The aim of this study was to determine changes of reactive oxygen species (ROS), serum antioxidant capacity (SAC), oxidative stress index (OSi), and α-tocopherol (α-T) during the periparturient period in healthy and mastitic cows and to further investigate whether these parameters can be used as a tool for identifying cows at higher risk of developing mastitis. Blood samples from 110 dairy cows from two commercial farms were obtained at dry-off, calving, and 30 days post-partum. Healthy cows formed group A (n = 90) and mastitic cows B (n = 20). Blood serum was obtained by centrifugation, and the aforementioned parameters were determined. A general linear model was used for analysing the associations among the determined blood parameters, the health of the animals’ udder, and the sampling time. ROS and OSi values were higher (P < 0.001) by a respective 14% and 26%, and SAC values lower (P < 0.001) by 10% in group B than in group A at calving. ROC curve analysis revealed that all determined parameters at calving and α-T at dry-off and 30 days post-partum had excellent or acceptable predicting ability for mastitis incidence. This information provides a tool for early identification of cows at high risk of developing mastitis, allowing the implementation of intervention strategies.

Bovine mastitis is an inflammatory disease of the udder that causes important economic losses in the animal breeding and dairy product industries. Nowadays, the conventional livestock antibiotic treatments are slowly being replaced by alternative treatments. In this context, the main aim of this study was to evaluate the efficacy of natural products in alternative treatment of bovine mastitis. Two natural formulations with previously suggested in vitro antimicrobial effect were tested in vivo on mastitic cows. Animals with a positive diagnosis for mastitis (n = 20) were divided into three treatment groups: two groups (n = 8) were administered formulations of propolis, alcoholic extracts of Brewers Gold and Perle hops, plum lichen, common mallow, marigold, absinthe wormwood, black poplar buds, lemon balm, and essential oils of oregano, lavender, and rosemary designated R4 and R7 (differing only in the latter being more concentrated) and one group (n = 4) a conventional antibiotic mixture. In vivo efficacy of treatments was evaluated by somatic cell and standard plate counts, the treatment being considered efficacious when both parameters were under the maximum limit. R7 was effective in the most cases, being therapeutically bactericidal in six out of eight cows, while R4 gave good results in three out of eight cows, and conventional antibiotics cured one out of four. These results suggest the possible therapeutic potential of these natural products in bovine mastitis.

Objective: The objective of this study was to investigate the intensity of phage infection caused by Phage SAvB14, which was isolated from dairy farms, depending on the initial number of Staphylococcus aureus cells in the medium. Material and methods: To evaluate the impact of the viable bacteria S. aureus var. bovis on the intensity of phage infection caused by Phage SAvB14, 1 mg of phagolysate (phage titer 105 CFU/ ml) was introduced in 9 ml of nutrient broth with an appropriate amount of daily culture of S. aureus var. bovis under study. The number of viable staphylococci was determined by total viable count/ml. Results: In this experiment, we found that the intensity of phages lytic activity was dependent on the number of sensitive bacterial cells in the volume of the culture medium. Effective phage ther¬apy requires a high concentration of phages in the medium (inflammation foci) for rapid contact of the virus with bacteria. Conclusion: When developing a phage drug to treat subclinical mastitis, it is necessary to increase the phage titer in the drug or its dosage compared to the clinical form, as there is a lower proba¬bility of phage contact with a susceptible microbial cell. Besides, at a high concentration of bacte¬ria, there is a gradual decrease in nutrients in the medium, resulting in phages going back to the condition of lysogeny. [J Adv Vet Anim Res 2020; 7(3.000): 509-513]