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The aim of this study was to investigate the vertical transfer of microbiota from dams to the offspring. We studied a pair of 20 dams and its offspring. Maternal sources (colostrum, feces and vaginal secretion) and newborn fecal samples were analyzed using 16S rDNA amplicon sequencing on days 1, 3, 7, 14 and 28. Overall, newborns were maintained healthy and did not receive antimicrobial therapy. The Source Tracker analysis indicated that the newborn fecal microbiota was similar to colostrum and vaginal secretion from day 1 up to 7. However, an unknown source (probably from the environment) showed a gradual increase in its similarity with fecal samples from calves measured from day 3 to 28. The most abundant bacteria groups on meconium (day 1) and calf fecal samples on day 3 were Escherichia-Shigella and Clostridium, respectively. On day 7, the predominant genus were Bifidobacterium and Lactobacillus, while Fusobacterium was the most abundant genus on day 14, coinciding with the diarrhea peak. Faecalibacterium showed a gradual increase throughout the neonatal period. Maternal sources contribute to the neonatal microbiota, however other unknown sources (probably environment) had a strong influence on development of the gut microbiota later in the neonate period.

The transition period in dairy cows is marked by metabolic, oxidative, and immune challenges that increase susceptibility to periparturient diseases. Injectable mineral supplementation (IMS) has been proposed to support immunometabolic adaptation by enhancing antioxidant capacity and immune function, with consistent associations with improved health outcomes but variable effects on production. Therefore, this study evaluated the effects of repeated intramuscular multi-mineral supplementation during the transition period on health, metabolic stress, immune status, and productive performance in Holstein cows. Supplementation was associated with lower odds of subclinical hypocalcemia on day 4 postpartum in primiparous cows (p = 0.02) and overall for persistent subclinical hypocalcemia (p = 0.03). Multiparous cows (p = 0.04) and the overall population (p = 0.01) showed consistent effects on metritis following IMS. Supplemented cows had improved metabolic and uterine health indicators without affecting energy metabolism-related disorders. Although no differences were detected for major postpartum health disorders, its main benefits may involve immune competence, oxidative regulation, and physiological resilience rather than energy balance.

Abstract Background Lung auscultation is a common method for the routine diagnosis of calf bronchopneumonia. However, its repeatability among operators has been criticized. Objective Determine agreement among veterinarians for specific lung sounds after a short tutorial to standardize the definition of lung sounds. Animals Forty lung sounds from a larger dataset collected at 4 veal calf farms that housed 495–815 animals were submitted online to 10 different veterinarians. Methods After a short tutorial on lung sound auscultation, the raters were asked to detect the presence of any abnormal sounds and to differentiate among wheezes, crackles, and bronchial sounds. Raw percentage of agreement (PA), Gwet's agreement coefficient type 1 (AC1), Krippendorff's alpha (Ka), and Fleiss kappa (KFleiss) were chosen as agreement indicators in the absence of a gold standard indicator to assess agreement. The different indicators were interpreted based on a priori reported benchmarks. Results The agreements were fair to good for almost all lung sound indicators. For the presence of any abnormal lung sound, the reported agreements (95% confidence intervals [CI]) were 0.781 (0.716–0.845), 0.646 (0.514–0.777), 0.403 (0.351–0.455), and 0.293 (0.137–0.493) for PA, AC1, Ka, and KFleiss, respectively. The same indicators were 0.769 (0.694–0.845), 0.615 (0.446–0.784), 0.426 (0.378–0.475), and 0.425 (0.293–0.563) for wheezes, 0.754 (0.685–0.823), 0.643 (0.503–0.782), 0.21 (0.146–0.275), and 0.208 (0.097–0.327) for crackles, and 0.636 (0.571–0.701), 0.345 (0.179–0.512), 0.182 (0.131–0.232), and 0.18 (0.081–0.279) for bronchial sound detections, respectively. Conclusion and Clinical Importance Agreement among raters auscultating calf respiratory sounds was higher than previously reported. However, improvement is still possible to increase auscultation agreement.

The aim of this study was to evaluate secondary clinical disease, milk production efficiency and reproductive performance of heifers and cows persistently infected (PI) with bovine viral diarrhea virus type 2 (BVDV type 2). PI animals (n = 25) were identified using an antigen capture ELISA of ear notch samples. They were distributed into three age groups: ≤ 12 (n = 8), 13 to 24 (n = 6) and 25 to 34 (n = 11) months old. A control group of BVDV antigen ELISA negative female cattle that were age matched to the PI animals was utilized from the same herd. The PI group had a 1.29 higher odds ratio for diarrhea than controls (p = 0.001, IC95% = 1.032–1.623) and 1.615 greater chance of developing bovine respiratory disease (BRD) (p = 0.012, IC95% = 1.155–2.259). The age at first insemination (p = 0.012) and number of insemination attempts required to establish the first pregnancy (p = 0.016) were both higher for PI than controls. Milk production was higher for control cows than PI cows during most of the sampling periods. Somatic cell counts (SCC) were higher in PI cows than the controls at all sampling points across lactation (p ≤ 0.042). PI cattle had a higher incidence of disease, produced less milk, a higher SCC, and poorer reproductive performance than control cattle in this study.

Background Neonatal calf diarrhea (NCD) is the leading cause of calf morbidity and mortality in beef cattle. Cow’s vaccination in last stage of pregnancy is one of the most important measures to mitigate the risk of NCD outbreaks. The aim of this study was to evaluate the efficacy of prepartum single dose vaccination against NCD, especially Bovine Rotavirus type A (BoRVA) and Bovine Coronavirus (BCoV), in Nelore dams and offspring. A total of 117 pregnant cows ( n  = 81) and heifers ( n  = 36) were distributed in two groups, vaccinated (VAC: cows = 40; heifers = 19) and non-vaccinated (NVAC: cows = 41; heifers = 17). Vaccination occurred between 60 to 50 days before the expected calving date with a single dose of a water-in-oil (W/O) vaccine, and NVAC group received a dose of saline solution 0.9%. Blood samples were collected before vaccination and 30 days after to evaluate the antibody (Ab) response. Specific IgG1 Abs against BoRVA and BCoV were measured by using an Enzyme Linked Immuno Sorbent Assay (ELISA). Calves’ births were monitored, and the transference of passive immunity was evaluated. Diarrhea was monitored in the first 30 days of age, and fecal samples were collected for identification of the etiological agent. Results Higher titers of IgG1 Ab against BoRVA and BCoV was observed in the VAC group than NVAC group in the cow ( P  < 0.0001) and total dams categories ( P  < 0.0001). The titer of specific IgG1 Abs in the calves’ serum reflected the dams response, observing higher IgG1 Ab titers for BoRVA ( P  < 0.0016) and BCoV ( P  < 0.0095) in the offspring born to VAC cows and higher IgG1 Ab titers for BoRVA( P  < 0.0171) and BCoV ( P  < 0.0200) in the offspring born to VAC total dams. The general incidence of diarrhea observed was 18.6% (11/59) and 29.3% (17/58) in the calves born to the VAC and NVAC group, respectively. Conclusions Prepartum vaccination with a single dose of the vaccine tested increased the titers of IgG1 Ab against BCoV and BoRVA, and it could be used as a preventive strategy to decrease the NCD occurrence in Nelore calves.

This study evaluated the vaccine-induced serological response after administering four commercial formulations containing Bovine Viral Diarrhea Virus (BVDV) type-1, BVDV-2, and Bovine Herpesvirus type 1 (BoHV-1) to young heifers with circulating maternal antibody titers. The study also determined the anamnestic response to vaccinations after the complete metabolization of maternal antibodies when the calves reached six months. Eighty-seven Holstein heifers were selected and randomly distributed into four experimental groups based on the vaccine administered. The four vaccine-based experimental groups were as follows: vaccine A (n = 22), vaccine B (n = 22), vaccine C (n = 24), and vaccine D (n = 19), given on the 60th, 90th, and 180th day of life, respectively. Virus-neutralization (VN) tests were performed at baseline (day 60) and 30 days after administering the second (day 120) and third doses (day 210). We analyzed the effect of vaccine group (P ≤ 0.001), day of vaccination (P ≤ 0.001), and group versus vaccine day interaction (P ≤ 0.001) for antibody titers produced against BVDV-1, BVDV-2, and BoHV-1 using the PROC MIXED method (Statistical Analysis System -SAS 9.4). Antibody titers against BVDV-1, BVDV-2, and BoHV-1 were similar at baseline and on day 60 of life. The mean antibody titers were constant and persisted against BVDV-1 in heifers immunized with vaccines A and C. Heifers immunized with vaccine A alone had a similar effect against BVDV-2. Regarding BoHV-1, the antibody titers decreased between days 60 and 210 in groups B, C, and D. The antibody titer for heifers in group A also decreased between days 60 and day 120, and an intense increase in titers was observed on day 210. After being immunized with formulations B, C, and D, the frequency of animals with titers above protective levels for BVDV-1, BVDV-2, and BoHV-1 was very low or null. Indicators of anamnestic response were observed in heifers vaccinated with formulation A only. Therefore, it can be concluded that passive immunity negatively interferes with antibody production after vaccination. RESUMO: O objetivo desse estudo foi avaliar a resposta sorológica induzida após vacinação com quatro formulações comerciais contendo o BVDV-1, BVDV-2 e BoHV-1 em novilhas jovens com títulos de anticorpos maternos circulantes, assim como analisar uma possível resposta anamnéstica em vacinações, após a completa metabolização dos anticorpos maternais aos seis meses de idade. Foram selecionadas 87 novilhas Holandesas, distribuídas aleatoriamente em quatro grupos experimentais de acordo com as vacinas: vacina A (n = 22), vacina B (n = 22), vacina C (n = 24) e vacina D (n = 19), aplicadas aos dias 60, 90 e 180 de vida. Testes de vírus-neutralização (VN) foram realizados no momento basal (D60) e 30 dias após a aplicação da 2ª dose (D120) e 3ª dose (D210). Observou-se efeito do grupo (P ≤ 0,001), dia da vacinação (P ≤ 0,001), e interação grupo versus dia (P ≤ 0,001) para os títulos de anticorpos produzidos contra o BVDV-1, BVDV-2 e BoHV-1, por meio do comando PROC MIXED (Statistical Analysis System, versão 9,4). Os títulos de anticorpos contra o BVDV-1, BVDV-2 e BoHV-1 eram semelhantes no momento basal aos 60 dias de vida. Os títulos médios de anticorpos foram constantes e persistentes contra o BVDV-1 nas novilhas imunizadas com as vacinas A e C, porém apenas a vacina A teve este mesmo perfil contra o BVDV-2. Em relação ao BoHV-1, os grupos B, C e D apresentaram queda nos títulos de anticorpos do D60 ao D210, enquanto as novilhas do grupo A apresentaram queda do D60 ao D120, com aumento intenso dos títulos no D210. A frequência de animais com títulos acima dos protetores contra o BVDV-1, BVDV-2 e BoHV-1 foram muito baixos ou nulos após as vacinações nos animais imunizados com as formulações B, C e D. Sugere-se que a imunidade passiva interferiu negativamente na indução de anticorpos pelas vacinas, observando-se indicadores de resposta anamnéstica apenas para as novilhas vacinadas com a formulação A.

This study aimed to examine the effects of selenium (Se) and vitamin E (vitE) supplementation on blood cell counts and blood metabolite concentrations in goats and their kids. Fifteen Saanen goats (average age 6 years of age; average initial body weight of 70 ± 10 kg) and 21 ½ Saanen × ½ Pardo Alpine crossbred goat kids (average body weight of 3.70 ± 0.64 kg) were used. Animals were distributed in a completely randomized design with five replicates per diet for mother goats and seven for goat kids and randomly assigned into three groups in the following diets: CON, control basal diet; Se, inclusion of 3.2 mg of Se/kg DM; SevitE, inclusion of 3.2 mg Se/kg DM and 1145 IU/day vitE/kg DM. Effects of time were observed on red blood cells, hemoglobin, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin in goats and goat kids. Effects of time were observed on differential counts of leucocytes, lymphocytes, and monocytes in goat kids. Interaction was observed for high-density lipoprotein and total protein in goats and for triglycerides, beta-hydroxybutyrate (BHBA), and gamma-glutamyltransferase (GGT) in goat kids. Effects of time were observed on low-density lipoprotein, triglycerides, glucose, lactate, BHBA, non-esterified fatty acids (NEFA), creatinine, aspartate-aminotransferase, and GGT in goats and all blood metabolites in goat kids. Selenium, vitE, or association in the evaluated levels are not sufficient to change blood cell counts when supplied in diets for goats or goat kids. However, the effect of time or interaction between time and diets change the blood metabolite concentrations in the animals.

Bovine viral diarrhea virus (BVDV) is a productive and reproductive virus with a high global economic impact on dairy production systems. We investigated the prevalence of BVDV at the herd and individual levels in most dairy-producing regions of Brazil. The frequency of BVDV at the herd level was investigated using quantitative reverse transcription polymerase chain reaction (RT-qPCR) in bulk milk tanks monitored at 289 dairy farms between August 2020 and January 2022. Among these farms, 68 production systems were selected to investigate the prevalence of persistently infected (PI) animals using two antigen-enzyme-linked immunosorbent assays (Ag-ELISAs), at 21-d intervals, from ear-notch samples. In total, 2,902 RT-qPCR and 23,466 Ag-ELISAs were performed. At the herd level, 23.87% (69/289) of dairy farms were considered infected, presenting at least one qPCR test positive. At the individual level, 41.2% (28/68) of the subgroup of selected farms had at least one animal positive in the Ag-ELISA test. Association between tests allowed the classification of farms into the following four categories: level 0, negative for both tests (41.2%, 28/68); level 1, RT-qPCR positive and Ag-ELISA negative (17.6%, 12/68); level 2, RT-qPCR negative and Ag-ELISA positive (13.2%, 9/68); and level 3, positive for both tests (27.9%, 19/68). Multiple correspondence analysis (MCA) suggested a possible association between BVDV positivity and large farms, average daily milk production (herd), breed, and somatic cell counts. The confinement and intensification of animals from different categories, and use of artificial bedding are associated with BVDV infection. Using waste or bulk tank milk to fed calves was also a risk factor for BVDV positivity in RT-qPCR and Ag-ELISA. Despite the use of reproductive vaccines by most producers, their use seems to be associated with BVDV-positive farms. This study presented the epidemiological frequencies of BVDV at the individual and herd levels in the Campos Gerais Paranaense region. The region ranks among the top milk-producing areas in Brazil. Additionally, the association between BVDV tests and farm characteristics indicated the farm risk for BVDV and guides specific control programs. RESUMO: O vírus da diarreia viral bovina (BVDV) é um vírus que afeta a produção e reprodução com alto impacto econômico global nos sistemas de produção de leite. Nosso objetivo foi investigar a prevalência do BVDV em rebanhos e indivíduos na região de maior produção de leite do Brasil. A frequência do BVDV nos rebanhos foi investigada usando reação em cadeia da polimerase com transcrição reversa quantitativa (RT-qPCR) em tanques de leite em 289 fazendas leiteiras, monitoradas entre agosto de 2020 e janeiro de 2022. Dentre esses rebanhos, 68 sistemas de produção foram selecionados para investigar a prevalência de animais persistentemente infectados (PI) usando dois testes imunoenzimáticos para a detecção do antígeno (Ag-ELISAs), em intervalos de 21 dias, a partir de amostras de tecido auricular. No total, foram realizados 2.902 RT-qPCR e 23.466 Ag-ELISAs. Na investigação dos rebanhos, 23,9% (69/289) das propriedades leiteiras foram consideradas infectadas, apresentando pelo menos um teste qPCR positivo. Na pesquisa de animais Pis, 41,2% (28/68) das fazendas selecionadas tiveram pelo menos um animal positivo no teste Ag-ELISA. A associação entre os testes permitiu classificar as propriedades em quatro categorias: nível 0, negativo para ambos os testes (41,2%, 28/68); nível 1, RT-qPCR positivo e Ag-ELISA negativo (17,6%, 12/68); nível 2, RT-qPCR negativo e Ag-ELISA positivo (13,23%, 9/68); e nível 3, positivo para ambos os testes (27,9%, 19/68). A análise de correspondência múltipla (MCA) sugeriu associação entre positividade para BVDV e grandes propriedades, produção média diária de leite do rebanho, raça e contagem de células somáticas. O confinamento e a intensificação de animais de diferentes categorias e o uso de camas artificiais estão associados à infecção pelo BVDV. O uso de leite residual ou a granel também foi um fator de risco para positividade para BVDV em RT-qPCR e Ag-ELISA. Apesar da utilização de vacinas reprodutivas pela maioria dos produtores, a sua utilização parece estar associada a explorações positivas para BVDV. Este estudo apresenta as frequências epidemiológicas do BVDV nos rebanhos e indivíduos de rebanhos da região dos Campos Gerais Paranaense. A região está entre as principais áreas produtoras de leite do Brasil. Além disso, a associação entre os testes de BVDV e as características da fazenda indica o risco da fazenda para o BVDV e orienta programas de controle específicos.

This study aimed to evaluate the effect of bovine leukemia virus (BLV) on the systemic profile of naturally infected dairy heifers during the transition period. Pregnant Holstein and Jersey heifers (n=24) were distributed in pairs into two experimental groups: (BLV+) and (BLV-). Animals in the BLV+ group were divided into two subgroups based on the median BLV proviral load (high and low). The animals were then assessed at weeks -3, -2, -1, calving time (0), +1, +2, and +3. Blood samples were obtained for hematological and biochemical analyses, as well as haptoglobin measurements. Farm BLV screening revealed a herd BLV prevalence of 57.25% and heifer BLV prevalence of 38.7%. Mean corpuscular hemoglobin concentration was the only hematological variable for which group interaction was observed, with BLV+ cattle having higher values (33.29 ± 3.39%) than BLV- cattle (31.08 ± 2.31%). Aspartate aminotransferase activity was higher in the BLV+ heifers. The BLV+ group had greater incidence of inflammation (haptoglobin ≥ 2.0 mg/dL). Fibrinogen concentrations were also higher at weeks 0 and +1 in BLV+ heifers than in BLV- heifers. A high proviral load affected total leukocyte and lymphocyte count; however, this profile was not observed in the low proviral load and paired BLV- heifers. To our knowledge, this is the first study to report the impact of BLV infection on the health of dairy heifers during the transition period, demonstrating the effect of proviral load on white blood cell changes and early inflammation in infected animals. RESUMO: O objetivo deste estudo foi avaliar o efeito do vírus da Leucose Bovina (BLV - BovineLeukosis Virus) sobre o perfil sistêmico em vacas primíparas no período de transição. Novilhas prenhas das raças Holandesa e Jersey (n=24) foram distribuídas em pares em dois grupos experimentais: (BLV+) e (BLV-). Os animais BLV+ foram classificados em subgrupos com alta e baixa carga proviral, de acordo com a mediana dos valores obtidos. Os animais foram avaliados nas semanas -3, -2, -1, parto (0), +1, +2 e +3. Amostras sanguíneas foram obtidas para análises hematológicas e bioquímicas, além da dosagem de haptoglobina. Na fase de triagem observou-se soroprevalência de 57,25% e 38.7%, respectivamente no rebanho e na categoria novilhas (38,7%). Em relação ao eritrograma, a concentração de hemoglobina corpuscular média (CHCM) foi a única variável que apresentou interação grupo*tempo, observando-se maiores valores no grupo BLV+ (BLV+ = 33,29 ± 3,39%; BLV- = 31,08 ± 2,31%). BLV teve efeito sobre a atividade da enzima aspartato aminotransferase (AST), com maiores valores no grupo BLV+. Os animais BLV+ apresentaram 4,96 mais chances de inflamação (haptoglobina ≥ 2,0 mg/dL). A concentração do fibrinogênio também foi maior no grupo BLV+ no parto e semana +1 pós-parto. O efeito da carga proviral sobre os leucócitos totais e número absoluto de linfócitos foi detectado. No nosso conhecimento, este é o primeiro estudo reportando o efeito do BLV sobre a saúde de vacas primíparas no período de transição, e a dependência da carga proviral sobre o perfil leucocitário e o perfil pró-inflamatório dos animais BLV+.

This study determined the association between biosecurity practices and the status of bovine viral diarrhea virus (BVDV) in dairy production systems. Approximately 280 herds were screened for BVDV virus detection. Following the screening, 68 herds were selected to identify individual BVDV PI animals using an ear notch biopsy and ELISA-antigen. All offspring of the last generation were tested, and the maternal lineage of positive cases was examined. A questionnaire on BVDV biological risk assessment was completed. A multiple correspondence analysis (MCA) was conducted to determine the association between herds with or without BVDV circulation and biosecurity practices. The MCA revealed that farms with virus circulation lacked knowledge about the disease and wrongly perceived their herds as protected, while farms without virus circulation were aware of the disease but considered their herds unprotected. Vaccination practices differed between positive and negative herds, with positive herds using vaccines only for reproductive diseases and negative herds vaccinating for respiratory and reproductive issues. Biosecurity practices such as frequent visitation, contact between animals of different ages, and annual introduction of new animals were linked to viral circulation, while virus-free herds implemented measures like controlled visitation, no contact between different age groups, and quarantine. Lastly, herds with virus circulation acquired pregnant females without prior testing. This study emphasized the crucial role of biosecurity practices in controlling BVDV in dairy herds. It highlighted the sharper risk perception and better application of biosecurity practices in negative herds compared to BVDV-positive herds. RESUMO: Esta pesquisa teve como objetivo associar as práticas de biosseguridade com a circulação do vírus BVDV em sistemas de produção leiteiros. Inicialmente, 270-290 sistemas foram selecionados para detecção do vírus entre janeiro de 2020 e janeiro de 2023 por meio da técnica de Reação em Cadeia da Polimerase em Tempo Real (RT-qPCR em tempo real). Após essa etapa, 68 rebanhos foram selecionados para identificação de animais persistentemente infectados (PI) por meio da análise individual do fragmento auricular usando o método ELISA-antígeno. Todos os animais nascidos na última geração, fêmeas que deram à luz bezerros machos ou natimortos, foram testados incluindo a pesquisa na geração de mães e avós maternas em casos positivos. Um questionário de análise de risco biológico para o BVDV foi aplicado a esse grupo de fazendas. Para identificar associações entre rebanhos com ou sem circulação do BVDV e práticas de biosseguridade, foi usada a análise de correspondência múltipla (MCA). A análise mostrou associação entre a falta de conhecimento sobre a doença e a percepção de que o rebanho está protegido contra o BVDV em fazendas com circulação do vírus. Os rebanhos positivos para Diarreia Viral Bovina reportaram o uso vacinas apenas para doenças reprodutivas, enquanto os rebanhos negativos reportaram o uso vacinas para problemas respiratórios e reprodutivos, sugerindo possíveis diferenças nos protocolos de vacinação e na eficácia das vacinas no Brasil. Práticas de biosseguridade como visitas frequentes, contato entre animais de diferentes idades e a introdução anual de novos animais, foram associadas à circulação viral, enquanto os rebanhos livres de vírus adotaram medidas como políticas de visitação e controle, ausência de contato entre os bovinos de diferentes idades e quarentena. Além disso, os sistemas de produção positivos adquiriram fêmeas prenhes sem testar o animal previamente. Assim, este estudo destaca aspectos essenciais para o controle do vírus da Diarreia Viral Bovina em rebanhos leiteiros, identificando que gestores de rebanhos negativos possuem maior percepção de risco associada à implementação de práticas de biosseguridade, em contraste comos rebanhos positivos para o BVDV.