Search Results (741)

Escherichia coli, Clostridium perfringens and Cryptosporidium are common diarrhea-related pathogens in dairy calves, posing considerable economic losses to animal husbandry and threatening public health. A previous study in our lab found the frequent occurrence of Escherichia coli virulence genes (eaeA, stx1 and stx2), Clostridium perfringens cpa and Cryptosporidium in diarrheic dairy calves in Ningxia Hui Autonomous Region, China. The present study aimed to develop a multiplex PCR for simultaneous detection of these virulence genes and Cryptosporidium in diarrheic dairy calves. The multiplex PCR demonstrated sensitivities of 2060 copies, 18200 copies, 1300 copies, 1990 copies and 974 copies for stx1, stx2, eaeA, cpa and 18S rRNA, respectively. Moreover, the method showed no cross-reactivity with Giardia duodenalis, Enterocytozoon bieneusi, Eimeria, Haemonchus contortus, Oesophagostomum, Moniezia, Salmonella, Proteus mirabilis and Staphylococcus aureus. Further application of the multiplex PCR in 20 clinical faecal samples from diarrheic dairy calves found that the positive rates of the multiplex PCR assay were 55% (11/20), 50% (10/20), 60% (12/20), 45% (9/20) and 25% (5/20) for stx1, stx2, eaeA, cpa and 18S rRNA, respectively, which were not significantly lower than those of the conventional PCR targeting stx1 (60%, 12/20) and eaeA (65%, 13/20), but higher than those of the reported PCR targeting stx2 (45%, 9/20) and cpa (40%, 8/20), and were consistent with those of the reported nested PCR targeting 18S rRNA (25%, 5/20). Taken together, the present study preliminarily developed a multiplex PCR assay for the rapid detection of selected E. coli virulence genes, C. perfringens cpa and Cryptosporidium 18S rRNA in dairy calves, which could provide basic data and technical support for the diagnosis and prevention of calf diarrhea. However, more samples from divergent clinical settings are needed to validate the assay in the diagnosis of selected E. coli virulence genes, C. perfringens cpa and Cryptosporidium 18S rRNA in future studies. Full article

Early-life nutrition is critical for the development and health of dairy calves, necessitating alternatives to in-feed antibiotics. This study investigated whether dietary glycerol monolaurate (GML) enhances growth performance, reduces diarrhea incidence, improves systemic antioxidant and immune status, and modulates hepatic immunometabolic function in calves. Twenty-four Holstein bull calves (7 ± 0.5 d of age) were randomly assigned by body weight and age to a control group or a GML-supplemented group, both fed milk replacer with starter feed provided throughout the 45-day trial. Calves in the GML group received GML at a dosage of 100 mg/kg of body weight, mixed into the milk replacer prior to feeding. Calves in the GML group had significantly greater final body weight, average daily gain, and starter intake during the latter period (d 23–45) compared with the control group. GML supplementation also significantly reduced the incidence of diarrhea and fever, alongside lower fecal scores and fewer antibiotic treatments. Plasma analysis revealed enhanced antioxidant capacity, as indicated by increased total antioxidant capacity and glutathione peroxidase, along with an improved immune profile characterized by elevated immunoglobulin G and reduced interleukin-2. Transcriptomic analysis of the liver showed that GML upregulated genes and pathways related to innate antiviral immunity, such as radical S-adenosyl methionine domain containing 2, interferon-stimulated gene 15, and MX dynamin like GTPase 1. Lipidomics further indicated that GML induced a targeted remodeling of hepatic lipids, including increased diacylglycerols and triacylglycerols and decreased specific phospholipids and sphingolipids, suggesting a metabolic shift supportive of immune activation and inflammatory control. In conclusion, dietary GML enhances growth and health in suckling calves, which is mediated through a coordinated immunometabolic reprogramming in the liver. GML represents a promising functional fat additive for sustainable calf rearing. Full article

Dairy production in Indonesia relies on two contrasting calf-rearing systems: concentrate-driven commercial dairy systems (CDS) and smallholder farms (SH). As these systems differ in feeding practices, they may influence gut development in calves. This study examined how farm management affects the fecal microbiota and metabolites in healthy and diarrhea post-weaning calves. Fecal samples were collected from 11 and 14 calves from CDS and SH facilities, respectively. Gut bacterial communities were analyzed using 16S rRNA gene amplicon sequencing, and metabolites were characterized using untargeted gas chromatography–mass spectrometry (GC-MS). Microbial diversity, metabolite profiles, and correlation networks were compared between the farm types and diarrhea status. Our results showed that farm management strongly shaped microbial community structure and metabolic outputs, but did not alter microbial richness. Although diarrhea is typically associated with reduced microbial richness, it did not affect the microbial community structure, suggesting that it primarily impacted microbial function, particularly the metabolic environment. Correlation network analysis revealed stronger linkages between microbes and metabolites in SH calves, especially under healthy conditions. Overall, these findings indicate that dietary structure is a key determinant of fermentation stability, with CDS calves showing greater metabolic instability. In contrast, SH calves maintain a more resilient, fiber-driven functional state. Full article

The aim of this study was to identify the main causes of neonatal mortality in dairy calves (0–30 days of age) in Poland and to assess how infectious factors and management practices influenced the pattern of mortality. A retrospective analysis was performed on 498 calves from 312 herds between 2018 and 2024. The protocol included necropsy, enteropathogen diagnostics (PCR and ELISA), and analysis of herd management questionnaires. The leading causes of death were chronic diarrhea (42.4%), acute diarrhea (25.3%), and septicemia (10.8%). Calves that died from septicemia were the youngest (mean age 7.7 days), whereas those that died from chronic diarrhea were the oldest (20.3 days; p < 0.001). Lack of dam vaccination was associated with a higher occurrence of acute diarrhea (RR = 2.04) and septicemia (RR = 2.01) within the necropsied calf population. Inappropriate colostrum management was also associated with a higher occurrence of septicemia (RR = 1.99). Despite widespread antimicrobial use (>80%), intensive fluid therapy was used rarely (<7% in diarrheal cases). ETEC, rotavirus, and coronavirus were detected significantly more frequently in acute diarrhea, whereas Cryptosporidium parvum (C. parvum) was significantly more frequent in chronic diarrhea. Antimicrobials were used extensively, while intensive fluid therapy for diarrhea was implemented infrequently and inadequately relative to disease severity. This study makes an important contribution to the understanding of calf mortality in dairy herds by combining comprehensive postmortem diagnostics with pathogen detection (PCR and ELISA) and the assessment of management practices, thereby providing a holistic perspective on the problem. The analysis of 498 calves from 312 farms over a 7-year period offers an unprecedented and representative picture of the situation in Poland, one of Europe’s major milk producers. These results emphasize the crucial importance of proper colostrum management and vaccination, while also indicating a clear and urgent need to expand the use of fluid therapy in calves requiring treatment. The results identify not only the dominant pathogens and differences in disease course, but also management factors with direct implications for animal welfare and preventive strategies in dairy production. Full article

Vaccinia virus strain Cantagalo (CTGV) causes a pustular disease in dairy cows and milkers in Brazil. Outbreaks in several states have been frequently reported, but the full genome sequence and genomic analysis of isolates from the Northeast region have never been described. Here, we report CTGV outbreaks in two Northeastern states, affecting milkers, lactating cows, and suckling calves. The farms were located in the main dairy belt of Pernambuco, in the Borborema Plateau, and in a rural region of Bahia. Of the 12 samples that tested positive for CTGV, five had their genomes fully sequenced. They cluster with CTGV isolates from Goiás (Midwest region, 2022) and São Paulo (Southeast region, 2023) but diverge from isolates from the Southeast in the early 2000s. Two clinical isolates have accumulated greater genetic variability and segregate separately from the other three isolates from the Northeast, showing evidence of potential recombination events with the FAI-01 isolate from the Midwest region (2022). We also detected Parapoxvirus and CTGV coinfection in some animals. These findings likely suggest different episodes of virus introduction in these states. The spread of CTGV raises concerns about the potential impact on local economic activities and underscores the importance of avoiding raw milk consumption. Full article

Bovine rotavirus (BRV) is a major pathogen causing diarrhea in neonatal dairy calves, yet its impact on the gut microbiome and host metabolism remains incompletely understood. This study integrated 16S rRNA gene sequencing and untargeted metabolomics to characterize the fecal microbial and metabolic profiles of BRV-infected diarrheic calves compared to healthy controls. Fecal samples were collected from 16 Holstein calves (<30 days old), equally divided into a BRV-infected group (confirmed by RT-qPCR) and a healthy control group. Alpha diversity analysis revealed a significant reduction in microbial richness (Chao1, p = 0.012) in the BRV group. Beta diversity (Jaccard distance) showed distinct clustering between groups (PERMANOVA, p < 0.05). Linear discriminant analysis effect size (LEfSe) identified a significant enrichment of Escherichia (Proteobacteria) and Enterococcus (Firmicutes) in BRV calves, whereas healthy controls were enriched in Blautia and Faecalibacterium (both Firmicutes, with Faecalibacterium also commonly associated with healthy gut communities). Metabolomic analysis via UHPLC-MS/MS demonstrated a clear separation of metabolic profiles. BRV infection was associated with significant alterations in lipid metabolism pathways, notably elevated levels of lysophosphatidylcholines (LPCs) and lysophosphatidylethanolamines (LPEs). Integrated Spearman correlation analysis revealed extensive and significant associations (|ρ| > 0.6, FDR-adjusted p < 0.05) between differential bacterial genera (e.g., Enterococcus, Escherichia) and differential metabolites (e.g., glycerolipids, amino acid derivatives), suggesting a close linkage between gut microbial dysbiosis and metabolic remodeling during BRV infection. These findings provide a multi-omics perspective on the interplay between the gut microbiota and host metabolism in BRV-induced diarrhea, offering potential insights for developing microbiota-based diagnostic or therapeutic strategies. Full article

The Moon is at the centre of many popular beliefs, including the notion that the number of parturitions increases during Full Moon days, a belief widely held among breeders to anticipate calving periods. However, this association has been rarely explored in dairy cattle farming. This retrospective study was conducted to evaluate the association between the lunar cycles and calving distribution, with particular focus on a potential increase during full-moon nights. Data from 383,926 calvings of Montbéliard breed, recorded between March 2022 and January 2025, mostly in Franche-Comté (98.2%), France, were analyzed using a Generalized Linear Model (GLM). Results revealed a significant association between the lunar cycle and calving distribution. Model-adjusted means were significantly higher than the overall mean during the New Moon and the Last Quarter phases (+2.6%, p < 0.05), and significantly lower during the Full Moon phase (−3.1%, p < 0.01). At the synodic day level, days 21 and 29 presented the highest model-adjusted means (+23.2% and +23.4% above the overall mean, respectively; p < 0.001), while days 4 and 15 presented the lowest (−35.2% and −31.1%, respectively; p < 0.001). Across all seasons, a consistent trend toward increased calving frequency was observed during the New Moon phase, reaching statistical significance only in Spring (+5.7%, p < 0.05). These findings may offer potential implications for veterinarians and breeders, particularly when considering approaches to ensure adequate colostrum intake, which may contribute to improving management of parturition periods. Full article

Background: Lumpy skin disease (LSD) is caused by a Capripoxvirus. Live attenuated vaccines, which are commercially available, could be not safe because of the side effects. The aim of this study was the evaluation of the safety, immunogenicity, and effects on the qualitative and quantitative parameters of milk. The feasibility of identifying vaccinated animals using our inactivated vaccine in dairy cows was analysed. The vaccine was tested in guinea pigs as an immunogenicity predictive model. Methods: LSD virus was propagated on Madin–Darby Bovine Kidney (MDBK) cells, then inactivated and supplemented with keyhole limpet hemocyanin (KLH) protein, obtaining a positive marker vaccine. This was inoculated in guinea pigs and in dairy cows, and animal sera were analysed using enzyme-linked immunosorbent assay (ELISA) and a serum neutralisation (SN) test. Quantitative and qualitative analyses were performed on milk. Results: The vaccine was previously tested for efficacy in vaccinated calves, showing a pronounced reduction in clinical symptoms after challenge. The safety and immunogenicity obtained in calves were also confirmed in dairy cows in this study. In fact, high values of the SN test (1:20 to 1:80) and ELISA (90 and 240 S/P%) were obtained after vaccination. Moreover, high immunogenicity of the vaccine was also assessed in guinea pigs. In addition, the results of the milk analyses did not show any differences between vaccinated and control groups. The KLH was able to elicit an immune response detectable using an ELISA (3.0 and 3.5 optical density values). Finally, our vaccine could be used to reduce LSD symptoms and identify vaccinated animals. Full article

Longevity is a key determinant of economic efficiency and sustainability in dairy cattle production. The study evaluated longevity and lifetime productivity traits in red breed (RB) and Holstein breed (HB) dairy cows in Latvia and assessed the effects of birth year, age at first calving (AFC), and farm size. Data from 279,818 culled and living cows born between 2010 and 2019 were analyzed. The aim of the study was to investigate biological and farm-level factors affecting dairy cow longevity in RB and HB populations. RB and HB cows born between 2010 and 2013 had significantly longer (p < 0.05) total lifespan (LS) and productive life (PL) than cows born in later years; however, they showed lower life day (MPD) and productive life day (MPPD) milk productivity. AFC significantly affected MPD and MPPD. The highest life day productivity in RB cows was observed at AFC of 22.1–24 months, while in HB cows it was observed at <24 months. Significantly longer LS and PL were recorded on farms with fewer than 20 cows, whereas the highest MPD was observed on farms with 101–500 cows in RB and 101–200 cows in HB. Full article

The responsiveness of the stress axis is fundamental for maintaining health and sustaining productive performance; however, the effect of modulating this stress axis with bovine appeasing substance and its effects on biochemical, immunological, oxidative parameters and uterine involution have not been determined, which are the objectives of this experiment. To elucidate these questions, Holstein cows, from the prepartum to lactation period in a cross-ventilation system, received an application of a bovine appeasing substance (treated group) and a 0.9% saline solution (control group) at the time of calving, and blood samples were collected on calving day and on days 3, 7, 14 and 21 postpartum for analysis. Modulation of the stress axis by bovine appeasing substance increased magnesium levels on days 7 and 14 postpartum, with a reduction in fructosamine levels on days 3, 7, 14, and 21 postpartum. A reduction in ferritin levels, an acute-phase protein, and a reduction in interleukin 1 beta and interleukin 6 were also observed, demonstrating an anti-inflammatory effect in cows of the treated group. Creatine kinase activity decreased on day 21 postpartum in cows treated with bovine appeasing substances. An increase in cholinesterase activity on day 7 and a marked decrease on day 21 postpartum in treated cows were observed compared to the control. This was accompanied by a reduction in beta-hydroxybutyrate levels on day 7 and a reduction in reactive oxygen species levels on day 14 in animals of the treated group, indicating modulation of ketogenesis and reduced oxidation through an anti-inflammatory effect. Mean uterine thickness was also affected by the bovine appeasing substance, with a lower mean thickness on day 21 postpartum in treated cows. Modulation of the stress axis by the bovine appeasing substance reduces inflammation, improving energy dynamics and reducing oxidation, thus facilitating tissue repair associated with postpartum uterine involution in dairy cows. Full article

The preweaning period is a critical phase for dairy calves, during which gastrointestinal disorders, particularly diarrhea, remain a major cause of morbidity and antimicrobial use. Astaxanthin, a xanthophyll carotenoid with antioxidant and anti-inflammatory properties, has shown potential to support intestinal health in several animal species, but information in preweaning dairy calves is limited. The objective of this study was to evaluate the effects of astaxanthin supplementation administered through milk replacer on growth performance, clinical health, metabolic profile, and fecal microbiota in preweaning Holstein calves. Twenty-four female Holstein calves (body weight, mean ± SD: 49.51 ± 12.14 kg) were randomly assigned to a control group (CTR; n = 12) or an astaxanthin-supplemented group (TRT; n = 12). Treated calves received 40 mg/d of astaxanthin from week 0 to 4 and 80 mg/d from week 4 to 8. Body weight, feed intake, rectal temperature, and fecal consistency score, fecal color score and clinical scores were recorded throughout the trial. Blood samples were collected in weeks 0 and 8 for metabolic profiling, and fecal samples were collected in weeks 0, 4, and 8 to assess fecal consistency and bacterial populations. Astaxanthin supplementation did not affect body weight, average daily gain, or overall feed intake. However, treated calves exhibited a lower frequency of abnormal fecal consistency scores, indicating reduced diarrhea incidence compared with control calves. Fecal microbiological analysis revealed lower coliform counts in astaxanthin-supplemented calves in weeks 4 and 8, whereas total bacterial counts were greater in week 8. Most blood metabolites were primarily influenced by age-related physiological changes; however, circulating calcium concentrations were greater in treated calves. These results suggest that astaxanthin may represent a promising nutritional strategy to support gastrointestinal health during early life, although larger studies are needed to confirm these findings. Full article

Precision Livestock Farming (PLF) tools are increasingly used in dairy production, but their success depends on farmers’ perceptions, needs and investment capacity. This study explores the current use of digital technologies, satisfaction levels and future expectations among Italian dairy farmers. An online questionnaire with 19 questions collected 53 complete responses between May and November 2025. Most of the farms were free-stall Holstein dairy farms located in the Po Valley and managed by relatively young and well-educated farmers, many of whom had a background in animal production. The adoption of PLF tools was widespread: management software (73.6%), automated total mixed ration (TMR) preparation (66.0%), heat stress mitigation systems (62.3%) and collar sensors (52.8%) were the most adopted technologies. Satisfaction with current tools was high, although installation costs and poor system integration were consistently identified as major constraints. Farmers expressed clear priorities for future devices, particularly early diagnosis of health problems, calving, heat, lameness, and feeding and rumination functions. The results suggest that PLF in Italian dairy systems is moving from the adoption phase to that of consolidation. However, improvements in interoperability, affordability and farmer-centred design remain essential to support a wider and more equitable spread of the technology across the sector. Full article

In order to guarantee sufficient growth, digestive stability, and long-term productivity in dairy heifers, proper nutritional management is crucial both before and after weaning. This case study assesses the impact of dietary modifications on growth performance and digestive parameters in commercial settings and details a field observation of concentrate overload in young Holstein heifers. From 77 to 165 days of age, the body weight (BW), average daily gain (ADG), body condition score (BCS), feed intake, and fecal characteristics of 15 calves were monitored. Infectious and parasitic causes of diarrhea were ruled out by fecal examinations. Ad libitum concentrate feeding resulted in low fecal scores with undigested grain particles and acidic smell, starch intake exceeding requirements, and concentrate intake reaching up to 6 kg as fed head×day. The BCS gradually rose, and ADG peaked at 1.64 kg/day. Forage intake increased, fecal consistency improved, and ADG stabilized after restricting concentrate allowance to 2.5% of BW. These results underline the significance of controlling starch intake and concentrate allowance to avoid excessive growth and digestive disorders in developing dairy heifers, and they support a nutritional basis for the observed digestive imbalance. Full article

Production diseases in dairy cattle impose economic and welfare burdens, yet few studies quantify costs using on-farm cases. This study aimed to estimate costs and lost revenues at the individual-animal level in 10 German dairy farms (average of 592 cows; 9694 kg marketed milk/cow/year; 32.9% culling rate). Each farm was visited for three weeks; diseased cows and calves were examined by a trained veterinarian. Diagnoses, treatments, labour times, and outcomes were recorded, and costs calculated for labour, products, veterinary and orthopaedic services, discarded milk, decreased milk yield, culling, book loss, and reduced carcass value. In total, 1272 single-animal cases were included: 68% were stand-alone diseases, 11% involved multiple diagnoses within one organ system, and 21% affected several organ systems. When several diseases occurred in the same animal, total costs and lost revenues were greater than the sum of stand-alone cases, indicating compounding effects. High-impact conditions included mastitis, claw disorders, left displaced abomasum, and multimorbidity; per-case losses ranged from €43 (digital dermatitis) to >€1200 (left displaced abomasum with complications). Labour and culling-related costs were higher than reported, and productivity losses exceeded treatment costs in many cases. Findings support farm-level decision-making, prevention, and parameterization of future dynamic models. Full article