance of testing positive for RVA, while calves that remained in the calving pen for less than 6 h after calving had a lower chance (OR = 0.3). On the other hand, for C. sp. infection, large farm size (>300 milking cows; OR = 1.2) and young calf age (<20 days of age; OR = 4.4) indicated a higher chance of testing positive for C. sp., while calves belonging to farms that fed frozen colostrum (OR = 0.2) had a lower chance of becoming infected with C. sp. The result of this study indicated that scours is a prevalent disease in farms of the Lerma Valley, Salta, Argentina, and that RVA and C. sp. infections, along with specific farm management practices, might be important contributing factors that could increase the chance of NCS in dairy farms.
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Neonatal calf diarrhea (NCD) and mortality cause significant losses to the dairy industry. The preweaning dairy calf mortality risk in Uruguay is high (15.2%); however, causes for these losses are largely unknown. This study aimed to assess whether various pathogens were associated with NCD and death in Uruguayan dairy calves and whether these infections, diarrhea, or deaths were associated with the failure of transfer of passive immunity (FTPI). Contemporary diarrheic (n = 264,) and non-diarrheic (n = 271) 1- to 30-day-old calves from 27 farms were sampled. Feces were analyzed by antigen-capture ELISA for Cryptosporidium spp., rotavirus, bovine coronavirus, and Escherichia coli F5+, RT-PCR for bovine astrovirus (BoAstV), and bacterial cultures for Salmonella enterica. Blood/serum was analyzed by RT-PCR or antigen-capture ELISA for bovine viral diarrhea virus (BVDV). Serum of ≤ 8-day-old calves (n = 95) was assessed by refractometry to determine the concention of serum total proteins (STP) as an indicator of FTPI. Whether the sampled calves died before weaning was recorded. At least one pathogen was detected in 65.4% of the calves, and this percentage was significantly higher in diarrheic (83.7%) versus non-diarrheic (47.6%) calves. Unlike the other pathogens, Cryptosporidium spp. and rotavirus were associated with NCD. Diarrheic calves, calves infected with any of the pathogens, and calves infected with rotavirus had significantly lower concentrations of STP. Diarrheic calves had higher chances of dying before weaning than non-diarrheic calves. Diarrheic calves infected with S. enterica were at increased risk of mortality. Controlling NCD, salmonellosis, cryptosporidiosis, and rotavirus infections, and improving colostrum management practices would help to reduce calf morbi-mortality in dairy farms in Uruguay.
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Doenças dos Bovinos/etiologia , Doenças dos Bovinos/mortalidade , Diarreia/veterinária , Animais , Animais Recém-Nascidos , Astroviridae/isolamento & purificação , Estudos de Casos e Controles , Bovinos , Cryptosporidium/isolamento & purificação , Indústria de Laticínios/métodos , Diarreia/etiologia , Diarreia/mortalidade , Vírus da Diarreia Viral Bovina/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/veterinária , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Fezes/parasitologia , Fezes/virologia , Feminino , Imunização Passiva/veterinária , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Rotavirus/isolamento & purificação , Salmonella enterica/isolamento & purificação , Inquéritos e Questionários , Síndrome , Uruguai/epidemiologiaRESUMO
[This corrects the article DOI: 10.3389/fvets.2020.00562.].
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(1) Background: Ruminants often face stressful situations throughout their productive lives. More specifically, pre-weaning dairy calves are exposed to novel environments, feedstuffs, and pathogens that affect their health and performance. Hence, alternatives that reduce stress and promote growth of pre-weaning dairy calves are warranted. Therefore, this study evaluated the effects of biweekly bovine appeasing substance (BAS) administration on performance and disease incidence in dairy Gir × Holstein female calves prior to weaning. (2) Methods: At birth, 140 female Gir × Holstein calves were randomly assigned to receive BAS (SecureCattle; (IRSEA Group, Quartier Salignan, France; n = 70) or placebo (BAS carrier, diethylene glycol monoethyl ether; CON; n = 70) biweekly until weaning (70 days of age). Calves were allocated into individual housing at random, with no physical contact between treatments to avoid cross-contamination. Experimental treatments (5 mL) were applied topically to the nuchal skin area of each calf. Throughout the experimental period, all animals were observed daily for medical conditions (diarrhea, pneumonia, and others), medical/pharmacological interventions were recorded, and the costs related to these procedures were analyzed. Concurrently with treatment application, calves were individually weighed, and data were analyzed using animal as the experimental unit. (3) Results: Treatment × day and treatment × period (14-day interval) interactions were observed for body weight (BW) and average daily gain (ADG; p ≤ 0.05), respectively. Calves receiving BAS had greater BW at weaning (p = 0.02) and tended to have a greater BW on day 56 (p = 0.06). Similarly, ADG was greater for BAS from days 42 to 56 (p = 0.04) and tended to be greater from days 56 to weaning (p = 0.10). No differences were observed on the overall occurrence of diseases (p = 0.92), whereas the most common observed diseases were diarrhea and pneumonia. The incidence and mean age at which animals were detected with these diseases did not differ (p ≥ 0.46). Nonetheless, CON calves detected with disease had a reduced ADG vs. BAS-administered counterparts (p < 0.01). No differences were observed between disease-diagnosed BAS vs. healthy CON, but healthy BAS had a greater ADG vs. healthy CON (p = 0.03). A treatment effect was observed for the cost per head of each pharmacological intervention (p = 0.05). (4) Conclusions: In summary, BAS administration at a 14-day interval improved performance and reduced the costs of pharmacological interventions of pre-weaning Gir × Holstein dairy calves.
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Cryptosporidium parvum, a major cause of diarrhea in calves, is of concern given its zoonotic potential. Numerous outbreaks of human cryptosporidiosis caused by C. parvum genetic subtypes are reported yearly worldwide, with livestock or water being frequently identified sources of infection. Although cryptosporidiosis has been reported from human patients in Uruguay, particularly children, epidemiologic information is scant and the role of cattle as reservoirs of zoonotic subtypes of C. parvum has not been explored. In this study, we aimed to (a)-identify C. parvum subtypes infecting dairy calves in Uruguay (including potentially zoonotic subtypes), (b)-assess their association with calf diarrhea, (c)-evaluate their spatial clustering, and (d)-assess the distance of infected calves to surface watercourses draining the farmlands and determine whether these watercourses flow into public water treatment plants. Feces of 255 calves that had tested positive for Cryptosporidium spp. by antigen ELISA were selected. Samples had been collected from 29 dairy farms in seven Uruguayan departments where dairy farming is concentrated and represented 170 diarrheic and 85 non-diarrheic calves. Selected samples were processed by nested PCRs targeting the 18S rRNA and gp60 genes followed by sequencing to identify C. parvum subtypes. Of seven C. parvum subtypes detected in 166 calves, five (identified in 143 calves on 28/29 farms) had been identified in humans elsewhere and have zoonotic potential. Subtype IIaA15G2R1 was the most frequent (53.6%; 89/166), followed by IIaA20G1R1 (24.1%; 40/166), IIaA22G1R1 (11.4%; 19/166), IIaA23G1R1 (3.6%; 6/166), IIaA17G2R1 (3%; 5/166), IIaA21G1R1 (2.4%; 4/166), and IIaA16G1R1 (1.8%; 3/166). There were no significant differences in the proportions of diarrheic and non-diarrheic calves infected with any of the C. parvum subtypes. Two spatial clusters were detected, one of which overlapped with Uruguay's capital city and its main water treatment plant (Aguas Corrientes), harvesting surface water to supply ~1,700,000 people. Infected calves on all farms were within 20-900 m of a natural surface watercourse draining the farmland, 10 of which flowed into six water treatment plants located 9-108 km downstream. Four watercourses flowed downstream into Aguas Corrientes. Calves are reservoirs of zoonotic C. parvum subtypes in Uruguay and pose a public health risk.
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Resumen Dentro de los factores de estrés a los que puede estar expuesto el ganado lechero el relativo al calor es uno de los más conocidos y estudiados en vacas lecheras por el impacto que tiene sobre la producción láctea. Sin embargo, este nivel de conocimiento no se repite en relación a los terneros en crianza, por tal motivo el objetivo del presente trabajo fue el de estudiar el impacto del estrés por calor en esta categoría. Se monitorearon 246 terneros pertenecientes a 19 tambos en días con ITH ≥ 72 para la franja horaria de 12 a 15. Se categorizaron los registros obtenidos en: estrés ligero, moderado o severo. Se registró la posibilidad o no de acceder a sombra, el disponer o no de agua para consumo, la posición y la actividad principal que desarrollaba, también se evaluó la temperatura rectal (TR) y la frecuencia respiratoria (FR). Los datos fueron analizados mediante ANOVA. La comparación entre medias se realizó con el test Tukey (α=0,05) y el análisis de correlación con el test de Spearman. Se utilizó el programa InfoStat versión 2019p. En lo que refiere a actividad, no se observaron diferencias estadísticamente significativas. Sin embargo, sí se detectaron diferencias (p=0,0138) en la posición de aquellos animales expuestos a condiciones de estrés moderado vs. severo. La TR promedio fue diferente (p=0,0063) entre los animales de la categoría estrés lijero respecto a las otras dos categorías (> 39,2 °C). El valor promedio relativo a la FR resultó superior (p<0,0001) en los terneros bajo estrés severo (>80 rpm). La correlación hallada para la variable ITH respecto de TR resultó de 0,25 (p=0,0001), mientras que para FR fue de 0.33 (p<0,0001). En relación a las prácticas implementadas se registró que el 26 % de los terneros no contaban con sombra ni agua al momento de la visita.
Abstract Heat stress impact on physiological and behavioral parameters in dairy calves. Among the stress factors to which dairy cattle is exposed heat is one of the most studied due to the impact it has on milk production. However, there is lack of information regarding this stress condition in calves compared to the one related to adult animals. The aim of this paper was to study the relevance of heat stress in dairy calves. For the experiment 246 dairy calves from 19 dairy farms were monitored in days with Temperature Humidity Index (ITH) above 72 between 12:00 pm and 03:00 pm. Heat stress related to ITH was categorized in three degrees: low, moderate and sever stress. Additional information was taken during the visit: shade access, water availability, body position, activity being developed, rectal temperature (TR) and respiratory rate (FR). Data were analyzed using ANOVA. Comparison between median values was analyzed with Tukey´s test (α=0,05) and correlation analysis with Spearman´s test. The software used to analyze statistical data was Infostat version 2019. Differences were found in the body position between animals exposed to sever stress versus those with moderate stress (p=0.0138). However, there were no differences in animal activity in any of the temperature exposures. Results on average rectal temperature (TR) showed differences (p=0.0063) between animals with low stress and those with severe and moderate stress (> 39.2 °C). Relative average of FR was higher (p<0.0001) on calves under sever heat stress, reaching above 80 breaths per minute. The correlation coefficient between ITH and TR was 0.25 (p=0.0001), and between ITH and TR was 0.33 (p<0.0001). Regarding the practices implemented on the farms was noted that 26% of calves did not have shade or water available at the moment data was taken.
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The etiological agents involved in a bovine respiratory disease (BRD) outbreak were investigated in a dairy heifer calf rearing unit from southern Brazil. A battery of PCR assays was performed to detect the most common viruses and bacteria associated with BRD, such as bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine alphaherpesvirus 1 (BoHV-1), bovine coronavirus (BCoV), bovine parainfluenza virus 3 (BPIV-3), Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis. Bronchoalveolar lavage fluid (BALF) samples were taken from 21 heifer calves (symptomatic n = 15; asymptomatic n = 6) that, during the occurrence of the BDR outbreak, were aged between 6 and 90 days. At least one microorganism was detected in 85.7 % (18/21) of the BALF samples. Mixed infections were more frequent (72.2 %) than single infections (27.7 %). The interactions between viruses and bacteria were the most common in coinfections (55.5 %). The frequencies of BRD agents were 38.1 % for BRSV, 28.6 % for BVDV, 33.3 % for BCoV, 42.85 % for P. multocida, 33.3 % for M. bovis, and 19 % for H. somni. BoHV-1, BPIV-3, and M. haemolytica were not identified in any of the 21 BALF samples. Considering that BALF and not nasal swabs were analyzed, these results demonstrate the etiological multiplicity that may be involved in BRD outbreaks in dairy calves.
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Líquido da Lavagem Broncoalveolar/microbiologia , Doenças dos Bovinos/microbiologia , Surtos de Doenças/veterinária , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Animais , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/etiologia , Coronavirus Bovino/genética , Coronavirus Bovino/isolamento & purificação , Indústria de Laticínios , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/isolamento & purificação , Técnicas de Diagnóstico Molecular/veterinária , Mycoplasma bovis/genética , Mycoplasma bovis/isolamento & purificação , Pasteurella multocida/genética , Pasteurella multocida/isolamento & purificação , Pasteurellaceae/genética , Pasteurellaceae/isolamento & purificação , Reação em Cadeia da Polimerase , Vírus Sincicial Respiratório Bovino/genética , Vírus Sincicial Respiratório Bovino/isolamento & purificação , Infecções Respiratórias/etiologia , Infecções Respiratórias/veterináriaRESUMO
Salmonella enterica is an important animal and human pathogen that can cause enteritis and septicaemia in calves. Generally, antibiotics are prescribed for the treatment of salmonellosis in dairy calves. Here, we report the isolation of antibiotic resistant S. enterica serotypes from calves, including multidrug-resistant isolates. A total of 544 faecal samples from live healthy and diarrheic dairy calves from 29 commercial dairy farms and organ samples from 19 deceased calves that succumbed to salmonellosis in 12 commercial dairy farms in Uruguay were processed for selective S. enterica culture. In total, 41 isolates were serotyped, and susceptibility to 14 antibiotics, from 9 classes of compounds, was evaluated by disk-diffusion test. The minimum inhibitory concentration (MIC) was determined by microdilution. Salmonella Typhimurium was the most frequent serotype, followed by S. Dublin and S. Anatum. Whether determined by diffusion assay or microdilution, resistance to tetracycline, streptomycin and ampicillin were the most frequently pattern found. Based on MIC, 5 isolates were resistant to at least one antibiotic, 21 were resistant to 2 antibiotics, and 14 were multidrug-resistant (resistant to at least one antibiotic in 3 different categories of antibiotics). Eleven different resistance patterns were found. Multidrug resistance in S. enterica is a concern for animal and public health not only because of its zoonotic potential but also due to the possibility of transfer resistance determinants to other bacterial genera. This represents the first report of the antibiotic resistance in S. enterica in dairy farms in Uruguay.
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Farmacorresistência Bacteriana Múltipla , Salmonelose Animal/microbiologia , Salmonella enterica/isolamento & purificação , Animais , Antibacterianos/farmacologia , Bovinos , Indústria de Laticínios , Fezes/microbiologia , Testes de Sensibilidade Microbiana , Salmonella enterica/efeitos dos fármacos , UruguaiRESUMO
Cryptosporidiosis of calves is caused by the enteroprotozoan Cryptosporidium spp. The disease results in intense diarrhea of calves associated with substantial economic losses in dairy farming worldwide. The aim of this study was to determine calf, herd, and within-herd Cryptosporidium prevalence and identify Cryptosporidium species and subtypes in calves with diarrhea in intensive dairy herds in central Argentina. A total of 1073 fecal samples were collected from 54 randomly selected dairy herds. Cryptosporidium-oocysts were isolated and concentrated from fecal samples using formol-ether and detected by light microscopy with the modified Ziehl-Neelsen technique. Overall prevalence of oocyst-excreting calves was found to be 25.5% (274/1073) (95% C.I. 22.9; 28.1%). Of the herds studied, 89% (48/54) included at least one infected calf, whereas within-herd prevalence ranged from the absence of infection to 57% (20/35). A highly significant association was found between the presence of diarrhea and C. parvum infection (χ2 = 55.89, p < 0.001). For species determination, genomic DNA isolated from oocyst-positive fecal samples was subjected to PCR-RFLP of the 18S rRNA gene resulting exclusively in Cryptosporidium parvum identification. C. parvum isolates of calves displaying diarrhea and high rate of excretion of oocysts were subtyped by PCR amplification and direct sequencing of the 60 kDa glycoprotein (GP60) gene. Altogether five GP60 subtypes, designated IIaA18G1R1, IIaA20G1R1, IIaA21G1R1, IIaA22G1R1, and IIaA24G1R1 were identified. Interestingly, IIaA18G1R1 and IIaA20G1R1 were predominant in calves with diarrhea and high infection intensity. Notably, IIaA24G1R1 represents a novel, previously unrecognized C. parvum subtype. The subtype IIaA18G1R1, frequently found in this study, is strongly implicated in zoonotic transmission. These results suggest that calves might be an important source for human cryptosporidiosis in Argentina.
Assuntos
Doenças dos Bovinos/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium parvum/classificação , Cryptosporidium/classificação , Diarreia/veterinária , Animais , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/parasitologia , Criptosporidiose/parasitologia , Criptosporidiose/transmissão , Cryptosporidium/genética , Cryptosporidium/isolamento & purificação , Cryptosporidium parvum/genética , Cryptosporidium parvum/isolamento & purificação , Diarreia/epidemiologia , Diarreia/parasitologia , Fezes/parasitologia , Feminino , Glicoproteínas/genética , Humanos , Oocistos , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , Prevalência , ZoonosesRESUMO
There are few reports about the isolation of Mycoplasma species associated with cattle disease in Argentina. In this work we describe the detection of Mycoplasma leachii associated with disease in dairy calves in Santa Fe Province, Argentina. Samples obtained from a 4 day-old dairy calf suffering from polyarthritis and from two other calves, one with arthritis and the other one with a mandibular abscess, were subjected to microbiological culture. Classical culture and generic PCR confirmed the presence of Mycoplasma spp. The spacer region between the 16S and 23S ribosomal RNA gene from the first isolate was amplified and sequenced. The sequence obtained showed 99% identity with M. leachii. A PCR was developed to amplify a specific fragment of the 16S-23S ITS region corresponding to M. leachii, which allowed to identify the isolates associated with disease in calves.
Existen pocos informes acerca del aislamiento de especies de Mycoplasma asociadas con enfermedades del ganado en Argentina. En esta comunicación se describe el aislamiento de Mycoplasma leachii asociado a enfermedad en terneros de tambo en la provincia de Santa Fe, Argentina. Se obtuvieron muestras de un ternero de 4 días de vida con poliartritis, de un ternero con artritis y uno con un absceso mandibular. A partir del cultivo clásico se detectó la presencia de Mycoplasma, lo cual fue confirmado por PCR genérica. Se amplificó y secuenció la región ITS 16S-23S a partir del primer aislamiento, mostrando una identidad del 99% con Mycoplasma leachii. Se desarrolló una PCR para amplificar un fragmento específico de la región ITS 16S-23S correspondiente a M. leachii, que permitió identificar los aislamientos asociados con enfermedad en terneros.
Assuntos
Artrite/microbiologia , Doenças dos Bovinos/diagnóstico , Mycoplasma bovis/isolamento & purificação , Mycoplasma/patogenicidade , Reação em Cadeia da Polimerase/veterinária , Diagnóstico/análiseRESUMO
The intra-species genetic diversity of Cryptosporidium parvum in dairy cattle farms in the central area of Colombia was investigated using a multilocus fragment typing approach with nine variable-number tandem-repeat (VNTR) loci and the gp60 gene. Genomic DNA of 70 C. parvum isolates from pre-weaned calves in 32 farms was analysed. Most markers showed two (ML1, MSB, CP47, and MSC6-7) or three alleles (5B12, Cgd2_3850, and Cgd6_5400), although they exhibited a major allele accounting for more than 69% of specimens, which explains their low discriminatory index. The TP14 microsatellite was monomorphic while a total of six alleles were found at the ML2 microsatellite. The two novel allelic variants (219bp, 245bp) exhibited by more than 36% of specimens at the latter locus were a remarkable finding. The 10-markers typing tool provided a Hunter-Gaston discriminatory value of 0.940 (95% CI, 0.918 - 0.961) and differentiated 22 multilocus subtypes (MLTs). Nevertheless, the combination of the three most informative markers (ML2, gp60, and Cgd2_3850) differentiated 68% of MLTs and hardly impaired the discriminatory index. The fact that many MLTs (13/22) were distinctive for individual farms provides evidence for the endemic nature of the infection and the major role played by transmission within farms. The eBURST algorithm suggested a low degree of genetic divergence. All but three MLTs were clustered in a clonal complex with a star-like topology typical of clonal expansion, however linkage analysis did not find evidence of linkage disequilibrium. Bayesian analysis also identified a genetic structure with K = 3 being the best estimation of ancestral clusters, although a large proportion of isolates (35%) could not be allocated to a single population, which indicates their mixed origin. The results confirm the genetic distinctiveness of C. parvum in cattle farms in this geographical area. This is the first multilocus analysis on the intra-specific variability of Cryptosporidium from calves in South America.
Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/genética , Criptosporidiose/epidemiologia , Criptosporidiose/genética , Cryptosporidium parvum/genética , Cryptosporidium parvum/isolamento & purificação , Variação Genética , Animais , Teorema de Bayes , Bovinos , Colômbia/epidemiologia , Indústria de Laticínios , Genótipo , Desequilíbrio de Ligação , Repetições de Microssatélites , Repetições MinissatélitesRESUMO
There are few reports about the isolation of Mycoplasma species associated with cattle disease in Argentina. In this work we describe the detection of Mycoplasma leachii associated with disease in dairy calves in Santa Fe Province, Argentina. Samples obtained from a 4 day-old dairy calf suffering from polyarthritis and from two other calves, one with arthritis and the other one with a mandibular abscess, were subjected to microbiological culture. Classical culture and generic PCR confirmed the presence of Mycoplasma spp. The spacer region between the 16S and 23S ribosomal RNA gene from the first isolate was amplified and sequenced. The sequence obtained showed 99% identity with M. leachii. A PCR was developed to amplify a specific fragment of the 16S-23S ITS region corresponding to M. leachii, which allowed to identify the isolates associated with disease in calves.
Assuntos
Doenças dos Bovinos/microbiologia , Indústria de Laticínios , Infecções por Mycoplasma/veterinária , Mycoplasma/isolamento & purificação , Animais , Argentina , Bovinos , Infecções por Mycoplasma/microbiologiaRESUMO
Fecal specimens from 432 pre-weaned calves younger than 35 days were collected over a 2-year period (2010-2012) from 74 dairy cattle farms in the central area of Colombia. These samples were microscopically examined for the presence of Cryptosporidium oocysts, and positive specimens were selected for molecular examination. Microscopy revealed that 115 calves (26.6%) from 44 farms (59.5%) tested positive. Oocyst shedding was recorded in calves aged 3-day-old onwards, although the infection rate peaked at 8-14 days (40.7%). Infection rates were higher in diarrheic (52.2%) than in non-diarrheic calves (19.9%) (p < 0.0001, χ2), and infected calves had up to seven times more probability of having diarrhea than non-infected calves. Cryptosporidium species and subtypes were successfully identified in 73 samples from 32 farms. Restriction and sequence analyses of the SSU rRNA gene revealed C. parvum in all but two isolates identified as Cryptosporidium bovis. Sequence analyses of the 60-KDa glycoprotein (gp60) gene revealed eight subtypes within the IIa family. An unusual subtype (IIaA18G5R1) was the most prevalent and widely distributed (more than 66% specimens and 68% farms) while the subtype most frequently reported in cattle worldwide (IIaA15G2R1) was found in less than 13% of specimens and 16% farms. The remaining subtypes (IIaA16G2R1, IIaA17G4R1, IIaA20G5R1, IIaA19G6R1, IIaA20G6R1, and IIaA20G7R1) were restricted to 1-3 farms. This is the first large-sample size study of Cryptosporidium species and subtypes in Colombia and demonstrates the genetic uniqueness of this protozoan in cattle farms in this geographical area.
Assuntos
Doenças dos Bovinos/parasitologia , Criptosporidiose/epidemiologia , Cryptosporidium parvum/isolamento & purificação , Diarreia/veterinária , Oocistos/genética , Animais , Bovinos , Colômbia/epidemiologia , Criptosporidiose/parasitologia , Cryptosporidium parvum/classificação , Cryptosporidium parvum/genética , Indústria de Laticínios , Diarreia/parasitologia , Fazendas , Fezes/parasitologia , Oocistos/classificação , Oocistos/isolamento & purificação , PrevalênciaRESUMO
The first phase of life of dairy calves has elevated mortality indices linked with low immunity and sanitary challenges, mainly bacterial infections are involved in the pathogenesis of diarrhea, the leading cause of death. Also, other important problem is the nutritional deficiencies, such as the mineral deficiency. Thus, the aim of this study was to evaluate whether an intramuscular mineral supplementation based on selenium, copper, potassium, magnesium and phosphorus possess beneficial effects on health of dairy calves. For this, ten calves were divided in two groups: the group A was supplemented with injectable mineral, while the group B was used as control group (without mineral supplementation). The mineral complex was administrated via intramuscularly at dose of 3 mL/animal on days 2 and 14 post-birth. The total blood was collected on days 2, 10, 20 and 30 of life of animals in order to analyze the antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)), blood count and seric biochemistry linked with proteic, lipid and carbohydrate metabolism. Feces samples were also collected on days 10, 20 and 30 of life of animals to perform the total bacterial count, parasitological exam and fecal consistency score. Moreover, the weight and corporal temperature were also evaluated. The mineral supplementation presented beneficial properties to calves from birth to the 30th of life through the increase on activity of antioxidant enzymes, improvement of immunity, and avoiding problems linked with diarrhea and anemia, can be considered an interesting approach to prevent these alterations linked with high mortality in the period of life.