Oxidative Stress in Dairy Cows: Insights into the Mechanistic Mode of Actions and Mitigating Strategies

Investigating the Pharmacokinetics and Efficacy of Intramammary Ceftiofur Hydrochloride in Prevention of Udder Inflammation in Non-Lactating Dairy Heifers

Mastitis is the most burdensome concern for the dairy cattle industry. Antimicrobials are often prophylactically administered to dairy cows at dry-off to reduce the risk of intramammary infection during the dry period and subsequent lactation. Mastitis incidence has increased in dairy heifers after calving, leading to extralabel drug use of various dry cow products, including intramammary ceftiofur hydrochloride. However, the pharmacokinetics and efficacy of this application have yet to be studied. This study aimed to compare the pharmacokinetics and efficacy following no treatment, a non-antimicrobial teat sealant, or a single dose of intramammary ceftiofur given at 21 or 14 days before expected calving. We hypothesized that milk collected following dosing would contain drug residues below the FDA tolerance of 100 ng/mL by calving, and heifers within the ceftiofur treatment groups would have lower somatic cell counts (SCCs) than heifers in the teat sealant and nontreatment control groups. Following treatment or no treatment of 24 prepartum heifers, milk samples were collected until 21 days after calving. Somatic cell counts and ceftiofur concentrations were assessed utilizing a cell counter and UPLC/MS detection, respectively. Ceftiofur administration did not significantly reduce SCCs compared to other groups by days 7, 14, or 21. For heifers treated 14 and 21 days prior to calving, milk had a maximum ceftiofur concentration of 8.14 ± 6.24 and 4.20 ± 5.07 ng/mL 48 h into lactation, respectively. The minimal ceftiofur concentrations in milk collected from these heifers indicate that administration of ceftiofur 14 or 21 days before calving is unlikely to lead to violative residues. However, it is essential that regional regulations regarding the use of ceftiofur are adhered to.

Effect of body condition score loss during the transition period on metabolism, milk yield and health in Holstein cows

Introduction

This study aimed to investigate the impact of perinatal body condition score (BCS) and its subsequent loss on postpartum performance and health outcomes in dairy cattle.

Material and Methods

A total of 156 cows were randomly selected, and blood samples were collected at -21, 0, 7, 14, 21, 28 and 50 days relative to calving. Milk yield and disease incidence in dairy cows were recorded after calving. These cows were subsequently categorised into three groups based on BCS loss during the transition period: a no-BCS-loss (maintained BCS) group (M, 0 < BCS loss ≤ 0.25), low-BCS-loss group (L, 0.25 < BCS loss ≤ 0.5), and high-BCS-loss group (H, BCS loss > 0.5).

Results

All groups experienced a decline in BCS from 21 days prepartum through 50 days postpartum (P-value < 0.01). Cows in the H group had the highest levels of non-esterified fatty acids, beta-hydroxybutyrate, total cholesterol, aspartate aminotransferase, albumin, malondialdehyde and leptin (P-value < 0.05). Concomitantly, total antioxidant capacity, as well as the levels of insulin and glucose, were the lowest in group H (P-value < 0.05). Plasma concentrations of Ca, P, Mg and K, urea nitrogen and total bilirubin were not significantly influenced by BCS loss (P-value > 0.05). Cows in the M group were less likely to develop ketosis, mastitis, retained placenta, displaced abomasum and metritis than those in the H group, and cows in the H group produced the lowest milk yields (P-value < 0.05).

Conclusion

These observations collectively indicate that BCS loss is associated with measurable changes in energy balance, liver function, oxidative stress, daily milk production and disease incidence during the transition period.

Targeting Nrf2/KEAP1 signaling pathway using bioactive compounds to combat mastitis

Mastitis is a common inflammation of mammary glands that has a significantly impact on dairy production and animal health, causing considerable economic burdens worldwide. Elevated reactive oxygen species (ROS) followed by oxidative stress, apoptosis, inflammatory changes and suppressed immunity are considered the key biomarkers observed during mastitis. The Nrf2/KEAP1 signaling pathway plays a critical role in regulating antioxidant responses and cellular defense mechanisms. When activated by bioactive compound treatment, Nrf2 translocates to the nucleus and induces the expression of its target genes to exert antioxidant responses. This reduces pathogen-induced oxidative stress and inflammation by inhibiting NF-kB signaling in the mammary glands, one of the prominent pro-inflammatory signaling pathway. Here, we summarize recent studies to highlight the therapeutic potential of Nrf2/KEAP1 pathway in the prevention and treatment of mastitis. Collectively this review article aims to explore the potential of bioactive compounds in mitigating mastitis by targeting the Nrf2/KEAP1 signaling pathway.

Investigation of the Effect of Asprosin Level on Fertility Success and Oxidative Stress in Simmental Cows

Asprosin, a protein hormone that regulates hunger and glucose homeostasis, is produced by white adipose tissue. The aim of this study was to investigate the effect of asprosin level on fertility and oxidative stress parameters in Simmental cows. In the study, 44 Simmental multiparous cows were used. PRID was used to synchronise the animals. Blood samples were obtained from the cattle on the day of artificial insemination, and the amount of asprosin was measured. Animals were divided into two groups: a low asprosin (LA) group and a high asprosin (HA) group. On day 25, blood samples were taken, and pregnancy-associated glycoprotein (PAG2), total antioxidant level (TAS) and total oxidant level (TOS) were measured using commercial kits. Ultrasonography was used to diagnose pregnancy on day 45. The TAS level at day 25 was higher in the HA group than the TAS level at the beginning of the study (p = 0.007). The TOS level at the beginning of the study was higher in the HA group than in the LA group (p = 0.017). The TOS level of cows in the LA group on day 25 was significantly higher than the TOS level at the beginning of the study (p = 0.028). In conclusion, asprosin levels in cows affected oxidative stress parameters. According to receiver operating characteristic curve (ROC) analysis, there was a strong correlation between TOS and asprosin, and it was concluded that cows with HA values may be exposed to oxidative stress.

Oxidative Stress Biomarkers and Metabolic Parameters in Healthy Holstein Dairy Cows and Cows With Left Displacement Abomasum During the Transitional Period

BACKGROUND

During the transitional period, dairy cows experience oxidative stress and are more susceptible to diseases, including left displacement of the abomasum (LDA).

OBJECTIVES

This study aimed to compare oxidative stress biomarker levels in cows with LDA to those in healthy conditions and investigate the associations between predictive metabolites linked to LDA and oxidative stress biomarkers.

METHODS

In this case-control study, 400 healthy multiparous Holstein cows were matched for lactation number, milk production and calving date. Blood samples were collected at four time points: 21 and 7 days before, as well as 7 and 21 days after parturition from all animals. During the observation period, seven cows diagnosed with LDA in the main population, and seven healthy cows were randomly selected as controls for the comparison of oxidative stress, liver enzymes and metabolic parameters. Analysis of blood parameters utilized repeated measures ANOVA, and the degree of relationship between oxidative stress biomarkers and other measured parameters was assessed using Pearson correlations.

RESULTS

The LDA group exhibited significantly higher levels of urea, blood urea nitrogen (BUN), gamma-glutamyl transferase, glucose, cholesterol, triglyceride (TAG), β-hydroxybutyric acid (BHBA), aspartate aminotransferase (AST), sorbitol dehydrogenase, serum amyloid A (SAA), chloride, sodium, potassium, total antioxidant capacity (TAC) and malondialdehyde (MDA) compared to the control cows (p < 0.05). Positive correlations were observed among BUN, glucose, TB, AST, SAA, BHBA, TAG and MDA. Conversely, these parameters displayed negative correlations with TAC. Negative correlations were found among chloride, sodium, potassium, calcium, phosphorus and MDA, whereas positive correlations were observed with TAC.

CONCLUSIONS

These findings highlight the elevated level of oxidative stress and compromised antioxidant defence in cows with LDA and the intricate interplay among oxidative stress, metabolic parameters and liver enzymes.

Dietary Capsaicin Supplementation Mitigates Calving-Induced Stress and Enhances Antioxidant Capacity, Immune Function, and Gut Microbiota in Periparturient Dairy Cows

This study investigated the effects of dietary capsaicin supplementation on antioxidant capacity, immune function, and gut microbiota in periparturient dairy cows. Twenty Holstein cows with an average parity of 2.5 ± 0.76, milk production of 31.30 ± 2.39 kg, and 36.10 ± 2.38 days to calving were randomly assigned to either a control group fed a basal diet or a treatment group supplemented with 1.2 g/head/day of capsaicin. The supplementation was administered during an evaluation period spanning from 28 days before delivery to 21 days after delivery using a randomized block experimental design. Results showed that capsaicin significantly reduced milk somatic cell count and pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) while enhancing serum antioxidant enzymes (SOD, GSH-Px, and CAT) and immunoglobulin levels (IgG, IgA, and IgM). Moreover, capsaicin altered gut microbiota composition, increasing the relative abundance of beneficial genera. These findings suggest that dietary capsaicin supplementation during the transition period improves lactation performance and supports immune function, as well as alleviates oxidative stress. This study highlights the potential of capsaicin as a practical dietary strategy for enhancing productivity in dairy farming.

Milk metabolite profiling of dairy cows as influenced by mastitis

Mastitis is a disease with frequent incidence in dairy cows, causing huge financial losses to the dairy industry globally. The identification of certain biomarkers is crucial for the early diagnosis and management of mastitis. Metabolomics technology is a useful tool to accurately and efficiently analyze the changes of metabolites in biofluids in response to internal and external stimulations. Milk is the secreted by udder, and milk metabolites can directly reflect whether the udder are in the healthy or diseased state. The milk metabolomics analysis of mastitis can reveal the physiological and pathological changes of mammary gland and screen the related biomarkers, so as to offer useful reference for the prediction, diagnosis, and management of mastitis. Therefore, the aim of the present study was to comprehensively summarize milk metabolic change caused by naturally occurring or experimentally induced mastitis in dairy cows. In addition, comparative analysis and enrichment analysis were conducted to further discover potential biomarkers of mastitis and to identify the relevant pathways differentiating the healthy and mastitic cows. Multiple milk metabolites were identified to be altered during mastitis based on different metabolomics platforms. It was noteworthy that there were 28 metabolites not only identified by at least two different studies, but also showed consistent change tendency among the different studies. By comparison with literature, we further identified 12 milk metabolites, including acetate, arginine, β-hydroxybutyrate, carnitine, citrate, isoleucine, lactate, leucine, phenylalanine, proline, riboflavin, and valine that were linked with the occurrence of mastitis, which suggested that these 12 milk metabolites could be potential biomarkers of mastitis in dairy cows. Several pathways were revealed to explain the mechanisms of the variation of milk metabolites caused by mastitis, such as phenylalanine, tyrosine and tryptophan biosynthesis, arginine and proline metabolism, riboflavin metabolism, and tricarboxylic acid (TCA) cycle. These results offer a further understanding for the alteration of milk metabolites caused by mastitis, which have a potential significance in the development of more reliable biomarkers for mastitic diagnosis in dairy cows.

Genotype-Dependent Variations in Oxidative Stress Markers and Bioactive Proteins in Hereford Bulls: Associations with DGAT1, LEP, and SCD1 Genes

The objective of this study is to assess the influence of genetic polymorphisms in DGAT1, LEP, and SCD1 on the oxidative stress biomarkers and bioactive protein levels in Hereford bulls. A total of sixty-eight bulls were analyzed at 22 months of age to assess growth metrics and carcass quality, with a focus on polymorphisms in these genes. The key markers of oxidative stress, including malondialdehyde (MDA), and the activities of antioxidant enzymes such as glutathione reductase (GluRed), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were measured, alongside bioactive compounds like taurine, carnosine, and anserine. The results show that the TT genotype of DGAT1 is linked to significantly higher MDA levels, reflecting increased lipid peroxidation, but is also associated with higher GluRed and GPx activities and elevated levels of taurine, carnosine, and anserine, suggesting an adaptive response to oxidative stress. The LEP gene analysis revealed that the CC genotype had the highest MDA levels but also exhibited increased GPx and SOD activities, with the CT genotype showing the highest SOD activity and the TT genotype the highest total antioxidant status (TAS). The SCD1 AA genotype displayed the highest activities of GluRed, GPx, and SOD, indicating a more effective antioxidant defence, while the VA genotype had the highest MDA levels and the VV genotype showed lower MDA levels, suggesting protective effects against oxidative damage. These findings highlight genotype specific variations in the oxidative stress markers and bioactive compound levels, providing insights into the genetic regulation of oxidative stress and antioxidant defences, which could inform breeding strategies for improving oxidative stress resistance in livestock and managing related conditions.

Selenomethionine Mitigates Effects of Nocardia cyriacigeorgica-Induced Inflammation, Oxidative Stress, and Apoptosis in Bovine Mammary Epithelial Cells

Nocardia cyriacigeorgica causes bovine mastitis, reduces milk quantity and quality, and is often resistant to antimicrobials. Selenomethionine (SeMet) is a form of selenium, which reduces reactive oxygen species (ROS)-mediated apoptosis and intramammary infections. However, the protective effects of SeMet on N. cyriacigeorgica-infected bovine mammary epithelial cells (bMECs) are unclear. The objective of this study was to evaluate whether SeMet mitigated N. cyriacigeorgica-induced inflammatory injury, oxidative damage and apoptosis in bMECs. Cells were cultured with or without being pretreated with 40 µM of SeMet for 12 h, then challenged with N. cyriacigeorgica (multiplicity of infection = 5:1) for 6 h. Although N. cyriacigeorgica was resistant to lincomycin, erythromycin, enrofloxacin, penicillin, amoxicillin, cephalonium, cephalexin, and ceftriaxone, 40 μM SeMet increased cell viability and inhibited lactate dehydrogenase release in infected bMECs. Furthermore, N. cyriacigeorgica significantly induced mRNA production and protein expression of TNF-α, IL-1β, IL-6, and IL-8 at 6 h. Cell membrane rupture, cristae degeneration and mitochondria swelling were evident with transmission electron microscopy. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activities were down-regulated after 3, 6, or 12 h, whereas malondialdehyde (MDA) and ROS contents were significantly upregulated, with cell damage and apoptosis rapidly evident (the latter increased significantly in a time-dependent manner). In contrast, bMECs pretreated with 40 μM SeMet before infection, SOD, and GSH-px activities were upregulated (p < 0.05); MDA and ROS concentrations were downregulated (p < 0.05), and apoptosis was reduced (p < 0.05). In conclusion, 40 μM SeMet alleviated inflammation, oxidative stress and apoptosis induced by N. cyriacigeorgica in bMECs cultured in vitro.

Injection of antioxidant trace minerals/vitamins into peripartum crossbred cows improves the nutritional and immunological properties of colostrum/milk and the health of their calves under heat stress conditions

Multimineral and vitamin injections can provide better nutrient availability at the cellular level, which is essential for mitigating transition period stress and improving the wellbeing and productivity of dairy cows. The present study was conducted to assess the colostrum quality and calf health after intramuscular injection of multi-minerals (MM) and multi-vitamins (MV) to peripartum cows during winter (THI = 58 to 66) and summer (THI = 78 to 82) months. In each season, twenty-four pregnant crossbred Karan Fries cows were grouped into four, each consisting of six cows. Group I, referred to as the Control, received solely the basal diet, without any additional supplements. Groups II, III, and IV were administered additional MM (T1), MV (T2), and a combined MM and MV (T3) along with their basal diet, starting 30 days before calving and continuing for 30 days after calving. Blood samples were collected from the calves, while colostrum/milk samples were obtained from the cows on days 1, 3, 7, and 15 after calving. The somatic cell counts (SCC) in the milk were determined using a cell counter. Cortisol, IgG, IGF1 and total immunoglobulins (TIG) in whey and plasma from cow colostrum/milk or calf blood samples were estimated by ELISA. Cows that calved in the summer exhibited notably reduced levels (P < 0.05) of IgG, milk, and plasma IGF1, along with lower calf body weights, in comparison to those calving in the winter season. Furthermore, the summer months saw significant increases (P < 0.05) in plasma and milk cortisol levels, as well as total somatic cell counts (SCC) in both colostrum and milk samples. Maximum beneficial effect was observed in T3 group. Results indicate that injections to peripartum cows could be an important strategy for improving colostrum quality and calf health during the summer seasons.

Alpha-Synuclein Interaction with UBL3 Is Upregulated by Microsomal Glutathione S-Transferase 3, Leading to Increased Extracellular Transport of the Alpha-Synuclein under Oxidative Stress

Aberrant aggregation of misfolded alpha-synuclein (α-syn), a major pathological hallmark of related neurodegenerative diseases such as Parkinson's disease (PD), can translocate between cells. Ubiquitin-like 3 (UBL3) is a membrane-anchored ubiquitin-fold protein and post-translational modifier. UBL3 promotes protein sorting into small extracellular vesicles (sEVs) and thereby mediates intercellular communication. Our recent studies have shown that α-syn interacts with UBL3 and that this interaction is downregulated after silencing microsomal glutathione S-transferase 3 (MGST3). However, how MGST3 regulates the interaction of α-syn and UBL3 remains unclear. In the present study, we further explored this by overexpressing MGST3. In the split Gaussia luciferase complementation assay, we found that the interaction between α-syn and UBL3 was upregulated by MGST3. While Western blot and RT-qPCR analyses showed that silencing or overexpression of MGST3 did not significantly alter the expression of α-syn and UBL3, the immunocytochemical staining analysis indicated that MGST3 increased the co-localization of α-syn and UBL3. We suggested roles for the anti-oxidative stress function of MGST3 and found that the effect of MGST3 overexpression on the interaction between α-syn with UBL3 was significantly rescued under excess oxidative stress and promoted intracellular α-syn to extracellular transport. In conclusion, our results demonstrate that MGST3 upregulates the interaction between α-syn with UBL3 and promotes the interaction to translocate intracellular α-syn to the extracellular. Overall, our findings provide new insights and ideas for promoting the modulation of UBL3 as a therapeutic agent for the treatment of synucleinopathy-associated neurodegenerative diseases.

The mammosphere-derived epithelial cell secretome modulates neutrophil functions in the bovine model

Background

Innovative therapies against bacterial infections are needed. One approach is to focus on host-directed immunotherapy (HDT), with treatments that exploit natural processes of the host immune system. The goals of this type of therapy are to stimulate protective immunity while minimizing inflammation-induced tissue damage. We use non-traditional large animal models to explore the potential of the mammosphere-derived epithelial cell (MDEC) secretome, consisting of all bioactive factors released by the cells, to modulate host immune functions. MDEC cultures are enriched for mammary stem and progenitor cells and can be generated from virtually any mammal. We previously demonstrated that the bovine MDEC secretome, collected and delivered as conditioned medium (CM), inhibits the growth of bacteria in vitro and stimulates functions related to tissue repair in cultured endothelial and epithelial cells.

Methods

The immunomodulatory effects of the bovine MDEC secretome on bovine neutrophils, an innate immune cell type critical for resolving bacterial infections, were determined in vitro using functional assays. The effects of MDEC CM on neutrophil molecular pathways were explored by evaluating the production of specific cytokines by neutrophils and examining global gene expression patterns in MDEC CM-treated neutrophils. Enzyme linked immunosorbent assays were used to determine the concentrations of select proteins in MDEC CM and siRNAs were used to reduce the expression of specific MDEC-secreted proteins, allowing for the identification of bioactive factors modulating neutrophil functions.

Results

Neutrophils exposed to MDEC secretome exhibited increased chemotaxis and phagocytosis and decreased intracellular reactive oxygen species and extracellular trap formation, when compared to neutrophils exposed to control medium. C-X-C motif chemokine 6, superoxide dismutase, peroxiredoxin-2, and catalase, each present in the bovine MDEC secretome, were found to modulate neutrophil functions.

Conclusion

The MDEC secretome administered to treat bacterial infections may increase neutrophil recruitment to the site of infection, stimulate pathogen phagocytosis by neutrophils, and reduce neutrophil-produced ROS accumulation. As a result, pathogen clearance might be improved and local inflammation and tissue damage reduced.

Effects of parity and week after calving on the metabolic, redox and immune status of dairy cows

At the onset of lactation in dairy cows, inflammation and oxidative stress may occur and result in a risk of pathologies and lower milk yield. To propose an innovative management strategy for cows during this period, it is essential to better understand these physiological variations. Our objective was to evaluate the metabolic, redox and immune status of 7 primiparous and 8 multiparous Holstein cows during late gestation and the first months of lactation. Blood samples were collected between 3 weeks before calving until 12 weeks postpartum. Milk samples were also collected, but only at the time points after calving. The metabolic (nonesterified fatty acids (NEFA), BHB, glucose, urea, calcium) and redox (reactive oxygen metabolites (ROM), oxidative stress index (OSI), glutathione peroxidase activity, vitamin E) statuses were analyzed in plasma or erythrocytes. The expression of genes related to antioxidant functions was determined in leukocytes collected from milk. For immune status, plasma cytokine levels and the production of reactive oxygen species (ROS) in classical and regulatory neutrophils were measured in 2 whole blood ex vivo challenges. The data were analyzed using a mixed model that included the fixed effects of parity and week and their interaction. Milk yield, plasma NEFA and BHB in wk 2 and 4 after calving were higher in multiparous cows than in primiparous cows, whereas glucose and calcium tended to be lower. Plasma ROM and OSI levels in wk 8 were higher in multiparous than in primiparous cows. Multiparous cows also displayed higher glutathione peroxidase activity in erythrocytes, and antioxidant transcription factor and superoxide dismutase-1 expression levels in milk leukocytes. Moreover, multiparous cows had higher plasma concentrations of vitamin E but lower plasma levels of cytokines CXCL10, CCL2, IL1Rα and IFNγ. Following ex vivo whole blood stimulation with Escherichia coli, lower IL1α and TNFα levels were measured in multiparous than in primiparous cows. Intracellular ROS production by neutrophils was lower in multiparous than in primiparous cows. These results thus indicated marked physiological changes in wk 8 compared with wk 2 and 4 of lactation. These differences in the physiological status of primiparous and multiparous cows offer interesting perspectives for potential dietary strategies to prevent pathologies which take account of parity and week relative to calving.

Supplementation with Combined Additive Improved the Production of Dairy Cows and Their Offspring with Maintenance of Antioxidative Stability

Oxidative stress damage in periparturient cows decreases both production and their health; supplementation with complex additives during the periparturient period has been used as an important strategy to enhance the antioxidant status and production of dairy cows. The periparturient cows not only risk a negative energy balance due to reduced dry matter intake but also represent a sensitive period for oxidative stress. Therefore, we have developed an immunomodulatory and nutritional regulation combined additive (INC) that hopefully can improve the immune status and production of cows during the periparturient period and their offspring health and growth by improving their antioxidant stress status. The INC comprised a diverse array of additives, including water-soluble and fat-soluble vitamins, Selenomethionine, and active dry Saccharomyces cerevisiae. Forty-five multiparous Holstein cows were randomly assigned to three treatments: CON (no INC supplementation, n = 15), INC30 (30 g/d INC supplementation, n = 15), and INC60 (60 g/d INC supplementation, n = 15) based on last lactation milk yield, body condition score, and parity. Newborn calves were administered 4 L of maternal colostrum originating from the corresponding treatment and categorized based on the treatment received by their respective dams. The INC not only served to maintain the antioxidative stress system of dairy cows during the periparturient period but also showed a tendency to improve the immune response (lower tumor necrosis factor and interleukin-6) during the perinatal period. A linear decrease in concentrations of alkaline phosphatase postpartum and β-hydroxybutyrate was observed with INC supplementation. Milk fat yield, milk protein yield, and energy-corrected milk yield were also increased linearly with increasing additive supplementation. Calves in the INC30 group exhibited greater wither height and chest girth but no significant effect on average daily gain or body weight. The diarrhea frequency was linearly decreased with the incremental level of INC. Results indicate that supplementation with INC in peripartum dairy cows could be a major strategy to improve immune response, decrease inflammation, maintain antioxidant stress status in transition dairy cows, and have merit in their calves. In conclusion, this study underlines the benefits of INC supplementation during the transition period, as it improved anti-inflammatory capacity, could positively impact antioxidative stress capacity, and eventually enhanced the production performance of dairy cows and the health and growth of calves.

Evaluation of phytochemicals from Thymus serpyllum as potential drug candidates to manage oxidative stress in transition dairy cows

Dairy cows undergo immense stress and experience autoimmune reactions during the transition period, majorly due to the generation of ROS in the body. So, pharmacological approaches are needed to manage oxidative stress in the transition cows. Recently, the use of phytochemicals as feed additives in cows' nutrition has gained interest in managing various disease conditions. In the current study, we have evaluated the potential effects of phytochemicals derived from methanolic extract of Thymus serpyllum against oxidative stress and autoimmunity via inhibition of bovine nuclear factor kappa B (NF-κB). The free radical scavenging activity of Thymus serpyllum seed and leaf extracts was 71.8 and 75.6%, respectively at 100 µg/mL concentration. Similarly, both extracts displayed radicals reducing power and inhibition of lipid-peroxidation maximally at 100 µg/mL. A total of 52 bioactive compounds were identified when the plant extract was characterized by the GC-MS analysis, and five (Thymol, Luteolin 7-o-glucuronide, Rosmarinic acid, Apigenin 6,8-di-c-glucoside, Kaempferol) had binding free energy values of -11.6433, -10.002, -8.2615, -7.1714, -6.4870, respectively, in complexes with bovine NF-κB. Through computational analysis, the screened compounds showed good pharmacokinetic parameters, including non-toxicity, non-carcinogenic, high gastrointestinal absorption and thus can serve as potential drug candidates. MD simulation studies predicted the stability of complexes and the complex of Kaempferol was most stable based on RSMD value and MM/GBSA binding energy. The biochemical assays and computational studies indicated that Thymus serpyllum could be used as a promising feed additive in dairy cows to manage oxidative stress during the transition period.Communicated by Ramaswamy H. Sarma.

Enhancing bovine immune, antioxidant and anti-inflammatory responses with vitamins, rumen-protected amino acids, and trace minerals to prevent periparturient mastitis

Mastitis, the inflammatory condition of mammary glands, has been closely associated with immune suppression and imbalances between antioxidants and free radicals in cattle. During the periparturient period, dairy cows experience negative energy balance (NEB) due to metabolic stress, leading to elevated oxidative stress and compromised immunity. The resulting abnormal regulation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), along with increased non-esterified fatty acids (NEFA) and β-hydroxybutyric acid (BHBA) are the key factors associated with suppressed immunity thereby increases susceptibility of dairy cattle to infections, including mastitis. Metabolic diseases such as ketosis and hypocalcemia indirectly contribute to mastitis vulnerability, exacerbated by compromised immune function and exposure to physical injuries. Oxidative stress, arising from disrupted balance between ROS generation and antioxidant availability during pregnancy and calving, further contributes to mastitis susceptibility. Metabolic stress, marked by excessive lipid mobilization, exacerbates immune depression and oxidative stress. These factors collectively compromise animal health, productive efficiency, and udder health during periparturient phases. Numerous studies have investigated nutrition-based strategies to counter these challenges. Specifically, amino acids, trace minerals, and vitamins have emerged as crucial contributors to udder health. This review comprehensively examines their roles in promoting udder health during the periparturient phase. Trace minerals like copper, selenium, and calcium, as well as vitamins; have demonstrated significant impacts on immune regulation and antioxidant defense. Vitamin B12 and vitamin E have shown promise in improving metabolic function and reducing oxidative stress followed by enhanced immunity. Additionally, amino acids play a pivotal role in maintaining cellular oxidative balance through their involvement in vital biosynthesis pathways. In conclusion, addressing periparturient mastitis requires a holistic understanding of the interplay between metabolic stress, immune regulation, and oxidative balance. The supplementation of essential amino acids, trace minerals, and vitamins emerges as a promising avenue to enhance udder health and overall productivity during this critical phase. This comprehensive review underscores the potential of nutritional interventions in mitigating periparturient bovine mastitis and lays the foundation for future research in this domain.

Is heat stress a growing problem for dairy cattle husbandry in the temperate regions? A case study of Baden-Württemberg in Germany

Heat stress with measurable effects in dairy cattle is a growing concern in temperate regions. Heat stress in temperate regions differs between environments with different geophysical characteristics. Microclimates specific to each environment were found to greatly impact at what level heat stress occurs and will occur in the future. The landlocked state of Baden-Württemberg, Germany, provides several different environments, hence, a good case-study. Temperature-Humidity Index (THI) from 17 weather stations for the years 2003 to 2022 was calculated and milking yields from 22 farms for the years 2017 to 2022 were collected. The occurrences and evolving patterns of heat stress were analyzed with the use of a THI, and the effect of heat stress on milk yield was analyzed based on milking records from Automated Milking Systems. Daily average THI was calculated using hourly readings of relative humidity and ambient temperature, disregarding solar radiation and wind, as all animals were permanently stabled. Based on studies conducted in Baden-Württemberg and neighboring regions, cited ahead in the section of THI, THI = 60 was the threshold for heat stress occurrence. Findings show that the heat stress period varied between stations from 64 to 120 d with THI ≥ 60 in a year. This aligns with yearly and summer averages, also steadily increasing from May to September. The length of the heat stress period was found to increase 1 extra day every year. Extreme weather events such as heat waves did not increase the heat stress period of that year in length but increased the average THI. Milk yield was found to be significantly (α = 0.05) different between counties grouped into different zones according to heat stress severity and rate of increase in daily average THI. Future attempts at managing heat stress on dairy cattle farms in the temperate regions should account for microclimate, as geographical proximity does not mean that the increase in heat stress severity will be the same in the 2 neighboring areas.

Selenium suppressed the LPS-induced oxidative stress of bovine endometrial stromal cells through Nrf2 pathway with high cortisol background

Stress and infection seriously threaten the reproductive performance and health of dairy cows. Various perinatal stresses increase plasma cortisol concentrations in cows, and chronically high cortisol levels may increase the incidence and severity of the uterine diseases. Selenium (Se) enhances antioxidant capacity of cows. The aim of this study was to explore how Se affects the oxidative stress of primary bovine endometrial stromal cells (BESC) with high cortisol background. The levels of reactive oxygen species (ROS) and other biomarkers of oxidative stress were measured using flow cytometry and assay kits. The changes in nuclear NF-E2-related factor 2 (Nrf2) pathway were detected by Western blot, qPCR, and immunofluorescence. The result showed that lipopolysaccharide (LPS) increased (P < 0.01) ROS and malondialdehyde (MDA) content and reduced (P < 0.01) superoxide dismutase (SOD) concentration, provoking BESC oxidative stress. The elevated levels of cortisol resulted in the accumulation (P < 0.05) of ROS and MDA and inhibition (P < 0.05) of SOD in unstimulated BESC but demonstrated an antioxidative effect in LPS-stimulated cells. Pretreatment with Se reduced (P < 0.01) the levels of ROS and MDA, while increasing (P < 0.05) the antioxidant capacities and the relative abundance of gene transcripts and proteins related to the Nrf2 pathway in BESC. This antioxidant effect was more pronounced in the presence of high cortisol level. In conclusion, cortisol alone induced the oxidative damage but provided an antioxidant protection in the presence of LPS. Se alleviated the LPS-induced cellular oxidative stress, which is probably achieved through activating Nrf2 pathway. At high cortisol levels, Se supplement has a more significant protective effect on BESC oxidative stress. This study provided evidence for the protective role of Se in bovine endometrial oxidative damage of stressed animals and suggested the potential regulatory mechanism in vitro.

A multispecies bacterial-based direct-fed microbial alleviates Salmonella invasion and supports in vitro epithelial integrity

Managing bacterial infections is of great importance in livestock production, particularly those caused by Salmonella enterica serovars Typhimurium or Dublin, which can impact both animal health and performance, as well as human food safety. Direct-fed microbials (DFM) can support gastrointestinal function and alleviate the potential negative effects of bacterial infections. In the present study, the capacity of a multispecies bacterial-based DFM containing Ligilactobacillus (formerly Lactobacillus) animalis 506, Propionibacterium freudenreichii 507, Bacillus licheniformis 809, and B. subtilis 597 to reduce S. Typhimurium ATCC14028 invasion was investigated using a co-incubation model with the HT29-MTX-E12 cell line (experiment 1). Next, a possible antagonistic effect of the DFM against S. Dublin ATCC 41286 was evaluated using an in vitro agar well diffusion method following a co-incubation of 48 h (experiment 2). At last, a series of experiments were performed to evaluate how different doses (6.25 × 106, 2.50 × 107, or 1.00 × 108 CFU/well) of the DFM would support the integrity of intestinal epithelial cells challenged or not with S. Typhimurium ATCC14028 or hydrogen peroxide under a transepithelial electrical resistance (TEER) assay with Caco-2 cells (experiments 3 and 4). In experiment 1, BDP significantly (P < 0.001) reduced by 90.8% the invasion of S. Typhimurium into HT29-MTX-E12 cells, whereas viability of the potentially harmful bacteria was reduced by 21.0% (P < 0.0001). In experiment 2, the antagonistic properties of BDP towards S. Dublin were confirmed by the detection of a clear inhibition zone (size = 8.6 mm). Lastly, without challenge, the lowest dose of the DFM (6.25 × 106 CFU) provided the greatest support to the cells (treatment × hour; P < 0.0001). However, when the cells were challenged with S. Typhimurium, all doses alleviated the loss of integrity caused by the pathogen (treatment × hour; P < 0.0001). In cells challenged with hydrogen peroxide, the greater dose (1.00 × 108 CFU) supported the cells for a longer period of time (treatment × hour; P < 0.0001). These in vitro findings set the stage for exploring the potential benefits of using a novel DFM as a promising tool and strategy to mitigate S. enterica infections in ruminants and improve animal health, food safety, and public health. Further, in vivo confirmation needs to be developed to validate these preliminary in vitro results.

Extracellular Vesicles Derived from Selenium-Deficient MAC-T Cells Aggravated Inflammation and Apoptosis by Triggering the Endoplasmic Reticulum (ER) Stress/PI3K-AKT-mTOR Pathway in Bovine Mammary Epithelial Cells

Selenium (Se) deficiency disrupts intracellular REDOX homeostasis and severely deteriorates immune and anti-inflammatory function in high-yielding periparturient dairy cattle. To investigate the damage of extracellular vesicles derived from Se-deficient MAC-T cells (SeD-EV) on normal mammary epithelial cells, an in vitro model of Se deficiency was established. Se-deficient MAC-T cells produced many ROS, promoting apoptosis and the release of inflammatory factors. Extracellular vesicles were successfully isolated by ultrahigh-speed centrifugation and identified by transmission electron microscopy, particle size analysis, and surface markers (CD63, CD81, HSP70, and TSG101). RNA sequencing was performed on exosomal RNA. A total of 9393 lncRNAs and 63,155 mRNAs transcripts were identified in the SeC and SeD groups, respectively, of which 126 lncRNAs and 955 mRNAs were differentially expressed. Furthermore, SeD-EV promoted apoptosis of normal MAC-T cells by TUNEL analysis. SeD-EV significantly inhibited Bcl-2, while Bax and Cleaved Caspase3 were greatly increased. Antioxidant capacity (CAT, T-AOC, SOD, and GSH-Px) was inhibited in SeD-EV-treated MAC-T cells. Additionally, p-PERK, p-eIF2α, ATF4, CHOP, and XBP1 were all elevated in MAC-T cells supplemented with SeD-EV. In addition, p-PI3K, p-Akt, and p-mTOR were decreased strikingly by SeD-EV. In conclusion, SeD-EV caused oxidative stress, thus triggering apoptosis and inflammation through endoplasmic reticulum stress and the PI3K-Akt-mTOR signaling pathway, which contributed to explaining the mechanism of Se deficiency causing mastitis.

Prognostic potential of inflammatory markers, oxidative status, thrombocyte indices, and renal biochemical markers in neonatal calf diarrhoea-induced systemic inflammatory response syndrome

The study aimed to assess the prognostic value of inflammatory markers, indicators of oxidative stress, thrombocyte indices, and renal biochemical markers in neonatal calf diarrhoea (NCD) induced by systemic inflammatory response syndrome (SIRS) upon admission. A prospective, observational, and case-control study was conducted on 56 calves diagnosed with NCD. Mean concentrations of interleukin-6 (IL-6), malondialdehyde (MDA), glutathione (GSH), mean platelet volume (MPV), platelet distribution width (PDW), blood urea nitrogen (BUN), and creatinine (Crea) were measured. Furthermore, the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were also calculated for SIRS survivors [SIRS (survivor)] and non-survivors [SIRS (non-survivor)] induced by NCD. A prognostic cut-off value for predicting the prognosis of the SIRS's induced by NCD was obtained via receiver operating characteristic (ROC) curve analysis. Upon admission, the SIRS (non-survivor) calves had significantly higher (P < .001) average levels of IL-6, MDA, BUN, Crea, MPV, and PDW compared to the SIRS (survivor) calves and significantly lower (P < .001) average levels of GSH. Despite an apparent increase in the NLR and PLR values of calves diagnosed with SIRS, no significant difference was found between the survival and non-survivor SIRS cases. Positive predictive values (PPVs) for survival were determined as 100 %, 100 %, 80 %, 100 %, 80 %, and 80 %, respectively, using cut-off values of IL-6 (≤259.67 ng/L), MDA (≤2.87 nmol/mL), MPV (≤12.5 fL), PDW (≤34.25 %), BUN (≤168.3 mg/dL), and Crea (≤2.11 mg/dL). The determined threshold values are those obtained upon admission to the hospital. Based on the sensitivity, specificity, and PPVs derived from the ROC analysis, it has been concluded that IL-6, MDA, MPV, PDW, BUN, and Crea are the most relevant biomarkers used for predicting the prognosis of NCD-induced SIRS in calves. Furthermore, it is also noteworthy that IL-6 exhibited the highest effectiveness among all biomarkers.

MicroRNA miR-223 modulates NLRP3 and Keap1, mitigating lipopolysaccharide-induced inflammation and oxidative stress in bovine mammary epithelial cells and murine mammary glands

Bovine mastitis, the most prevalent and costly disease in dairy cows worldwide, decreases milk quality and quantity, and increases cow culling. However, involvement of microRNAs (miRNAs) in mastitis is not well characterized. The objective was to determine the role of microRNA-223 (miR-223) in regulation of the nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome and kelch like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) oxidative stress pathway in mastitis models induced by lipopolysaccharide (LPS) treatment of immortalized bovine mammary epithelial cells (bMECs) and murine mammary glands. In bMECs cultured in vitro, LPS-induced inflammation downregulated bta-miR-223; the latter interacted directly with the 3' untranslated region (3' UTR) of NLRP3 and Keap1. Overexpression of bta-miR-223 in bMECs decreased LPS and Adenosine 5'-triphosphate (ATP)-induced NLRP3 and its mediation of caspase 1 and IL-1β, and inhibited LPS-induced Keap1 and Nrf2 mediated oxidative stress, whereas inhibition of bta-miR-223 had opposite effects. In an in vivo murine model of LPS-induced mastitis, increased miR-223 mitigated pathology in the murine mammary gland, whereas decreased miR-223 increased inflammatory changes and oxidative stress. In conclusion, bta-miR-223 mitigated inflammation and oxidative injury by downregulating the NLRP3 inflammasome and Keap1/Nrf2 signaling pathway. This study implicated bta-miR-223 in regulation of inflammatory responses, with potential as a novel target for treating bovine mastitis and other diseases.

UBL3 Interaction with α-Synuclein Is Downregulated by Silencing MGST3

Ubiquitin-like 3 (UBL3) is a membrane-anchored protein that plays a crucial role in sorting proteins into small extracellular vesicles. Aggregations of alpha-synuclein (α-syn) are associated with the pathology of neurodegenerative diseases such as Parkinson's disease. Recently, the interaction between UBL3 and α-syn was discovered, with potential implications in clearing excess α-syn from neurons and its role in disease spread. However, the regulator that can mediate the interaction between UBL3 and α-syn remains unclear. In this study, using the split gaussian luciferase complementation assay and RNA interference technology, we identified that QSOX2, HTATIP2, UBE3C, MGST3, NSF, HECTD1, SAE1, and ATG3 were involved in downregulating the interaction between UBL3 and α-syn. Notably, silencing MGST3 had the most significant impact. Immunocytochemistry staining confirmed the impact of MGST3 silencing on the co-localization of UBL3 and α-syn in cells. MGST3 is a part of the antioxidant system, and silencing MGST3 is believed to contribute to oxidative stress. We induced oxidative stress with hydrogen peroxide, observing its effect on the UBL3-α-syn interaction, and showing that 800 µM of H2O2 downregulated this interaction. In conclusion, silencing MGST3 downregulates the interaction between UBL3 and α-syn.

Heat stress affects dairy cow health status through blood oxygen availability

BACKGROUND

Rises in global warming and extreme weather occurrence make the risk of heat stress (HS) induced by high ambient temperatures more likely in high-yielding dairy cows, resulting in low milk quality and yield. In animals, oxygen is involved in many physiological and metabolic processes, but the effects of HS on oxygen metabolism remain unclear. Thus, the current study aimed to investigate how oxygen metabolism plays a role in health status of dairy cows by measuring the milk yield, milk composition, and blood biochemical variables of cows under different levels of HS: none (No-HS), mild (Mild-HS), and moderate HS (Mod-HS).

RESULTS

The HS significantly increased rectal temperature (Ptreat < 0.01) and respiration rate (Ptreat < 0.01). Under Mod-HS, greater Na+ (P < 0.05) and lower total CO2, and pH (P < 0.05) were observed relative to those under No-HS and Mild-HS. Oxygen concentrations in both coccygeal artery and mammary vein (Ptreat < 0.01) were lower under Mod-HS than under No-HS. Coccygeal vein concentrations of heat shock protein 90 (HSP90) (P < 0.05) increased during Mod-HS compared with those in cows under No-HS. Malondialdehyde increased during Mod-HS, and glutathione peroxidase (P < 0.01) increased during Mild-HS. Coccygeal vein concentrations of vascular endothelial growth factor (P < 0.01), heme oxygenase-1 (P < 0.01), and hypoxia-inducible factor 1α (P < 0.01) were greater in cows under Mod-HS than those under No-HS. Red blood cell count (P < 0.01) and hemoglobin concentration (P < 0.01) were lower in the coccygeal vein of dairy cows under Mild- and Mod-HS than those of cows under No-HS.

CONCLUSIONS

Exposure to HS negatively impacts the health status and lactation performance of dairy cows by limiting oxygen metabolism and transportation. However, the specific mechanism by which HS affects mammary function in cows remains unclear and requires further exploration.

Use of green microalgae Chlorella as a nutritional supplement to support oocyte and embryo production in goats

This study aimed to evaluate the use of green microalgae as a nutritional supplement for oocyte and embryo production in goats. Two experiments were performed on adult goats to obtain oocytes (EVO; n = 14) and in vivo embryos (IVD; n = 14). In both, the donors were divided into control (n = 7) and Chlorella (n = 7) groups. All goats received a base diet, and donors were orally supplemented with Chlorella pyrenoidosa (CH) in the Chlorella groups. For EVO, donors received 10 g CH for 14 days, and for IVD, 20 g CH was given for six days before embryo recovery. In EVO and IVD, food intake in the CH group was comparatively low, and it showed relatively high subcutaneous adipose deposition. In addition, the CH group exhibited an increase in triglyceride, cholesterol, and plasma glucose levels. In IVD, a significant increase in peripheral glutathione peroxidase levels was noticed. In EVO, the CH group showed relatively large follicular size and an increase in intrafollicular levels of triglycerides, glucose, and glutathione peroxidase. No differences were observed in the oocyte collected, and CH oocytes showed a low intensity of MitoTracker fluorescence (MT). In IVD, the CH group had a high proportion of transferable embryos, and these structures exhibited high fluorescence intensities for MT and H2DCFDA probes. We concluded that under these conditions, CH did not enhance the quality of the recovered oocytes. However, a daily dose of 20 g CH improved the quality of embryos and stimulated their mitochondrial functionality.

Blood biochemical changes upon subclinical intramammary infection and inflammation in Holstein cattle

The aim of this study was to investigate the associations between subclinical intramammary infection (IMI) from different pathogens combined with inflammation status and a set of blood biochemical traits including energy-related metabolites, indicators of liver function or hepatic damage, oxidative stress, inflammation, innate immunity, and mineral status in 349 lactating Holstein cows. Data were analyzed with a linear model including the following fixed class effects: days in milk, parity, herd, somatic cell count (SCC), bacteriological status (positive and negative), and the SCC × bacteriological status interaction. Several metabolites had significant associations with subclinical IMI or SCC. Increased SCC was associated with a linear decrease in cholesterol concentrations which ranged from -2% for the class ≥50,000 and <200,000 cells/mL to -11% for the SCC class ≥400,000 cells/mL compared with the SCC class <50,000 cells/mL. A positive bacteriological result was associated with an increase in bilirubin (+24%), paraoxonase (+11%), the ratio paraoxonase/cholesterol (+9%), and advanced oxidation protein product concentration (+23%). Increased SCC were associated with a linear decrease in ferric reducing antioxidant power concentrations ranging from -3% for the class ≥50,000 and <200,000 cells/mL to -9% for the SCC class ≥400,000 cells/mL (respect to the SCC class <50,000 cells/mL). A positive bacteriological result was associated with an increase in haptoglobin concentrations (+19%). Increased SCC were also associated with a linear increase in haptoglobin concentrations, which ranged from +24% for the class ≥50,000 and <200,000 cells/mL (0.31 g/L) to +82% for the SCC class ≥400,000 cells/mL (0.45 g/L), with respect to the SCC class <50,000 cells/mL (0.25 g/L). Increased SCC were associated with a linear increase in ceruloplasmin concentrations (+15% for SCC ≥50,000 cells/mL). The observed changes in blood biochemical markers, mainly acute phase proteins and oxidative stress markers, suggest that cows with subclinical IMI may experience a systemic involvement.

The effect of propolis extract on milk production and composition, serum biochemistry, and physiological parameters of heat-stressed dairy cows

The aim of this study was to evaluate whether feeding propolis extract (PE) influences nutrient intake, milk production and composition, serum biochemistry, and physiological parameters of heat-stressed dairy cows. For this purpose, we used three primiparous Holstein cows with a lactation period of 94 ± 4 days and with 485 ± 13 kg body weight. The treatments were 0 mL/day, 32 mL/day, and 64 mL/day of PE randomly assigned in a 3x3 Latin square design, repeated over time. The experiment lasted a total of 102 days; each Latin square lasted 51 days divided into three 17-day periods (12 days for adaptation and five days for data collection). The PE supply did not influence (P > 0.05) the cows' intake of dry matter (18.96 kg/d), crude protein (2.83 kg/d), and neutral detergent-insoluble fiber (7.36 kg/d), but there was an increase in feeding time with the 64 ml/day PE supply (P < 0.05). Providing 64 ml/day of PE tended (P = 0.06) to increase milk production by 11.64% and improve gross feed efficiency of cows by 12.04%. The PE supply did not influence milk composition and blood parameters of cows (P > 0.05). Offering 32 mL/day of PE decreased (P < 0.05) the rectal temperature and respiratory rate of cows. We recommend a supply of 64 mL/day of PE for heat-stressed dairy cows.

Transcriptomic profiles of the ruminal wall in Italian Mediterranean dairy buffaloes fed green forage

BACKGROUND

Green feed diet in ruminants exerts a beneficial effect on rumen metabolism and enhances the content of milk nutraceutical quality. At present, a comprehensive analysis focused on the identification of genes, and therefore, biological processes modulated by the green feed in buffalo rumen has never been reported. We performed RNA-sequencing in the rumen of buffaloes fed a total mixed ration (TMR) + the inclusion of 30% of ryegrass green feed (treated) or TMR (control), and identified differentially expressed genes (DEGs) using EdgeR and NOISeq tools.

RESULTS

We found 155 DEGs using EdgeR (p-values < 0.05) and 61 DEGs using NOISeq (prob ≥0.8), 30 of which are shared. The rt-qPCR validation suggested a higher reliability of EdgeR results as compared with NOISeq data, in our biological context. Gene Ontology analysis of DEGs identified using EdgeR revealed that green feed modulates biological processes relevant for the rumen physiology and, then, health and well-being of buffaloes, such as lipid metabolism, response to the oxidative stress, immune response, and muscle structure and function. Accordingly, we found: (i) up-regulation of HSD17B13, LOC102410803 (or PSAT1) and HYKK, and down-regulation of CDO1, SELENBP1 and PEMT, encoding factors involved in energy, lipid and amino acid metabolism; (ii) enhanced expression of SIM2 and TRIM14, whose products are implicated in the immune response and defense against infections, and reduced expression of LOC112585166 (or SAAL1), ROR2, SMOC2, and S100A11, encoding pro-inflammatory factors; (iii) up-regulation of NUDT18, DNAJA4 and HSF4, whose products counteract stressful conditions, and down-regulation of LOC102396388 (or UGT1A9) and LOC102413340 (or MRP4/ABCC4), encoding detoxifying factors; (iv) increased expression of KCNK10, CACNG4, and ATP2B4, encoding proteins modulating Ca²⁺ homeostasis, and reduced expression of the cytoskeleton-related MYH11 and DES.

CONCLUSION

Although statistically unpowered, this study suggests that green feed modulates the expression of genes involved in biological processes relevant for rumen functionality and physiology, and thus, for welfare and quality production in Italian Mediterranean dairy buffaloes. These findings, that need to be further confirmed through the validation of additional DEGs, allow to speculate a role of green feed in the production of nutraceutical molecules, whose levels might be enhanced also in milk.

Analysis of differentially expressed microRNAs in bovine mammary epithelial cells treated with lipoteichoic acid

Mastitis is one of the most common diseases of dairy cattle and can be caused by physical stress, chemicals and microbial infection. Staphylococcus aureus is the most common pathogens that induce mastitis in dairy cattle. In this study, bovine mammary epithelial cells (BMECs) were treated either with lipoteichoic acid (LTA, 30 µg/ml) or 1 × phosphate-buffer saline (PBS, control) and RNA-Seq was applied to explore the effect of LTA on the expression microRNAs (miRNAs) in BMECs. Compared to the control group, 43 miRNAs were significantly up-regulated and eight miRNAs were significantly down-regulated. Additionally, 724 genes were significantly up-regulated and 13 genes were significantly down-regulated in LTA group relative to the control group. Bta-miR-196a, bta-miR-2285aj-5p, bta-miR-143, bta-miR-2433, bta-miR-2284f and bta-miR-2368-3p were selected from 51 differentially expressed miRNAs and are discussed in this manuscript. Target gene prediction revealed that the target genes of these six miRNAs were all differentially expressed, including MT1E, SPDYA, FGL1, TLR2, PAPOLG, ZDHHC17 and SMC4. Subsequently, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the target genes with differentially expressed miRNAs were enriched in mitogen-activated protein kinase (MAPK) signalling pathway, rheumatoid arthritis and cancer. Therefore, the results of this study provided new evidences for the molecular mechanism of LTA-induced mastitis, which may provide new targets for the diagnosis and treatment of mastitis in dairy cattle.

16S rDNA sequencing combined with metabolomics profiling with multi-index scoring method reveals the mechanism of salt-processed Semen Cuscuta in Bushen Antai mixture on kidney yang deficiency syndrome

Kidney yang deficiency syndrome (KYDS) is a classic syndrome of traditional Chinese medicine (TCM). The salt-processed product of Semen Cuscuta (YP) is the monarch drug in Bushen Antai Mixture (BAM), can improve the reproductive dysfunction caused by KYDS, and the effect is better than that of raw products of Semen Cuscuta (SP). However, its mechanism is not completely clear yet. In this study, an integrated strategy combining untargeted metabolomics with microbiology was used to explore the mechanism of YP in the BAM improving KYDS. 16S rDNA gene sequencing showed that BAM containing YP (Y-BAM) had a significantly better regulatory effect on Desulfobacterota and Desulfovibrionaceae_unclassified than BAM containing SP (S-BAM). Untargeted metabolomics studies showed that Y-BAM significantly regulated 4 metabolites and 4 metabolic pathways. In addition, multi-index analysis showed that the effect of Y-BAM on arachidonic acid metabolism, tyrosine metabolism, purine metabolism, fructose and mannose metabolism and total metabolism was closer to that of the control group compared to S-BAM. The analysis of serum biochemical indexes showed that Y-BAM had more significant regulating effect on the levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T) and superoxide dismutase (SOD) in serum of KYDS rats compared to S-BAM. Spearman correlation analysis showed that there was a significant correlation between intestinal microorganisms and metabolites and serum biochemical indexes. For example, Desulfovibrionaceae_unclassified was positively correlated with arachidonic acid, and negatively correlated with SOD and LH. This study suggests that YP may enhance the regulation of intestinal flora and endogenous metabolism of KYDS, so that BAM shows a better therapeutic effect on KYDS, which also reasonably explains why BAM uses Semen Cuscuta stir-baked with salt solution.

Application of Chlorogenic acid as a substitute for antibiotics in Multidrug-resistant Escherichia coli-induced mastitis

Mastitis affects animal welfare and causes economic losses in the dairy industry. It is caused mainly by bacterial pathogens, among which Escherichia coli (E. coli) is one of the prominent causative agents. To treat bovine mastitis, antibiotics were widely used. However, their extensive and uncontrolled use has led to the emergence of multi-antibiotic-resistant strains. Indeed, a superbug of E. coli was successfully isolated from a mastitis-suffering cow and found resistant to at least 10 antibiotics. Therefore, the development of a universal therapeutic agent used as a replacement for the antibiotic is an immediate need in the dairy industry. To do so, we examined whether chlorogenic acid (CGA), a natural and herbal extract, could be a perfect alternative in mastitis treatment. In this study, we observed that the combination of CGA and antibiotic had an additive or synergistic effect; CGA fought against the superbug by directly targeting bacterial cell wall and membrane; CGA can significantly alleviate the mastitis caused by the superbug E. coli via its antimicrobial, antioxidant and anti-inflammatory activities. Collectively, these data indicated that CGA had a true potential to replace antibiotics during mastitis treatment.

Cysteamine Supplementation In Vitro Remarkably Promoted Rumen Fermentation Efficiency towards Propionate Production via Prevotella Enrichment and Enhancing Antioxidant Capacity

Cysteamine (CS) is a vital antioxidant product and nutritional regulator that improves the productive performance of animals. A 2 × 4 factorial in vitro experiment was performed to determine the effect of the CS supplementation levels of 0, 20, 40, and 60 mg/g, based on substrate weight, on the ruminal fermentation, antioxidant capacity, and microorganisms of a high-forage substrate (HF, forage:corn meal = 7:3) in the Statistical Analysis System Institute. After 48 h of incubation, the in vitro dry matter disappearance and gas production in the LF group were higher when compared with a low-forage substrate (LF, forge hay:corn meal = 3:7), which was analyzed via the use of the MIXED procedure of the HF group, and these increased linearly with the increasing CS supplementation (p < 0.01). With regard to rumen fermentation, the pH and acetate were lower in the LF group compared to the HF group (p < 0.01). However, the ammonia N, microbial crude protein, total volatile fatty acids (VFA), and propionate in the LF group were greater than those in the HF group (p < 0.05). With the CS supplementation increasing, the pH, ammonia N, acetate, and A:P decreased linearly, while the microbial crude protein, total VFA, and propionate increased linearly (p < 0.01). Greater antioxidant capacity was observed in the LF group, and the increasing CS supplementation linearly increased the superoxide dismutase, catalase, glutathione peroxidase, total antioxidant capacity, glutathione, and glutathione reductase, while it decreased the malondialdehyde (p < 0.05). No difference occurred in the ruminal bacteria alpha diversity with the increasing CS supplementation, but it was higher in the LF group than in the HF group (p < 0.01). Based on the rumen bacterial community, a higher proportion of Bacteroidota, instead of Firmicutes, was in the LF group than in the HF group. Furthermore, increasing the CS supplementation linearly increased the relative abundance of Prevotella, norank_f_F082, and Prevotellaceae_UCG-001 under the two substrates (p < 0.05). Prevotella, norank_f_F082, and Prevotellaceae_UCG-001 were positively correlated with gas production, rumen fermentation, and antioxidant capacity in a Spearman correlation analysis (r > 0.31, p < 0.05). Overall, a CS supplementation of not less than 20 mg/g based on substrate weight enhanced the rumen fermentation and rumen antioxidant capacity of the fermentation system, and it guided the rumen fermentation towards glucogenic propionate by enriching the Prevotella in Bacteroidetes.

Influence of breed, production system and fecundity on serum antioxidant profiles of goats reared in the tropical Island conditions

The present study assessed the physiological antioxidant status of goats reared under the humid tropical island ecosystem of the Andaman and Nicobar Islands (ANI). From 2019 to 2020, 25 multiparous non-pregnant does with three to six kidding records maintained in the organized farm of Central Island Agricultural Institute (CIARI) and farmer’s field flocks from South Andaman district were selected for the study. Antioxidant markers such as total antioxidant capacity (TAC), superoxide dismutase (SOD), TG (Total glutathione) and catalase (CAT) were analyzed in blood serum with respect to rearing systems, breeds and level of fecundity. Correlation analyses of all dependent variables were performed using Pearson’s correlation. The endogenous antioxidant systems, viz. CAT, TG and SOD was non-significant with respect to rearing systems, breeds and fecundity. Similarly, TAC was non-significant among the breeds and with fecundity; however, semi-intensively managed goats showed significantly higher values than goats under the extensive condition. Correlation analysis showed that CAT was positively correlated with SOD and negatively correlated with TAC. TG showed no correlation with any of the studied antioxidants. Regression analysis of CAT as dependent variable and SOD and TAC as independent variables showed significance. It is concluded that values of antioxidant in the study can be considered as a baseline data for the ALG and other goat breeds of Andaman and Nicobar Islands and other islands or topographies with similar ecosystems for further studies.

Preliminary Investigation of the Effects of Rosemary Extract Supplementation on Milk Production and Rumen Fermentation in High-Producing Dairy Cows

Rosemary extract (RE) has been used as an antioxidant in cosmetics and food additives, indicating its potential as a feed additive to improve adaptation in high-producing dairy cows. Here, we investigated the effects of RE supplementation on lactation performance and rumen fermentation in high-producing dairy cows. Thirty multiparous cows were blocked into 15 groups based on milk production and were randomly assigned to one of two treatments: 0 or 28 g/d of RE supplementation to the basic diet per cow. The experiment was conducted over a 74-day period, which included an initial two-week adaptation period. We observed significant increases in milk and milk lactose yields following RE supplementation. Somatic cell count tended to decrease by treatment. Additionally, superoxide dismutase concentration significantly increased and malonaldehyde level decreased after RE supplementation. Sequencing of 16S rRNA revealed that RE supplementation significantly affected the microbial composition and decreased the richness of the microbiota. Specifically, the abundance of the genus Prevotella was significantly decreased by RE supplementation and was correlated with volatile fatty acids in the Mantel test, whereas no significant correlation was found for other genera. Our findings provide fundamental information on the potential for RE as a feed additive for dairy cows to improve antioxidant status and enhance propionate generation.

Antioxidant Defences and Redox Homeostasis in Animals

For many years reactive oxygen species (ROS) production in biological systems has been considered to be detrimental [...]

Role of Selenium and Vitamins E and B9 in the Alleviation of Bovine Mastitis during the Periparturient Period

Mastitis (inflammation of the mammary gland) commonly occurs in dairy cattle during the periparturient period (transition period), in which dairy cattle experience physiological and hormonal changes and severe negative energy balance, followed by oxidative stress. To maintain successful lactation and combat negative energy balance (NEB), excessive fat mobilization occurs, leading to overproduction of reactive oxygen species (ROS). Excessive fat mobilization also increases the concentrations of nonesterified fatty acids (NEFA) and β-hydroxybutyric acid (BHB) during the periparturient period. In addition, the excessive utilization of oxygen by cellular respiration in the mammary causes abnormal production of oxidative stress (OS). OS impairs the immunity and anti-inflammatory efficiency of periparturient dairy cattle, increasing their susceptibility to mastitis. To alleviate oxidative stress and subsequent mastitis, antioxidants are supplemented to dairy cattle from an external source. Extensive studies have been conducted on the supplementation of selenium (Se) and vitamins E and B9 to mitigate mastitis during the transition period in dairy cattle. Altogether, in the current review, we discuss the research development on bovine mastitis and its major causes, with special emphasis on oxidative stress during the transition period. Moreover, we discuss the antioxidant, immunoregulatory, and anti-inflammatory properties of Se and vitamins E and B9 and their role in the control of bovine mastitis in periparturient dairy cattle.