This study investigated 960 Slovak and Czech spotted cattle from four different conventional (non-organic) dairy herds located in Eastern Slovakia and Czechia during early lactation (14–100 days after calving). Dairy cows were examined clinically; milk from fore-stripping of each udder quarter was subjected to sensory examination and assessed by the California mastitis test (CMT), and laboratory analyses of bacterial pathogens in milk, including virulence factors, were conducted. Positive CMT scores (1–3) for one or more quarters were detected in 271 (28.2%) of the examined animals. Out of 230 infected milk samples, representing 24.0% of all dairy cows, staphylococci (59.1% of positive findings) were the most commonly isolated organisms, followed by E. coli (11.3%), streptococci Str. uberis (9.1%) and Str. agalactiae (3.4%), and enterococci (6.1%). From 136 isolates of S. aureus (38 isolates) and non-aureus staphylococci (NAS; 98 isolates), virulence factors and their resistance to 14 antimicrobials were detected using the disk diffusion method, with PCR detection of the methicillin resistance gene, mecA. An increased incidence of clinical and chronic forms of mastitis has been reported in mastitic cows in which staphylococci, especially S. aureus and NAS (S. chromogenes, S. warneri, and S. xylosus), have been detected and compared to other isolated udder pathogens. From those species, S. aureus and isolates of NAS mentioned above showed multiple virulence factors that are more likely to hydrolyze DNA, hemolysis, produce gelatinase and biofilm, and have multi-drug resistance as compared to other less virulent staphylococci. Generally, the isolated staphylococci showed 77.2% resistance to one or more antimicrobials, in particular to aminoglycosides, β-lactams, macrolides, or cephalosporins. Isolates that showed the ability to form a biofilm were more resistant to more than one antimicrobial than isolates without biofilm production. Multi-drug resistance to three or more antimicrobial classes was recorded in 16 isolates (11.7%), and the presence of the mecA gene was also confirmed in two isolates of S. aureus and two species of NAS.

This study was conducted to evaluate the incidence of mastitis in 153 dairy cows and to evaluate the kinetics of adhesion of isolates obtained from surfaces and milk in comparison with the reference strain (RS), CCM 4223. The surfaces of the floor, teat cup, and cow restraints were aseptically swabbed in three replicates (n = 27). Of the total number of infected cows (n = 43), 11 samples were found to be positive for Staphylococcus aureus, 12 samples tested positive for non-aureus staphylococci, 6 samples tested positive for Streptococcus spp., and 11 samples tested positive for other bacteria (Escherichia coli, Pseudomonas spp.) or a mixed infection. The most represented pathogen in milk (11/43) and on surfaces (14/27) was S. aureus. The kinetics of adhesion of the reference strain and isolates of S. aureus on stainless steel surfaces were determined after 3, 6, 9, 12, 24, and 48 h, and 3, 6, 9, 12, and 15 days of incubation. All strains reached counts higher than 5 Log₁₀ CFU/cm² needed for biofilm formation, except RS (4.40 Log₁₀ CFU/cm²). The isolates of S. aureus revealed a higher capability to form biofilm in comparison with RS during the first 3 h (p < 0.001). Thus, there is a significant difference between the occurrence of S. aureus on monitored surfaces—floor, teat cup, and cow restraints—and the frequency with which mastitis is caused by S. aureus (p < 0.05). This finding raises the possibility that if various surfaces are contaminated by S. aureus, it can result in the formation of biofilm, which is a significant virulence factor.

The aim of this study was to compare three on-farm commercial methods for the indirect detection of subclinical mastitis in dairy cows: the California mastitis test (CMT), the Porta side somatic cell count milk test (Porta SCC), and the DeLaval cell counter (DCC), with the Fossomatic cell count (FSCC), and to evaluate the relationship between the determined somatic cell count SCC and the occurrence of intramammary pathogens in the milk of dairy cows. A total of 284 sensory unchanged mixed milk samples, collected during the milking on a dairy farm, were analyzed in this study for somatic cell counts by the mentioned on-farm tests. Quarter milk samples (n = 583) from all the selected cows were cultured. The agreement, sensitivity, and specificity of the three indirect commercial diagnostic tests (the CMT, the Porta SCC, and the DeLaval cell counter) were calculated, and the FSCC was used as the gold standard. The results were analyzed statistically using the Pearson correlation test and the paired t-test. The CMT matched with the FSCC in 83.1% of the samples, with the Porta SCC in 80.6%, and with the DCC in 80.3% of the samples. The sensitivity and specificity reached 81.0% and 92.9% for the CMT, 79.4% and 90.7% for the Porta SCC, and 75.8% and 97.5% for the DCC, respectively. The correlation between the FSCC and the Porta SCC was 0.86 (p < 0.0001), and between the FSCC and the DCC, it was 0.92 (p < 0.0001). The differences between them were insignificant. Bacteria were detected in 130 (22.3%) quarter milk samples. The most prevalent bacteria were Enterococcus spp. (36.2%), followed by E. coli (20%), coagulase-negative staphylococci (13.1%), A. viridans (9.2%), Streptococcus spp. (9.2%), Proteus spp. (6.2%), and S. intermedius (3.9%). Contagious isolates (S. aureus) were detected in 3 quarter milk samples (2.3%). The agreement between the individual tests and the microbiological culture was as follows: 69.2% for the CMT; 73.7% for the Porta SCC; 71.6% for the DCC; and 76.5% for the FSCC. Higher SCCs were detected in the milk samples contaminated with bacteria than in the healthy milk (p < 0.001). No significance was found between the presence of individual species of intramammary pathogens and the different levels of SCCs. Based on the results, bacteria are the predominant cause of subclinical mastitis. The increased SCC of some milk samples with no presence of bacteria meant that the increase could have been caused by numerous other agents (viruses, fungi, or algae) or factors for mastitis in the dairy industry.

This study focuses on the effect of parenteral administration of Selenium (Se) and vitamin E on concentration of Se in plasma and the activity of glutathione peroxidase (GPx) in the blood of dairy cows during peripartal period and their effect on the reduction of clinical mastitis. From a 220 individuals Holstein herd in a two-four lactation-gestation cycle the control group (C), 1st (D1) and 2^nd (D2) experimental group were selected. Every group consisted of 15 cows in the last phase of the pregnancy. All cows were fed with the diet containing 0.1 mg of Se per kg/DM. The blood samples from vena jugularis were collected approximately 21 days before calving (control sampling), 3 days, 12 days and 21 days after calving. On the day of control sampling and 12 days before calving in D1 group, cows were injected subcutaneously in the sprescapular region with preparation Selevit inj. a.u.v. at the doses of 48.4 mg/head of Se, and 550 IU/head of α-Tocoferol (α-Toc). In D2 group, cows were injected by the same preparation only on 21^th day before calving with the same doses of Se and α-Toc. The increase in the concentration of Se in the plasma and activity GPx in blood in D1 group on the 3rd day and 12^th day after calving were determined. Increase in plasmatic concentrations α-Toc on 3^rd day after calving and reduction of occurrence of clinical mastitis (13.3%) as compared with control group were found

In this study, we assessed the effect of humic substances, as an organic supplement in feed, on the fattening performance, meat quality and selected lipid and mineral parameters from the blood serum of rabbits. Three groups of the Giant Saris rabbit breed were used (one control and two experimental), with 16 animals per group. The animals in the control group were fed a standard pellet diet, the humic substances group received a basal diet supplemented with 5% humic substances, and the third group received a basal diet with 5% humic–fatty substances preparation during the entire experiment (from 35 to 120 days of age). There were 85 days of fattening; then, the rabbits were slaughtered. In the group supplemented with 5% humic–fatty substances addition, we noticed a higher final weight (p < 0.05) and higher average daily gains compared to the control group at the end of the fattening period, at 120 days of age. On the other hand, a slightly lower final weight (p > 0.05) in the group supplemented with humic substances was found compared to the control group. In the comparison of the individual parameters of the meat quality in rabbits, we observed a positive effect in the reduction in the intramuscular fat content and the lipid parameters as well as a lower total cholesterol from the blood serum in both supplemented groups. Regarding the mineral parameters, we observed elevated blood serum values of calcium and phosphorus in both experimental groups. The addition of humic–fatty substances appears to be the most effective way of supplementing rabbit feed due to the synergistic effect of humates and vegetable oils for their optimal growth development and the production of reduced-fat meat.

Introduction and objective: Correlations between the number of milk somatic cells (SCC), the number of microorganisms, and the content of basic components of milk were studied on five farms (F1–F5) with cows of the same breed, but with different milking systems. Material and methods: From...