The use of antimicrobials in livestock production and their effect on the development of antimicrobial resistance (AMR) is a global health problem for humans, animals and the environment. The aim of this study was to determine antimicrobial residue levels in milk and feces samples during the withdrawal period in dairy cattle administrated with a single dose of the drug, as well as to characterize the antimicrobial resistance patterns of Escherichia coli cultured from feces samples. In the study, dairy cows from three different farms in North Macedonia were included. Raw milk and feces samples were collected before drug administration (0 day) and on the 1st, 2nd, 3rd, 7th and 21st day after drug administration. The antimicrobial residues of oxytetracycline, enrofloxacin, amoxicillin, trimethoprim and procaine-benzylpenicillin were determined using a validated liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) method involving stable isotopes. According to results obtained, the highest levels of analyzed antimicrobial residues were determined on the first day after drug administration, which then gradually decreased until their elimination (7th day). The highest AMR of E. coli (100%) was found in β-lactam antimicrobials. Less exposure to broad-spectrum antimicrobials could be an important factor for reduction of AMR on dairy farms.

The present study evaluated the effects of three β‑adrenergic agonists, salbutamol, clenbuterol, and terbutaline on growth performance and the kinetics of residue depletion in broiler chickens. A total of 100 Ross 308 chicks were randomly allocated to six treatment groups and one untreated control group. Each β‑agonist was administered via drinking water at two concentration levels (2.5 mg/L and 5 mg/L) starting on Day 19 of age. Body weight was monitored from Day 20 to Day 40 to assess growth performance. Additionally, residue depletion was investigated in breast muscle, liver, kidney, and feathers at predefined time points after treatment cessation. All β‑agonist‑treated groups exhibited significantly reduced body‑weight gain compared with the control group, regardless of compound or dose, indicating that none of the tested β‑agonists conferred growth‑promoting effects in broiler chickens under the conditions of this study. Residue analysis revealed rapid absorption and widespread tissue distribution of all three compounds, with the highest residue concentrations detected during the early post‑exposure period, particularly in kidney and liver tissues. Residue levels declined progressively during withdrawal and fell below the corresponding decision limits (CCα) in all edible tissues at later sampling points. Quantitative residue determination was performed using a validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) method compliant with Commission Decision 2002/657/EC. The findings confirm that salbutamol, clenbuterol, and terbutaline do not improve growth performance in broiler chickens and are efficiently eliminated from edible tissues when appropriate withdrawal periods are observed. These results support existing regulatory restrictions on the use of β‑agonists in poultry production and provide additional evidence relevant to food‑safety risk management.

Milk and dairy products are highly vulnerable to Economically Motivated Adulteration (EMA), particularly through the substitution of milk fat with cheaper non-milk fats. This paper presents a comprehensive review of analytical approaches used for detecting vegetable oils (e.g., palm, coconut, sunflower) and animal-origin fats such as pork lard and bovine tallow, as well as the fraudulent mixing of milk from different species. Methods for lipid extraction are examined, including traditional gravimetric procedures such as the Röse–Gottlieb method and high-efficiency alternatives such as Accelerated Solvent Extraction and supercritical fluid extraction. Analytical strategies for fraud detection are evaluated, demonstrating that while fatty acid profiling is widely applied, its sensitivity is limited by natural variability. Greater discriminatory power can often be achieved through triacylglycerol analysis combined with mathematical models such as the Precht formulae (which generate S-values), although performance varies depending on the adulterant matrix, adulteration level, reference population, and analytical protocol. Similarly, sterol profiling, particularly the detection of phytosterols like β-sitosterol, is a valuable marker for vegetable oil adulteration but does not provide an equivalent solution for detecting animal fat adulteration. The potential of rapid, non-destructive screening tools, including Fourier-transform infrared and Raman spectroscopy supported by chemometrics, is also assessed. A central analytical challenge in detecting such fraud lies in the complexity and variability of milk fat composition, which hinders any single analytical method from universally identifying all forms of non-milk fat adulteration; therefore, a tiered strategy combining rapid screening tools with high-resolution confirmatory methods is preferable. Future perspectives highlight the increasing importance of green analytical approaches, artificial intelligence, and portable detection systems for enhancing verification within the global dairy supply chain. However, the effectiveness of AI and chemometric methods depends heavily on the availability of representative training datasets and rigorous external validation to avoid overfitting and ensure reliable application across diverse samples.

β-Adrenergic agonists are banned as growth promoters in the European Union, and clenbuterol and salbutamol are routinely screened in poultry under national residue-control programs; characterizing their residue behavior in edible tissues therefore supports the detection of illicit use. This study examined the residue depletion and tissue distribution of salbutamol, clenbuterol, and terbutaline in 168 Ross 308 broiler chickens. Each compound was administered in drinking water at 2.5 or 5 mg/L for seven consecutive days, chosen to model a covert exposure route rather than an authorized feed protocol, followed by a withdrawal period. Concentrations in breast muscle, liver, and kidney were quantified using a validated LC–MS/MS method compliant with Commission Implementing Regulation (EU) 2021/808. Residue values are group mean concentrations of three birds per group per sampling point ( n = 3); because the individual per-bird results were not retained, no measures of dispersion are reported for the residue data. Quantifiable residues were detected in all three tissues at the first post-treatment sampling point, with the highest concentrations in kidney and liver and the lowest in breast muscle. Residues declined over the withdrawal period; terbutaline depleted most rapidly and clenbuterol persisted longest, and apparent depletion half-lives derived by log-linear regression were 1.1–1.5 days in liver and 0.7–1.2 days in kidney. By Day 46, all residues were below their respective matrix-specific decision limits (CCα), and no growth-promoting effect was observed for any compound at either concentration. Under this short drinking-water exposure, the three β-agonists showed distinct, tissue-dependent residue-depletion profiles but no measurable growth-promoting response in broilers. The comparative dataset, referenced to validated CCα values, supports residue surveillance and food-safety risk assessment of β-agonist residues in poultry.