Search Results (387)

The present study assessed the efficacy of selective dry cow therapy (SDCT) on two commercial Holstein-Friesian farms in the Czech Republic, involving 572 quarter milk samples from 74 cows collected over a two-year period. Quarter samples were taken both at dry-off (n = 296) and post-calving (n = 276) to assess somatic cell count (SCC), cultured microbial results (counts), milk composition, and mastitis incidence. The average SCC at dry-off was 264,000 cells/mL (SD = 650,000) in Farm 1 and 224,000 cells/mL in Farm 2. Mastitis incidence averaged 24.42% and 18.75% in Farms 1 and 2, respectively. Correlation analysis revealed significant associations between pre-dry-off milk parameters and post-calving udder health indicators, including negative correlations between SCC prior to drying-off and lactose content after calving (r = −0.161, p < 0.01). Statistical analyses showed a significant farm effect on cultured microbial occurrence and mastitis occurrence after calving (p < 0.05), as well as a significant influence of lactation number on postpartum mastitis and SCC (p < 0.05). Also, mastitis incidence was significantly higher (9.43%, p < 0.05) in treated quarters. The use of selective non-antibiotic dry cow therapy does not impair udder health and milk quality but helps reduce the risk of antibiotic resistance. Further refinement of diagnostic criteria is needed to optimize treatment decisions and improve herd-level outcomes. Full article

Background/Objectives: The aim of this study was to classify cows with respect to different diets, dry period (DP) lengths, and lactation weeks based on body weight, milk variables, and plasma metabolites measured in early lactation. Methods: Holstein–Friesian cows (n = 95) were randomly assigned to three DP lengths (0, 30, or 60 d; n = 31, 34, and 30) and two early-lactation diets (lipogenic: n = 47; glucogenic: n = 48) in a 3 × 2 factorial design. From 10 d pre-calving to 8 weeks postpartum, cows received experimental diets. An XGBoost model was trained for classification using weekly body weight, milk variables, and plasma metabolites, validated via 1000 repeated hold-out partitions with stratified sampling. Results: Classification performance for lactation week, relative to week 1 in lactation, was good, with an area under the curve (AUC) > 0.9, independent of diet or DP length. The classification for 0 d vs. 60 d DP length was better than that for 0 d vs. 30 d or 30 d vs. 60 d DP length, showing an AUC > 0.8, independent of diet or lactation week. The top features to classify diet were plasma urea and milk fat content. Milk yield and protein content were the important features for classifying lactation weeks regardless of diet, while milk fat content was a critical predictor specific to the glucogenic diet. Conclusions: Our findings demonstrate that milk and plasma features can retrospectively classify management groups in early lactation using machine learning approaches. Full article

This study investigated cow longevity, culling reasons, and risk factors influencing culling in South African Holstein and Jersey dairy herds. Lactation records of 1,150,625 Jersey and 1,534,875 Holstein cows from 1864 herds, recorded through the National Milk Recording Scheme during the period 2000 to 2019, were analyzed. Longevity was calculated as length of productive life and number of completed lactations. Logistic binary regression was conducted to estimate the odds ratios (OR) for culling among different calving seasons, parities, and herd sizes. Holstein cows had mean productive life of 739.33 ± 434.31 days and 2.37 ± 1.08 lactations, while Jersey cows averaged 696.81 ± 415.44 days productive life and 2.47 ± 1.13 lactations. Leading reasons for culling were infertility (37.94 ± 0.48% Holstein; 30.46 ± 0.63% Jersey), mastitis (18.15 ± 0.38% Holstein and 18.16 ± 0.53% Jersey), and low milk yield (11.76 ± 0.32% Holstein and 19.76 ± 0.55% Jersey). Summer calving, third parity, and small herd size had the highest odds of culling. These findings suggest that herd management practices and selection objectives in South Africa should place high emphasis on cow fertility and udder health. Furthermore, cows calving in summer and those in third parity or small herds require particular attention to minimize culling. Such measures may help to reduce involuntary culling rates and thus increase herd profitability as well as dairy industry sustainability. Full article

This study investigated the effects of supplementing whole milk (WM) with sodium butyrate (SB) on the gastrointestinal microbiota of preweaned calves. Twelve newborn Holstein calves (4 days old, 39.21 ± 1.45 kg) were randomly assigned into one of two dietary treatments: (1) WM without SB (CON) and (2) WM supplemented with SB (8.8 g/d; SB). At 74 days of age, all calves were slaughtered to collect ruminal and cecal digesta. Metagenomic analysis was used to characterize the microbial composition, virulence factor genes (VFGs), and antibiotic resistance genes (ARGs). SB supplementation altered the ruminal microbial composition and increased the abundance of beneficial bacteria, including Actinobacteria, Bifidobacterium, and Olsenella (p < 0.05). Although SB did not significantly affect the overall microbial composition or diversity in the cecum (p > 0.05), it promoted the growth of beneficial genera such as Flavonifractor and Subdoligranulum (p < 0.05). Furthermore, SB supplementation did not significantly alter the composition of VFGs or ARGs in either the rumen or the cecum (p > 0.05). However, significant differences in VFGs and ARGs were observed between the rumen and the cecum, with a greater diversity of both VFGs and ARGs detected in the cecum compared to that in the rumen (p < 0.05). In summary, supplementing whole milk with sodium butyrate modulates gastrointestinal health in preweaned calves by favorably shaping the microbial community without significantly altering the antibiotic resistome or virulome. Full article

Disbudding is a common practice on dairy farms, with the hot iron method (HID) widely used, though it causes considerable pain if no analgesia is provided. This study included two experiments. In Experiment 1, an alternative method using policresulen (POD) was evaluated in 24 Holstein calves randomly assigned to either POD or HID at 21 ± 2 days of age. Calves in the POD group received 0.2 mL of 36% policresulen per horn bud, while those in the HID group were fully cauterized. The cornual nerve was blocked with 5 mL of 2% lidocaine in both treatments, and all calves received meloxicam (0.5 mg/kg body weight) for three days post-procedure. Calves treated with POD exhibited fewer pain-related behaviors, such as scratching the horn buds, rubbing against objects, and head shaking, and showed faster horn bud regression. However, 12-month observations revealed that 9 of 12 POD-treated calves showed horn regrowth, indicating limited long-term effectiveness. Experiment 2 assessed consumer perceptions through a questionnaire and video with 236 participants. Participants with farming experience were more familiar with disbudding and preferred HID. In contrast, individuals with less agricultural contact demonstrated a greater willingness to pay for products from farms implementing animal welfare practices, with 76% favoring POD. Overall, participants experienced in agribusiness prioritized technical knowledge and practicality, while others valued animal welfare and were willing to pay higher prices for welfare-friendly practices. Full article

This pilot study evaluated the effects of cannabidiol (CBD) oil supplementation on growth performance, stress biomarkers, and haematological profiles in dairy calves undergoing the weaning transition. Nineteen Holstein calves were divided into two paternal-sibling groups: a CBD-supplemented experimental group (n = 10) and a CON-control group (n = 9). The CBD group received 5 mL/head/day of CBD oil for the first two days (pre-weaning), followed by 10 mL/head/day for three consecutive days post-weaning. Body weight increased significantly over time in both groups (p = 0.000); nevertheless, no significant differences were observed between groups (p = 0.173) or for the group × time interaction (p = 0.929), indicating that CBD did not affect overall growth trajectory. However, a significant group × time interaction (p = 0.006) for average daily gains in the CBD group was observed. Serum cortisol concentrations were significantly lower in CBD-supplemented calves at Day 0 and +2 days, compared to the CON group, indicating a transient anti-stress effect (p = 0.043 for group effect). At +5 days, cortisol levels in the CBD group increased, surpassing control values, though this difference was not significant. A trend-level group × time interaction (p = 0.067) suggested a distinct temporal cortisol response in CBD-treated calves. Immune cell counts (LYM, MON, NEU) showed no significant differences, though monocyte levels trended lower in CBD calves at early time points. Platelet indices revealed a significant reduction in mean platelet volume (p = 0.047) and stable PDWc and plateletcrit values in the CBD group, suggesting modulation of inflammatory status. Alanine aminotransferase levels increased over time with a significant group effect (p = 0.014), indicating a mild hepatic response, while glucose and alkaline phosphatase remained within physiological ranges. These findings suggest that short-term CBD supplementation may transiently modulate stress and inflammatory responses during weaning, with potential benefits for physiological resilience. However, rebound endocrine effects and hepatic sensitivity highlight the need for further research to refine dosing strategies and assess long-term safety in dairy production systems. Full article

Background/Objectives: Calf diarrhea is a serious health problem in dairy farming, which seriously affects their production performance in adulthood. Diarrhea in calves is usually treated with antibiotics, which may lead to issues of antibiotic residue and resistance. Therefore, finding antibiotic alternatives is of critical importance. Yigong San (YGS) is a traditional Chinese medicine formula traditionally indicated for inflammatory gastrointestinal disorders. This study aimed to investigate whether YGS can be used as an alternative to antibiotics for the effective treatment of calf diarrhea and the underlying mechanisms. Methods: Ten healthy Holstein calves served as the control (Ctrl) group, while twenty diarrheic calves were randomly assigned to either a natural diarrhea (ND) group or a YGS treatment (YGS) group, which received YGS for seven days. Serum samples were collected post-treatment and analyzed for biochemical parameters, oxidative stress indicators, cytokine levels, and metabolomic profiles. Results: The results showed that YGS effectively alleviated diarrhea and improved abnormal biochemical indicators. YGS significantly increased serum levels of CAT, GSH-PX, and SOD, while reducing MDA levels. In addition, YGS also suppressed the expression of multiple proinflammatory cytokines, including IL-1α, TNF-α, IL-1β, IL-17A, IL-18, IL-21, IFN-γ, as well as chemokines CXCL9 and CXCL10. Metabolomic analysis revealed that YGS treatment significantly improved metabolic disorders and enriched the Arginine and Proline Metabolism pathways. The metabolites 1-methylhydantoin and ornithine were significantly and negatively correlated with pro-inflammatory cytokine levels. Conclusions: YGS effectively treats calf diarrhea by enhancing antioxidant capacity, reducing inflammatory factor levels, regulating immune function, and modulating serum metabolites. It provided valuable insights for the development of safe and effective antibiotic alternatives for preventing and treating calf diarrhea. Full article

This study evaluated the effects of supplementing dairy calves with Saccharomyces cerevisiae fermentation-derived postbiotics (SCFP) on growth, metabolism, immune status, and first lactation performance. Eighteen Holstein heifer calves were blocked by birth body weight and serum total protein and randomly assigned to control (CTR; n = 9; no supplementation) or SCFP (n = 9; 1 g/d SmartCare^® in milk replacer until weaning plus 5 g/d NutriTek^® until 70 d; Diamond V™, USA). Calves were weaned at 60 d and monitored until 160 d. Feed intake did not differ between groups. SCFP calves had greater post-weaning average daily gain from 71 to 100 d (0.93 vs. 0.60 kg/d, SCFP and CTR, respectively) and body weight from 100 to 160 d. They tended to have greater plasma β-hydroxybutyrate at 60 (0.32 vs. 0.27 mmol/L, SCFP and CTR, respectively) and 70 d (0.46 vs. 0.42, SCFP and CTR, respectively) and urea at 70 d (4.89 vs. 4.33 mmol/L, SCFP and CTR, respectively) and had greater acetate (515 vs. 384 μmol/L, SCFP and CTR, respectively) and propionate (33.13 vs. 22.4 ± 4.86 μmol/L, SCFP and CTR, respectively) at 60 d. SCFP calves also had lower nonesterified fatty acids at 21 d (0.23 vs. 0.38 mmol/L, SCFP and CTR, respectively), suggesting reduced energy mobilization during the most critical pre-weaning stage. Plasma myeloperoxidase was greater at 70 d (340 vs. 262 U/L, SCFP and CTR, respectively), as was phagocytosis by polymorphonuclear neutrophils at 60 (+10.4%) and 70 d (+8.2%). Feeding SCFP increased rumen activity and plasma volatile fatty acid concentrations, likely due to enhanced nutrient absorption and reduced weaning stress. SCFP calves exhibited a better immune response to lipopolysaccharide stimulation, as indicated by leukocyte gene expression, MPO, and PMN phagocytosis. Metagenomic analyses showed minor but significant changes in early-life microbiota composition at 7, 21, and 42 d. During first lactation, SCFP cows produced 2.1 kg/d more milk in the first 100 days in milk compared with CTR. In conclusion, early supplementation with SCFP supported rumen development, improved metabolic and immune function, and may enhance future productivity in dairy cows. Full article

Pasteurized colostrum has significantly contributed to improving the health and growth of newborn calves by reducing total bacterial count. However, previous research on animal responses to pasteurized colostrum has primarily focused on physiological functioning and production performance, especially during the preweaning period, with limited attention to any postweaning effects from the feeding of pasteurized colostrum at birth. We conducted a comprehensive investigation into the growth, health, blood immunity, and microbiota responses of dairy calves in these two groups from birth to 180 d of age. In this study, a total of 32 healthy female Holstein calves [mean birth weight = 39.8 ± 1.22 kg (mean ± standard deviation)] were selected and divided into two groups (n = 16; fed either pasteurized or unpasteurized colostrum at birth). The results demonstrated that calves fed pasteurized colostrum exhibited enhanced growth performance as indicated by higher body weight (BW) and average daily gain (ADG) compared to those fed unpasteurized colostrum (p < 0.05). Calves fed pasteurized colostrum displayed higher lymphocyte ratio (W-SCR) and platelet distribution width (PDW), along with lower neutrophil ratio (W-LCR) and neutrophil count (W-LCC) (p < 0.05). Additionally, substantial differences were identified in microbial richness and diversity between the pasteurized and unpasteurized colostrum-fed groups (p < 0.05). Distinct microbial communities were observed in the ruminal and fecal regions (p < 0.05), and we detected shared beneficial microbiota (Alloprevotella, Parabacteroides, and unidentified_Prevotellaceae) and metabolic functions (metabolism of energy, amino acids, and glycan) in both gut regions of the pasteurized group. Furthermore, our study revealed intricate and robust interactions among microbiota, volatile fatty acid (VFA) and blood indicators (|r| > 0.5 and p < 0.05). In conclusion, the findings in the present experiment suggest that the positive effects from d 0 pasteurized colostrum feeding may be seen up to d 180, including improved growth performance, health, and blood immunity, and these may be attributed to modifications in microbiota development induced by pasteurized colostrum. Full article

Neonatal calf diarrhea (NCD) remains one of the most prevalent and economically burdensome health challenges in preweaned calves, leading to compromised growth, increased morbidity, and high mortality rates worldwide. While traditional methods such as physical examination and clinical health scoring are widely used, they often require trained personnel, are resource-intensive, and are prone to subjectivity, which limits their scalability in large dairy operations. This observational cohort study investigated the feasibility of using suckle pressure measurement combined with machine learning (ML) techniques for NCD detection. A total of 51 female Holstein calves on a commercial dairy farm were enrolled at birth and health scored daily from 1 to 21 days of age. Suckle pressures were measured at 1, 3, 5, 7, 10, 14, and 21 days, as well as daily following NCD diagnosis until fecal consistency returned to normal. Pressure measurements were captured using impression film-wrapped nipples, producing 349 images, of which 54 were from calves diagnosed with NCD. Image features, including pixel density, color saturation, entropy, and histogram-based features, were extracted for analysis. Multiple ML classifiers—Support Vector Machine, K-Nearest Neighbors, Random Forest, Gradient Boosting, and Easy Ensemble (EE)—were applied to detect NCD status based on image features. The EE classifier achieved the best detection performance, with an accuracy of 0.90, precision of 0.64, and recall of 0.82, effectively handling data imbalance. Notably, the results also demonstrated that NCD onset could be predicted up to one day prior to clinical manifestation by training classifiers on pre-symptomatic suckle pressure data and testing on post-onset data. The EE classifier also outperformed other models in this early prediction window, with an accuracy of 0.74, precision of 0.67, and recall of 0.70. The results of our preliminary study suggest that suckle pressure may offer a novel, non-invasive approach for precision health monitoring in dairy systems, enabling timely intervention to reduce disease severity, improve calf health, and minimize economic losses. Full article

This study investigated the effects of dietary supplementation with varying doses of Clostridium butyricum (C. butyricum) on growth performance, diarrhea incidence, serum biochemical parameters, fecal short-chain fatty acids (SCFAs), and fecal microbiota in preweaning Holstein calves. Forty healthy newborn Holstein heifer calves with comparable birth weights were randomly assigned to four groups (control, 1 g/d supplementation, 3 g/d supplementation, and 5 g/d supplementation) for a 60-day trial. Growth parameters, diarrhea incidence, serum immunoglobulins (IgA, IgG, IgM), cytokines (IL-1β, TNF-α), antioxidant indicators (T-AOC, MDA), fecal short-chain fatty acids (SCFAs), and microbial composition were measured to evaluate the effects of C. butyricum. The results indicated that calves in the 5 g/d group exhibited a significantly higher average daily gain (ADG) compared with the control group (804.67 vs. 701.67 g/d, p < 0.05), with no significant differences in feed intake observed among groups (p > 0.05). During Days 22–42, the diarrhea incidence in the 5 g/d group was 7.74% lower than that in the control group (p < 0.05). This group exhibited significantly elevated serum IgM levels (Day 42, p < 0.05) and reduced IL-1β concentrations (Day 42, p < 0.05). Additionally, total antioxidant capacity (T-AOC) was significantly enhanced (Days 42 and 60, p < 0.05), while malondialdehyde (MDA) content was significantly decreased (Days 21 and 42, p < 0.05). At Day 42, fecal propionate and butyrate concentrations were significantly elevated in the 5 g/d group (p < 0.05), while the relative abundances of Bacteroides, Acidaminococcus, Bifidobacterium, Olsenella, Faecalitalea, and Ruminococcus were significantly increased (p < 0.05). The increase in these short-chain fatty acids and beneficial bacteria contributes to improved intestinal health and thus helps alleviate diarrhea. These findings indicate that supplementing preweaning calves’ milk with 5 g/d of C. butyricum significantly enhances growth performance and intestinal health. This provides evidence for the use of C. butyricum as a natural alternative to antibiotics in calf rearing. Full article

The transition period in dairy cows, spanning late pregnancy and early lactation, is associated with substantial metabolic and immunological challenges, leading to increased oxidative stress and inflammation. Selenium (Se), particularly in organic forms, supports antioxidant defenses, immune function, and metabolic regulation. This study investigated the effects of supplementing periparturient Holstein–Friesian cows with orally administered selenitetriglycerides (0.5 mg Se/kg body weight/day starting 12 days before the expected calving date and continuing until parturition) on antioxidant enzyme activity and on the hepatic expression of key inflammatory and metabolic genes. Serum selenium concentrations and erythrocyte glutathione peroxidase (GSH-Px) activity were assessed before and after parturition, and hepatic gene expression levels of tumor necrosis factor alpha (TNF-α), peroxisome proliferator-activated receptor alpha (PPAR-α) and delta (PPAR-δ) were assessed 24 h and 7 days postpartum. Supplemented cows showed significantly elevated serum Se levels and increased GSH-Px activity, reflecting improved antioxidant capacity. Moreover, hepatic expression of TNF-α and PPAR-δ was significantly reduced postpartum in the supplemented group, whereas PPAR-α expression remained stable. These findings indicate that selenitetriglycerides effectively enhance antioxidant defenses, moderate inflammation, and stabilize metabolic pathways during the periparturient phase, potentially reducing postpartum metabolic disorders and improving dairy-cow health. Full article

Colostrum is the milk harvested during the first few hours after calving, which contains high levels of immunoglobulins, antimicrobial peptides, and growth factors essential for the health of neonates. The primary objective of this study was to investigate the genetic background of colostrum quality traits (based on Brix percentage) in Holstein cows. Using phenotypic records of 58,338 Holstein cows from 37 dairy farms, we identified significant systematic effects influencing colostrum quality measured by digital Brix refractometer, estimated genetic parameters, and performed weighted single-step genome-wide association studies (WssGWAS) to identify genomic regions and candidate genes associated with these traits. The average (±SD) Brix percentage was 23.76 ± 3.25%. With heritability values ranging from 0.21 ± 0.03 (Brix in third parity) to 0.30 ± 0.02 (Brix in second parity), colostrum quality was determined to be moderately heritable. Genetic correlations between colostrum quality across parities ranged from 0.37 ± 0.14 to 0.81 ± 0.13. For colostrum quality from cows in the first, second, and third parities, WssGWAS enabled the identification of 30, 32, and 38 genomic regions explaining 4.18%, 4.42%, and 5.58% of the total additive genetic variance, respectively. Two immune-related genes (CNR1 and ZXDC) were identified as promising candidate genes for colostrum quality traits. In summary, colostrum quality measured in first parity cows should be evaluated as a different trait from measurements in later parities in breeding programs. These findings provide useful information for dairy breeders to genetically improve colostrum quality in dairy cattle populations. Full article

Trypanosoma vivax, a haemoprotozoan of African origin, has spread throughout Latin America, mainly affecting cattle through mechanical transmission by flies. This study reports an outbreak of T. vivax on a dairy farm in the midwestern region of São Paulo State, Brazil. Clinical signs included progressive weight loss, lethargy, hyporexia, reduced milk production, abortions, neurological signs, and deaths. The herd comprised 238 crossbred Holstein-Gir cattle (200 cows, 38 calves). Blood samples were collected from 104 randomly selected cows and all 38 calves to assess hematocrit (HCT) and total plasma protein (TPP), and detect trypomastigote forms using blood and buffy coat smears. PCR was performed on EDTA blood from 30 smear-negative cows. Trypanosoma sp. was identified in 51.9% (54/104) of the smear samples, with morphometric confirmation of T. vivax infection. About 66.6% (20/30) of the smear-negative cows tested positive by PCR, showing the higher sensitivity of molecular tests. Anemia was observed in 56.8% of infected cows, with significantly lower HCT and TPP values than in uninfected animals. The absence of quarantine for new animals, high fly density, and shared needles for oxytocin injections were likely contributing factors. This study underscores the crucial role of molecular diagnostics in accurately investigating outbreaks. Full article

The gross benefit of feeding multi-species probiotics has been reported, but the effect on the gut microbiota in pre-weaned dairy calves has not been elucidated. To address this gap, a randomized controlled trial was conducted in California, USA, to investigate the effect of feeding probiotics on the fecal microbiota of pre-weaned dairy calves. A total of 30 neonatal calves were randomly assigned to either the probiotic (PRO) or control (CON) treatment. Fecal samples were collected at four age timepoints: days 7, 14, 21, and 42. Fecal bacterial population was analyzed using 16S rRNA amplicon sequencing. Differential abundance analysis was conducted to investigate the difference between the PRO and CON treatments, and diarrheic and non-diarrheic calves in each PRO and CON group. The PRO group had decreased Clostridium perfringens and Fusobacterium varium compared to the CON at 7 days of age. At 7 days of age, diarrheic calves in CON had more abundant F. varium compared to non-diarrheic calves, but there was no difference between diarrheic and non-diarrheic calves in the PRO group. In conclusion, probiotics administration decreased the population of pathogenic bacteria in feces from pre-weaned dairy calves on Day 7 of age. However, the treatment did not have an impact on bacterial diversity. These results suggest that the administration of probiotics has the potential to control gastrointestinal pathogens. Full article