Zoran Ružić

Antimicrobial resistance in avian pathogenic Escherichia coli (APEC) poses a significant challenge to poultry production, highlighting the need for effective alternatives to conventional antimicrobials. This study aimed to evaluate the antibacterial activity of selected essential oils (EOs) against multidrug-resistant APEC isolates and assess the in vivo effects of an oregano–thyme EO-based formulation in experimentally infected broilers. Six EOs were screened in vitro using the broth microdilution method, and oregano and thyme EOs, showing the strongest activity (MIC 0.003% and 0.003–0.007%, respectively), were further evaluated in two combinations. The more active combination was formulated for administration via drinking water and tested in 420 Ross 308 broilers experimentally challenged with APEC. Birds were allocated to untreated control, infected untreated, EO-treated, enrofloxacin-treated, and enrofloxacin + reduced-dose EO formulation groups. Mortality did not differ significantly among groups. A binomial GLMM identified significant differences in faecal consistency among experimental groups (likelihood-ratio χ² = 32.90, df = 4, p < 0.001), while no significant differences were observed in body weight, feed intake, or overall FCR. Significant differences were detected in AST, glucose, total bilirubin, and calcium concentrations. Overall, the EO-based formulation demonstrated antibacterial activity in vitro and was associated with changes in intestinal status following APEC challenge, while no consistent improvement in productive performance was observed. These findings support further investigation of EO-based formulations as potential non-antibiotic approaches for managing APEC-associated intestinal disturbances in broiler chickens.

Litter quality is a key factor influencing broiler welfare, particularly footpad health, yet the effects of loose versus pelleted natural litter formulations are not fully understood. This study assessed the impact of six treatments, composed of wheat straw, wood shavings, and peat in loose or pelleted forms, on litter moisture, pH, and footpad lesions during a 42-day fattening period. Litter condition was monitored weekly through scoring, moisture content, and pH measurements, while footpad integrity was assessed on a weekly basis throughout the fattening period. Loose litter exhibited higher moisture accumulation, greater pH variability, and earlier onset and more severe footpad lesions compared to all pelleted materials as well as wood shavings, which maintained more stable conditions and delayed lesion development. The initial physical properties and formulation of the litter materials contributed to these differences, with coarser textures potentially contributing increased mechanical stress on the footpads. Litter pH values converged and stabilized toward the end of the production cycle across all treatments. These results demonstrate that both litter composition and form significantly influence litter conditioning and broiler welfare. Careful selection and management of natural litter, with attention to moisture retention and pH stability, are essential to reduce footpad dermatitis and support optimal performance in intensive broiler production.

Konzumna jaja su značajna namirnica animalnog porekla, a procena njihove bezbednosti zahteva razumevanje nekoliko važnih činilaca. Cilj rada bio je da se proceni znanje potrošača u Srbiji o aspektima bezbednosti konzumnih jaja, sa osvrtom na rezidue veterinarskih lekova, pranje i dezinfekciju, rizik od Salmonella spp. i uticaj različitih sistema držanja nosilja na bezbednost jaja. Istraživanje je sprovedeno 2025. godine putem anonimnog upitnika na uzorku od 393 ispitanika. Upitnik je obuhvatio pitanja o kupovnim navikama, rukovanju jajima, proceni mikrobioloških i hemijskih rizika i stavovima o sistemima proizvodnje. Rezultati su ukazali na neujednačenu informisanost potrošača o hemijskim i mikrobiološkim aspektima bezbednosti. Prisustvo rezidua antibiotika kao moguć nalaz prepoznalo je 61,1% ispitanika, pri čemu je 56,7% smatralo da one mogu predstavljati opasnost po zdravlje ljudi. Mogućnost prisustva rezidua antiparazitskih lekova navelo je 56,2% ispitanika, a teških metala 50,1%. U pogledu higijenskog tretmana jaja pre stavljanja u promet, 61,6% ispitanika nije bilo sigurno da li se jaja Peru i dezinfikuju pre prodaje, dok je 20,4% smatralo da se ovaj postupak sprovodi uvek ili povremeno. Zaprljana jaja kao potencijalni rizik za prenošenje patogena prepoznalo je 52,4% ispitanika. Tvrdnju da se pranjem jaja patogeni sa ljuske mogu potisnuti u unutrašnjost jaja podržalo je 33,1% ispitanika, a 26,5% je bilo neutralno. Da je uz redovne kontrole nadležnih institucija rizik od infekcije izazvane Salmonella spp. minimalan, smatralo je 53,4% ispitanika, dok je 24,7% smatralo da značajan rizik i dalje postoji. Tvrdnju da su dobrobit nosilja i bezbednost jaja u direktnoj vezi podržalo je 52,9% ispitanika, dok je 48,6% negiralo da slobodni sistem uzgoja predstavlja veći rizik za prenošenje patogena. Dobijeni rezultati ukazuju na neujednačeno razumevanje higijenskih i hemijskih aspekata bezbednosti konzumnih jaja i potvrđuju potrebu za ciljanom edukacijom potrošača, u kojoj veterinari imaju važnu ulogu kroz stručno informisanje o objektivnim pokazateljima bezbednosti hrane animalnog porekla.

This review explores the potential role of androgens in human breast cancer and female canine mammary tumors. Human breast cancer is one of the most common cancers affecting women globally, while female canine mammary tumors provide a natural model for the study of human breast cancer due to their similar histopathologies and molecular features. Androgen receptors, typically linked to male sex hormones, are present in up to 90% of human breast tumors. These receptors interact with estrogen-receptor signaling, suggesting their involvement in a complex mechanism in cancer progression. Androgen receptors have become key players in breast cancer biology, offering new targets for therapeutic strategies. The presence of these receptors in both human and canine tumors raises important questions about their role in the development of these malignancies. While the exact mechanisms remain to be fully elucidated, research suggests that targeting androgen-receptor signaling could be a novel therapeutic approach for both humans and canines. Further studies are necessary to fully understand the implications of androgen-receptor expression and to develop more effective targeted therapies for these cancers.

Change in cytoarchitecture and reconnection of neurons in rats' brain under direct two months high frequency electromagnetic field (HFEMF) exposure has been found, supported with data and discussed. HFEMF used in the experiment had the following characteristics: 2.0 GHz frequency, 0.015 A/m intensity, electric field strength of 5.64 V/m, and SAR value was 2.5 W/kg. Rats were exposed for 6 hours a day for 6 days a week, during period of 60 days with experimental HFEMF. Six months after the treatment, histological and unbiased stereological analyses show that there is a reconnection of neurons in rats' brain, demonstrated by slight increase in their number and production of new dendrites. Effects of HFEMF on neuronal disconnection were detected via caspase, while the SNXS25 protein indicated their reconnection and regeneration. Immunohistochemical analysis of nervous tissue in this paper shows that HFEMF disrupt the work of proteins found on cell membranes and endocytic function of neurons and thus interrupts interneuron communication. The advantage of HFEMF over other methods of treating brain damage is in their controlled and very precise use, with specifically defined characteristics of HFEMF, without ionizing and mutagenic effect on neurons.

Background/Aim. The bladder outlet obstruction (BOO) index (BOOI) is used during urodynamic testing to diagnose BOO. The bladder contractility index (BCI) is a urodynamic parameter used inconsistently. The aim of this study was to examine the correlation between BOOI and BCI. Methods. A retrospective study was conducted from 2021 to 2023, including 176 male patients. Using the t-test, analysis of variance, and correlation analysis, BOOI and BCI were analyzed. Results. High BOOI values (40?80) and weaker bladder contractility (BCI < 100), as potential causes of lower urinary tract symptoms (LUTS), coexisted in 11.37% of cases. A high B CI value ( > 1 50) was associated with a significant number of patients (7.39%) with high BOOI values (> 40), acting a s a compensatory mechanism that masked the true causes of LUTS. Patient groups with BCI < 100 and > 150 showed an inverse correlation with BOOI, as expected. Values of BOOI 20?39 and BCI 101? 149 were considered a ?gray zone?. The correlation between PdetQmax and Qmax was not statistically significant (r = -0.2006), making BOO a factor that could influence this relationship. Additionally, the intraurethral catheter positioned during urodynamic testing significantly affected this correlation. As expected, a negative correlation was observed between Qmax and BOOI (r = -0.44841, p < 0.001), while BCI and Qmax had a positive linear correlation (R2 = 0.2255, p < 0.001). The correlation between the two observed indices, BOOI and BCI, showed a positive linear correlation, presenting a physiological mechanism for BOO compensation (R? = 0.3292, p < 0.001). Conclusion. In combination with BCI, BOOI is sufficient for establishing a definitive diagnosis in the analyzed patient groups. It is recommended that BOOI, BCI, and Qmax always be used in combination. Qmax, as a measure mostly valued on uroflow, may be insufficient for diagnosis in unequivocal clinical cases.

Effective antimicrobial stewardship (AMS) is crucial for combating the rise of antimicrobial resistance (AMR), particularly in veterinary medicine. Educational programs targeting veterinary students can play a significant role in shaping their knowledge and attitudes toward antimicrobial use and stewardship. This study aimed to evaluate the impact of educational programs on the knowledge and attitudes regarding AMS among veterinary students in Serbia. A structured educational program on AMS was implemented for veterinary students at the Faculty of Agriculture, University of Novi Sad. Pre- and post-symposium assessments were conducted to measure changes in students’ knowledge and attitudes. The study employed a mixed-methods approach, including surveys and focus groups, to gather quantitative and qualitative data. The study resulted in significant short-term improvements in students’ knowledge of AMS principles and their attitudes toward responsible antimicrobial use. Participants demonstrated a better understanding of the mechanisms of resistance and the importance of adhering to stewardship guidelines. Qualitative feedback indicated increased awareness of the consequences of inappropriate antimicrobial use and a stronger commitment to applying stewardship practices in their future careers. The educational programs effectively enhanced immediate veterinary students’ knowledge and attitudes regarding AMS. These findings underscore the importance of integrating targeted educational programs into veterinary curricula to promote responsible antimicrobial use and combat resistance in veterinary practice.

Yersiniosis, one of the leading foodborne infections in the European Union, is caused by Yersinia enterocolitica. In this study, the antibacterial and antibiofilm effects of cinnamon (Cinnamomum zeylanicum Nees), clove (Syzygium aromaticum L.), oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), and winter savory (Satureja montana L.) essential oils were investigated against Y. enterocolitica strains belonging to the bioserotype 4/O:3. Cinnamon essential oil showed the highest antibacterial activity, with an MIC value 0.09 µL/mL, followed by oregano and thyme essential oils, with MIC values from 0.09 to 0.18 µL/mL, and from 0.18 to 0.23 µL/mL, respectively. Thyme essential oil at 0.23 µL/g (MIC) and at 0.46 µL/g (2MIC) significantly (p < 0.05) reduced the number of Y. enterocolitica by 0.38 log CFU/g and 0.64 log CFU/g, respectively, in minced pork meat during storage at 4 °C for 4 days. The Y. enterocolitica strains formed biofilms at 15 °C and 37 °C in tryptic soy broth and Luria–Bertani broth, while no biofilms were obtained at 5 °C, and in meat broth nutrient media. Applying the minimum bactericidal concentrations of cinnamon, clove, oregano, rosemary, thyme, and winter savory essential oils on preformed biofilms led to significant reductions being observed in the range from 45.34% to 78.89%. A scanning electron microscopy assay showed the devastating impact of oregano and thyme essential oils on the morphology of Y. enterocolitica bacterial cells. In conclusion, the results of this study show that essential oils possess high anti-Yersinia and antibiofilm effects.

This paper presents the results of research into the impact of a digital system for monitoring dairy cows, which is based on the permanent monitoring of three physiological parameters (using a bolus with sensors), based on which changes can be used to diagnose the onset of estrus. The experiment was carried out with the aim of examining the success of this technology in improving the reproductive efficiency of the spawn. The test was carried out on one farm on a total of 50 calving cows of the Simmental breed, optimal body condition, divided into two groups. In this longitudinal study, animals were monitored before and after using the digital system. In the control group there were 25 cows inseminated based on the observed symptoms of estrus by the farm staff, while the experimental group consisted of 25 cows that were bolus applied and insemination was performed after detection of estrus diagnosed by the digital system. The results of this research show that the value of conception in cows from the experimental group was 61.54% (16/26). In cows from the control group, the conception rate was 48.00% (12/25). The results of this work indicate that the examined digital technology can significantly improve the conception value of inseminated cows and thus contribute to improving the reproductive efficiency of the herd.

Summary: Somatic cells (SCs) in milk, which include epithelial cells from the gland and blood cells, are present in milk during the normal course of milking. Increase in SCs is found in mastitis-affected dairy cows and can be a useful indicator for estimating mammary health and milk quality worldwide. The aim of this study was to determine whether there was a pattern of somatic cell count (SCC) in mastitis-affected cows on three different farms. The study was conducted on three dairy farms of high milk-producing cattle breeds in Vojvodina during 2021. Samples were taken from 15 cows from each farm, all of the cows being diagnosed with clinical and subclinical mastitis. The SCC in milk samples was determined by the microscopic reference method according to the standard (SRPS EN ISO 13366-1:2010) of the Institute for Standardization of Serbia. The value of SCC was considered as high if >200.000 cells/mL, as this is the threshold indicating secretion disorder. In order to examine the differences between the observed three farms, one-factor analysis of variance (ANOVA) was applied, while a post-hoc LSD test was used for determination of statistically significant differences between the SCC in cows on three different farms. The mean values of the SCC on Farms 1, 2 and 3 were 7,055,266.67, 2,619,893.33 and 552,000 cells/mL, respectively. Based on the results, a statistically significant difference (p<0.05) was established between Farms 1 and 2, as well as between Farms 1 and 3, while there was no statistically significant difference between Farms 2 and 3. Apart from mastitis, differences in the SCC on the farms could also be influenced by the cows’ productivity, parity, lactation stage and breed, as well as poor management practices. Besides mastitis control, better hygiene and proper nutrition can help in reducing SCs in milk. In conclusion, establishing SCs pattern can provide useful information that may contribute to reducing SCs and developing differential SCs standards to help obtain milk with low SCs and consequently better dairy products with a longer shelf life.