Mastitis is considered to be one of the most important diseases of dairy cows in terms of health, production, and economy. Being the most common cause of antibiotic consumption in dairy cows, treatment of this disease is one of the biggest challenges in the veterinary profession as an increasing number of pathogens develop resistance to antibiotics used in the treatment. Therefore, new alternative approaches for limiting the use of antibiotics in livestock are required. For this reason, our study aimed to investigate prevalence of environmental mastitis associated bacterial strains, as well as the sensitivity of isolated strains to different antibiotics. Additionally, the therapeutic potential of three essential oils (EOs) was tested against bovine Serratia spp. and Proteus spp. mastitis pathogens, based on their chemical composition, as well as antibacterial potential. The study was carried out on 81 milk samples collected from dairy cows with mastitis. In order to determine prevalence of S. marcescens and P. mirabilis, microbiological isolation and identification were performed. Antimicrobial susceptibility testing was performed by disk diffusion method and the microdilution method was used to determine the antibacterial activity of selected EOs. In the oregano EO, a total of 23 compounds were detected, with carvacrol as a dominant component (78.94%). A total of 26 components were present in the EO of common thyme, where thymol was the most abundant compound (46.37%). Thymol also dominated (55.11%) the wild thyme EO. All tested EOs displayed antibacterial activity against all strains to different extents, while wild and common thyme EOs were the most effective. It could be concluded that the tested EOs represent promising therapeutic candidates for effective non-antibiotic treatment of mastitis.

Increasing pressure on animal and human health as well as food security, due to antimicrobial resistance, is leading to increased demand for natural-product-derived antibiotics worldwide. Considering the importance of bovine mastitis as well as the huge challenge posed by mastitis therapy in cattle production, the main goal of this research was to evaluate the effectiveness of the essential oil-based pharmaceutical (Phyto-Bomat), as an alternative to the existing treatment with antibiotics. The therapeutic response of the cows was monitored using clinical and bacteriological cure of the proposed formulation. Among 550 dairy cows, 75 were diagnosed with a clinical or subclinical form of mastitis and divided into three experimental groups: treated with antibiotic; Phyto-Bomat; antibiotic and Phyto-Bomat. Indicators of bacteriological cure were somatic cell count (SCC), total bacterial count, and causative agent isolation, while the clinical cure was accessed by observing physical udder conditions. All mentioned indicators were assessed before and after the treatment (1st and 7th day post-treatment), with all of the three therapeutic protocols. After Phyto-Bomat treatment, no visible signs of irritation were noticed, while no significant effect in reducing SCC and total bacterial count was observed. Phyto-Bomat has shown promising results in the treatment of mastitis, without the risk of udder irritation, alone or in combination with antibiotics as part of a mastitis control program during lactation.

Due to the emergence of antibiotic-resistant bacteria, the risk it represents to public health, and the possible consequences for animal health and welfare, there is an increasing focus on reducing antimicrobial usage (AMU) in animal husbandry. Therefore, a great interest in developing alternatives to AMU in livestock production is present worldwide. Recently, essential oils (EOs) have gained great attention as promising possibilities for the replacement of antibiotics. The current study aimed to test the potential of using a novel EO-based pharmaceutical formulation (Phyto-Bomat) in bovine mastitis treatment. The antibacterial activity was performed using the microdilution technique. Lactating dairy cows were treated with 15 mL of Phyto-Bomat in the inflamed quarter for 5 consecutive days in order to analyze blood and milk samples for thymol and carvacrol residues using gas chromatography and mass spectrometry (GC–MS). Antimicrobial activity expressed as the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) indicates that this formulation has the highest activity against Gram-positive strains. The dominant compounds in Phyto-Bomat were thymol and carvacrol, at 12.58 ± 1.23 mg/mL and 23.11 ± 2.31 mg/mL, respectively. The quantification of these two compounds in evaluated biological samples showed that 24 h after administration the concentration of thymol and carvacrol in milk samples was at the same level as before application. On the other hand, thymol and carvacrol were detectable in plasma samples even after 24 h post-treatment, with values ranging from 0.15–0.38 and 0.21–0.66 µg/mL, respectively. The tested formulation showed encouraging results of antibacterial activity against bovine mastitis pathogens, as well as the withdrawal period of dominant compounds, which implies that further testing regarding the bacteriological and clinical cure rates in clinical settings is needed.

Inflammation of the mammary gland alters substrate utilization and metabolite trafficking between the systemic circulation and mammary tissue, leading to metabolic adaptations that affect udder function and milk composition. This study investigated mammary metabolic alterations in dairy cows with different udder health statuses by evaluating mammary venous biomarkers (MV), coccygeal-to-mammary vein (CV/MV) concentration ratios, and their associations with milk quality indicators. Sixty Holstein cows were assigned to clinical mastitis, subclinical mastitis, or healthy control groups (n = 20/group). Milk samples were analyzed for somatic cell count (SCC), bacterial load (CFU), and lactose concentration, while blood samples were analyzed for metabolic, enzymatic, and mineral biomarkers, and CV/MV ratios were calculated. Clinical mastitis was associated with reduced MV concentrations of glucose, triglycerides, and calcium and increased concentrations of NEFA, β-hydroxybutyrate, total protein, globulin, urea, bilirubin, and LDH activity. Compared with healthy cows, clinically mastitic cows also showed distinct CV/MV patterns, with ratios > 1 for NEFA, β-hydroxybutyrate, total protein, globulin, AST, urea, and magnesium and <1 for glucose, triglycerides, albumin, ALT, ALP, LDH, and calcium. These shifts in CV/MV ratios demonstrate altered relationships between systemic and mammary venous metabolic profiles across udder health statuses. Principal component analysis clearly separated clinically mastitic cows from healthy animals based on MV biomarkers and CV/MV ratios, whereas subclinical mastitis showed an intermediate metabolic profile. Among the evaluated biomarkers, LDH showed the strongest associations with SCC, CFU, and milk lactose concentration, highlighting its potential as an indicator of intramammary inflammation and tissue injury. The primary novelty of this study is the demonstration that CV/MV ratios provide an additional, potentially useful tool for monitoring mastitis-associated mammary metabolic alterations by capturing changes in the relationship between systemic and mammary venous metabolism. Combining mammary venous metabolic profiling with CV/MV ratios therefore provides complementary information for improved characterization of udder health status in dairy cows.