As the demand for poultry meat and eggs is increasing in the world, and the use of antibiotics is forbidden in Europe (since 2006), with countries such as the Philippines, Thailand, Bangladesh and China having imposed restriction or prohibitions, researchers and producers have sought for effective non-antibiotic alternatives. Probiotics, prebiotics, synbiotics and phytobiotics are frequently used as alternatives in the field of poultry production. Phytobiotics, plant-derived substances, also referred to as botanicals or phytogenics, are used as animal diets supplements due to their wide range of bioactive compounds (menthol, curcumin, eugenol, allicin and others) and many advantages. They are classified as herbs, spices, plant extracts and essential oils. Some of the benefits offered by the dietary phytobiotics are antimicrobial, antioxidant, digestion stimulant, anti-inflammatory, immunomodulatory, carminative, antiseptic and appetite stimulant, the modulation of gut microbiota and improvement in the intestinal histology. Some representatives of phytobiotics are turmeric, oregano, sage, thyme, black pepper, ginger, garlic, echinacea, rosemary and others. Despite the significant potential of phytobiotics, their widespread adaptation is currently inhibited by challenges regarding cost-effectiveness (high price for raw materials), scarce regulatory frameworks, and inconsistent biological efficacy. The lack of standardization reflects a dual challenge, enclosing both the inherent chemical variability of raw botanical materials and the technical inconsistencies present throughout the industrial manufacturing, and extraction processes as producers use different machinery for extracting and producing the animal feed. To address these systemic impediments, a joint effort across the entire value chain—from primary producers to regulatory authorities—is essential for the development of unified testing protocols and standardization dosage guidelines that ensure the pharmacological safety and reliability of phytobiotic products.

This study examined the effects of dietary aniseed, thyme, and basil essential oils (EOs) on growth, health, and tissue integrity of common carp (Cyprinus carpio) reared in a recirculating aquaculture system (RAS). Juvenile carp (102 ± 2.8 g) were fed for 12 weeks four isonitrogenous diets: a control and three diets supplemented with 0.2% aniseed (V1), thyme (V2), or basil (V3) oils. Growth performance was not significantly affected (p > 0.05). Flesh biochemical composition improved, with higher protein in V1 (17.85 ± 0.22%) and lower fat in V3 (1.78 ± 0.21%) compared to the control. Hematological parameters and antioxidant enzymes (SOD, CAT, GPx) indicated enhanced immune and oxidative status, while MDA (malondialdehyde) levels decreased. SOD activity increased in treated groups, reaching 4.329 U mg⁻¹ protein in muscle and 4.908 U mg⁻¹ protein in liver in V2, compared to 2.775–3.677 U mg⁻¹ protein (muscle) and 3.508–4.349 U mg⁻¹ protein (liver) in controls. CAT activity was highest in the same group 57.045 U mg⁻¹ protein versus 31.403 U mg⁻¹ protein in controls. Microbiological assessment revealed reduced total aerobic bacteria and Enterobacteriaceae counts in EO-fed fish. Histological analysis showed healthier hepatic and intestinal structures, reduced vacuolation, intact epithelium, and abundant goblet cells in EO-treated groups.

The aim of this study was to evaluate the effects of incorporating Black Soldier Fly Meal (BSFLM) into the diet of two-year-old carp on growth and health status. Four concentrations of BSFLM were tested, T1-0% (control), T2-10%, T3-20%, and T4-30%, in common carp with an initial body weight of 112.06 ± 3.86 g over a 12-week feeding period. The results showed that final weight and weight gain were 17.3% (349.15 g) and 23% (233.6 g) higher in the T4 group compared to the control (298.63 g and 189.79 g, respectively). Flesh composition showed no significant changes. Hematological variations were insignificant. Oxidative stress assessment revealed increased activities of antioxidant enzymes (SOD, CAT, and GPx) alongside reduced lipid peroxidation. The counts of anaerobic microorganisms and Enterobacteriaceae in intestine increased linearly in BSFLM groups. Histological examination showed normal intestinal and hepatopancreatic morphology in the 10% and 20% BSFLM groups (T2 and T3). In contrast, the 30% inclusion level (T4) was associated with hepatocellular vacuolization and alterations in villus architecture. In two-year-old carp, dietary BSFLM induced dose-dependent responses, whereby higher inclusion levels supported weight gain but adversely affected the morphological integrity of the intestine and hepatopancreas.

The absence of standardized reference values for wild rodent species underscores the need for comprehensive hematological and biochemical profiles. This study established robust reference intervals (RIs) for Myocastor coypus raised in captivity, analyzing 30 nutrias (10 males, 10 females, and 10 juveniles) at a private farm in northeastern Romania. Leukocyte (WBC) counts averaged 11.85 (10³/µL) in males, 10.51 (10³/µL) in females, and 11.63 (10³/µL) in juveniles, indicating a consistent immune response. Hemoglobin was 11.81 g/dL in males, 11.97 g/dL in females, and 15.42 g/dL in juveniles, with hematocrit levels around 45%. Juveniles displayed higher MCH (38.59 pg) and MCHC (38.58 g/dL), reflecting growth-related adaptations. Platelet counts were lower in adults. Biochemical findings showed lower cholesterol (14.89 mg/dL) and higher glucose (236.26 mg/dL) in juveniles, indicating intense energy metabolism. Total proteins were significantly elevated in juveniles (33.17 g/dL). Creatinine and uric acid levels were higher in adults, although calcium exceeded reference ranges in males (12.04 mg/dL). Hepatic enzyme ALT was higher in males. These findings establish baseline health parameters for captive nutrias, aiding in monitoring and improving rearing practices.

The aim of this study was to evaluate the effects of moderate and chronic stress on the biochemical and metabolic responses of rabbits (Oryctolagus cuniculus). The experiment involved three groups of animals: the control group (L1), the group exposed to moderate stress (L2), and the group exposed to chronic stress (L3), each consisting of 20 individuals. The analyzed parameters included glucose, cholesterol, total proteins, albumin, and plasma cortisol. The rabbits were subjected to different stress induction protocols for two and four weeks, respectively, and blood samples were collected for biochemical analysis. The results revealed that stress exposure led to significant increases in plasma cortisol and glucose levels, particularly in the chronic stress group. Alterations in albumin and cholesterol levels were also observed, suggesting a disruption of metabolic homeostasis. The differences among groups were statistically confirmed (p 0.05). This study highlights the profound impact of chronic stress on the metabolic responses of rabbits, emphasizing the necessity of managing stressors in companion animals and experimental settings. These findings contribute to a better understanding of the physiological mechanisms involved in stress responses and offer insights for improving animal welfare.

Understanding physiological variability in wild ungulates is essential for ecological monitoring and sustainable wildlife management. This study aimed to examine whether sex and season (autumn vs. early winter) significantly influence hematological and biochemical parameters in free-ranging red deer (Cervus elaphus) from the Eastern Carpathians, Romania. A total of 40 legally harvested adult individuals (20 males, 20 females) were included, and blood samples were collected post-mortem under standardized conditions to minimize pre-analytical variability. Hematological parameters (WBC, RBC, HGB, HCT, PLTs) and serum biochemical markers (glucose, urea, total cholesterol, triglycerides, total protein) were analyzed using automated veterinary analyzers. Statistically significant sex-related differences were found in hematocrit during autumn and hemoglobin concentration during winter, with higher values in males. Seasonal variation within sex groups was not significant but indicated a physiological trend toward hemoconcentration in winter. Biochemical values remained within reference ranges and showed no significant differences across groups. Pearson’s correlation analysis revealed a strong association between hematocrit and urea, and moderate correlations were observed between WBC and glucose, suggesting links between oxygen transport, protein metabolism, and energy balance. Environmental factors such as reduced food availability and temperature shifts during winter likely contribute to these physiological adjustments. These results provide baseline data for the physiological assessment of red deer populations and support the development of ecological health indicators in wildlife monitoring programs. Future studies incorporating hormonal and immunological biomarkers across multiple seasons are encouraged to further understand adaptive responses in cervids.