M. SAMARDŽIJA: Bovine mastitis: a persistent and evolving problem requiring novel approaches for its control -a review. Vet. arhiv 88, 535-557, 2018. ABSTRACT Mastitis in dairy cows is the inflammation of the mammary gland, and is the most important cause of economic losses in the modern dairy industry. Bovine mastitis is often infectious and can be caused by some 150 microbial species. The environment of the dairy cow is heavily colonized by microbiota, while milk is an ideal medium for propagation of the bacteria and causative agents. Staphylococcus aureus is the most common pathogen isolated from the mammary gland capable of causing health disorders in humans. Milk from an infected mammary gland has a different chemical composition compared to milk from healthy cows. Certain differences, such as protein components specific to inflamed tissue, are currently being considered in 2018 M. Benić et al.: Bovine mastitis: a persistent and evolving problem requiring novel approaches for its control the development of diagnostic tools for mastitis. The known risk factors for mastitis can result in mastitis at the quarter, cow and herd levels. Mastitis treatment includes both preventive and therapy measures, and is primarily based on the use of antibiotics. Recent approaches to mastitis therapy have been focused on the design and use of natural therapeutics, such as zeolites, ozone and propolis, that could serve as alternatives to antibiotics.

Biogenic amines (BAs) are considered a potential microbiological toxicological hazard in aged cheese. Risk mitigation strategies include good hygiene practice measures, thermal treatment of milk and the use of competitive dairy cultures. The aim of this study was to evaluate the amount of BAs—tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine—in the core and rind of cheeses ripened by bacteria (n = 61) and by mold cultures (n = 8). The microbial communities were counted, and the dominant lactic acid bacteria (LAB) were identified, corresponding to the BA concentrations. The total BA content was highest in the core of semi-hard cheeses (353.98 mg/kg), followed by mold cheeses (248.99 mg/kg) and lowest in hard cheeses (157.38 mg/kg). The highest number of BAs was present in the rind of cheeses with mold (240.52 mg/kg), followed by semi-hard (174.99 mg/kg) and hard cheeses (107.21 mg/kg). Tyramine was the most abundant BA, represented by 75.4% in mold cheeses, 41.3% in hard cheese and 35% of total BAs in semi-hard cheeses. Histamine was present above the defined European maximum level (ML) of 100 mg/kg in only two semi-hard and three hard cheeses. High amount of BAs (above 600 mg/kg) in cheeses, mainly tyramine, were associated with the presence of Enterococcus durans, while negligible BA concentrations were found in cheeses ripened with Lacticaseibacillus rhamnosus, Lactococcus lactis or Lacticaseibacillus paracasei cultures. This study has shown that retailed cheese varieties produced with commercial bacterial or mold cultures have acceptable levels of biogenic amines with respect to consumers.

Crossbreeding of Holstein cattle with bulls of other breeds has garnered increasing interest with respect to efforts to improve performance traits and to decrease problems with fertility and health. Therefore, the objective of this study was to compare the effects of the fatty acid synthase (FASN) gene on milk production traits and fatty acid composition of Simmental and first-generation Holstein × Simmental crossbred cows. A total of 105 cows (72 Simmental and 33 crossbred Holstein) were genotyped using the PCR-RFLP method and their fatty acid profiles were analysed. The crossbred Holstein cows with diplotype TW/AR had significantly higher fat content and yield compared to the purebred Simmental cows of the same diplotype. The Holstein × Simmental cows with the diplotype AR/AR were also characterised by significantly lower content of C16:0 and saturated fatty acids, but higher C18:1n9, monounsaturated fatty acid and monounsaturated fatty acid/saturated fatty acid content compared to the same diplotype of the Simmental cattle. These results indicate that with accurate breeding plans, crossbreeding Holstein cows with Simmental bulls could be directed towards a more desirable fatty acid composition of milk and dairy products.

Hercegovački pršut as a traditional dry-cured smoked ham (prosciutto) produced by using an open fire that can be potentially contaminated with polycyclic aromatic hydrocarbons (PAHs) and can pose a health risk for consumers. The aim of this research was to identify the types and concentrations of 16 PAHs in 34 samples of traditionally smoked prosciutto. Out of 16 investigated PAHs, identified in the EPA (Environmental Protection Agency) list of priority pollutants, 14 compounds were detected. Average levels of cancerogenic benzo[a]pyrene (BaP) and PAH4 (benzo[a]anthracene (BaA), benzo[b]fluoranthene (BbF), chrysene (Chry), and benzo[a]pyrene (BaP)) ranged from <LOQ (level of quantification) to 5.08 μg/kg and 0.45 μg/kg to 22.67 μg/kg. Two analyzed samples exceeded currently prescribed values according to the Bosnia and Herzegovina legislation for BaP concentrations and one sample for PAH4 content. PAH16 concentrations were on average between 2.92 μg/kg and 87.6 μg/kg. The highest PAH concentrations were found in samples from the Herzegovina-Neretva canton. The results of the research highlight the importance of standardizing smoking procedures and manufacturing practice, in the production of Hercegovački pršut, in order to reduce the PAH content.

This study aimed to investigate the climatical impacts of air temperature, sunlight duration, and rain precipitation, in a moderate climate, on the reproductive performance of Romanov sheep in the continental part of Croatia, during two consecutive years (2019-2020).