Prototheca microalgae were only recognized as pathogens of both humans and animals in the 1960s; however, since then, these microbes have been drawing increasing interest in both human and veterinary medicine. The first human outbreak of protothecosis in a tertiary care chemotherapy ward in 2018 further highlighted the need to understand in more depth and detail their ecology, etiology, pathogenesis and routes of transmission between different hosts, environments and habitats from a One Health perspective. Protothecal infections have been reported in a growing number of cattle herds around the world in recent decades, and Prototheca has become an important bovine mastitis pathogen in certain countries and regions. The survival of Prototheca in the environment and its ability to spread in the herd pose a serious challenge to the management of infected dairy farms. Prevention of the disease is particularly important, as there is no effective and reliable treatment for it and the chances of self-healing are minimal. Therefore, the development of more effective drugs is needed for the treatment of human and animal protothecosis. The prudent use of antibiotics and their replacement by alternative or preventive measures, when possible, may further contribute to the control of protothecal infections.

The aim of the study was to determine the effect of cow breed, season and type of diet on the fatty acid (FA) profile of raw milk. A 2-year study was conducted on bulk milk samples collected from eight herds consisting of Czech Fleckvieh (CF, four herds) and Holstein (H, four herds) breeds. One half of the herds of each breed was grazed (G), while the other half was not (N). Samples were collected twice in winter (W) and twice in summer (S). Milk yield in CF (5385.50 kg) was lower than in H (7015.15 kg, P < 0.05). The effect of breed was found in odd-chain, branch-chain and hypercholesterolemic FAs (P < 0.05). The content of fat was lower in summer (S) than in winter (W), being 3.71 and 3.91 g 100 g⁻¹, respectively (P < 0.05). The proportion of saturated and polyunsaturated FAs was lower in S than in W (P < 0.05). The content of monounsaturated FAs was higher in S (30.69 g 100 g⁻¹) than in W (27.72 g 100 g⁻¹, P < 0.05). Milk yield in grazing herds (G, 5197.50 kg) was lower (P < 0.05) than in non-grazing herds (N, 7203.75 kg). The sum of saturated and hypercholesterolemic FAs was lower and the sum of monounsaturated and odd-chain FAs was higher in G than in N (P < 0.05). Content of conjugated linoleic acid (CLA) and C18:3n3 was higher in G (0.93 and 0.64 g 100 g⁻¹) than in N (0.42 and 0.39 g 100 g⁻¹, respectively, P < 0.001).

In a return to tradition, the popularity of caprine milk is on the rise. However, particularly in countries with developed dairy industries based on bovine milk, there is the risk of adulteration with bovine milk, which is a cheaper alternative. Thus, a rapid, robust, and simple method for the detection of bovine milk added to caprine milk is necessary, and ¹H nuclear magnetic resonance spectroscopy appears to provide a solution. A matrix of 115 pure and artificially adulterated pasteurized milk samples was prepared and used to discover biomarkers of bovine milk that are independent of chemical and biological variation caused by factors such as genetics, diet, or seasonality. Principal component analysis and orthogonal projections to latent structures discriminant analysis of pure bovine milk and pure caprine milk revealed spectral features that were assigned to the resonances of 4 molecules. Of these, the peaks corresponding to protons in the N-acetylglucosamine and N-acetylgalactosamine acetyl moieties showed significant applicability for our method. Receiver operating characteristic curve analysis was used to evaluate the performance of the peak integrals as biomarkers of adulteration. This approach was able to distinguish caprine milk adulterated with 5% of bovine milk with 84.78% accuracy and with 10% of bovine milk an excellent 95.65% accuracy. This study demonstrates that N-acetyl carbohydrates could be used as biomarkers for the detection of bovine milk in caprine milk and could help in protecting caprine milk authenticity.

The study focused on the prevalence of Staphylococcus aureus and resistant strains in livestock. In this study, 114 different samples from three cattle farms (84 from two farms of dairy cows and 30 from one farm of suckler cows), 132 samples from one sheep farm, 120 samples from one goat farm, and 82 samples from three pig farms were examined. Strains identified as Staphylococcus aureus were further analysed by the polymerase chain reaction method for detection of the mec A gene and for confirmation of the sequence type 398. Positive incidence of Staphylococcus aureus was confirmed in farms of suckler cows, sheep, goats and pigs. The incidence of methicilin-resistant Staphylococcus aureus was confirmed at a goat farm, with all strains belonging to the sequence type 398. Repetitive element palindromic-polymerase chain reaction analysis was performed to compare the relatedness of selected human and animal S. aureus strains at the goat and sheep farms. The obtained data from repetitive element-polymerase chain reaction analysis showed significant clonal similarity among the tested isolates and indicated the possibility of mutual transmission between animals or animal and human and possible transfer in the food chain.

Rapid analytical methods can contribute to the expansion of milk fatty acid determination for various important practical purposes. The reliability of data resulting from these routine methods plays a crucial role. Bulk and individual milk samples (60 and 345, respectively) were obtained from Czech Fleckvieh and Holstein dairy cows in the Czech Republic. The correlation between milk fatty acid (FA) proportions determined by the routine method (infrared spectroscopy in the mid-region in connection with Fourier transformation; FT-MIR) and the reference method (gas chromatography; GC) was evaluated. To validate the calibration of the FT-MIR method, a linear regression model was used. For bulk milk samples, the correlation coefficients between these methods were higher for the saturated (SFAs) and unsaturated FAs (UFAs) (r = 0.7169 and 0.9232; p < 0.001) than for the trans isomers of UFAs (TFAs) and polyunsaturated FAs (PUFAs) (r = 0.5706 and 0.6278; p < 0.001). Similar results were found for individual milk samples: r = 0.8592 and 0.8666 (p < 0.001) for SFAs and UFAs, 0.1690 (p < 0.01) for TFAs, and 0.3314 (p < 0.001) for PUFAs. The correlation coefficients for TFAs and PUFAs were statistically significant but too low for practical analytical application. The results indicate that the FT-MIR method can be used for routine determination mainly for SFAs and UFAs.

Heat stability (HS) is substantial technology property of raw milk. Analysis of sources of HS variation and its regular monitoring can contribute to creating higher added value in the dairy industry. The goal of this analysis was to assess the practice sources of raw cow milk HS variability on the results of an extensive data set of bulk tank milk samples. There was implemented neither a compositional technology modification nor acidity adjustment of milk, just original raw milk was used for the analysis. A total 2634 HS analyses were performed, including other milk indicators, during three years of an experimental period. The log HS mean and standard deviation were 1.273654 ± 0.144189, equal to the HS geometric mean of 18.8 min. Explanation of the HS variability through the linear model used was 41.1% (p < 0.0001). According to the results of the variance analysis, the milk HS was influenced (p = 0.0033 and mostly <0.0001) by all the farm factors such as year; season; calendar month; altitude; total annual rainfall; herd size by the number of cows; milk yield; cow breed; type of milking; litter type in the stable; summer grazing application; farm effect. During the calendar months (p < 0.0001), milk HS values suggest similar seasonal dynamics with the somatic cell count, total count of mesophilic microorganisms, coli bacteria count and urea and lactose concentration and opposite configuration pattern to fat, crude protein, solids-not-fat and total solids content and milk freezing point depression. Here performed quantification of these effects by analyzing the variance may allow efficient raw milk selection to be processed into specific dairy products.