Evaluation of the Quality of Guinea Fowl (Numida meleagris) Eggs from Free-Range Farming Depending on the Storage Period and Age of Laying Hens.

The aim of the study was to determine the changes occurring in the eggs of helmeted guinea fowl (Numida meleagris) from free-range farming in relation to the laying season and storage time. The experimental material consisted of 360 guinea fowl eggs, collected in the first, second and third laying seasons and stored for 7, 14 and 21 days. After each period, physical and physicochemical characteristics of the eggs were determined, as well as the basic chemical composition and mineral content of the albumen and yolk and the yolk fatty acid profile. The age of the guinea fowls affected certain physical parameters of the eggs. The egg weight, shape index and shell thickness increased with the age of the laying hens; however, a decrease in the proportion of shell in the egg was demonstrated. Storage time had a significant effect on egg weight, weight loss during storage and air cell height. Significant differences were found in the chemical composition of guinea fowl eggs depending on the age of the laying hens. Eggs obtained from older laying hens were characterized by higher yolk fat content and lower ash content, while the albumen contained higher water content and lower ash content. During the three-year laying period, changes were observed in the mineral composition of the eggs. The fatty acid profile underwent significant changes; however, no important differences were observed in the total content of SFA, MUFA, PUFA and n-6 fatty acids. Conversely, significant differences were found for n-3 acids and the n-6/n-3 ratio. Eggs in the first and second laying seasons exhibited the most favorable composition. The slow dynamics of changes occurring in successive laying seasons and egg storage time indicated that the raw material studied was safe and could be used by consumers.

Interaction between Enrofloxacin and Three Essential Oils (Cinnamon Bark, Clove Bud and Lavender Flower)-A Study on Multidrug-Resistant Escherichia coli Strains Isolated from 1-Day-Old Broiler Chickens.

Avian pathogenic Escherichia coli (APEC) causes a variety of infections outside the intestine. The treatment of these infections is becoming increasingly difficult due to the emergence of multi-drug resistant (MDR) strains, which can also be a direct or indirect threat to humans as consumers of poultry products. Therefore, alternative antimicrobial agents are being sought, which could be essential oils, either administered individually or in interaction with antibiotics. Sixteen field isolates of E. coli (originating from 1-day-old broilers) and the ATCC 25922 reference strain were tested. Commercial cinnamon bark, clove bud, lavender flower essential oils (EOs) and enrofloxacin were selected to assess the sensitivity of the selected E. coli strains to antimicrobial agents. The checkerboard method was used to estimate the individual minimum inhibitory concentration (MIC) for each antimicrobial agent as well as to determine the interactions between the selected essential oil and enrofloxacin. In the case of enrofloxacin, ten isolates were resistant at MIC ≥ 2 µg/mL, three were classified as intermediate (0.5-1 µg/mL) and three as sensitive at ≤0.25 µg/mL. Regardless of the sensitivity to enrofloxacin, the MIC for cinnamon EO was 0.25% v/v and for clove EO was 0.125% v/v. All MDR strains had MIC values for lavender EO of 1% v/v, while drug-sensitive isolates had MIC of 0.5% v/v. Synergism between enrofloxacin and EO was noted more frequently in lavender EO (82.35%), followed by cinnamon EO (64.7%), than in clove EO (47.1%). The remaining cases exhibited additive effects. Owing to synergy, the isolates became susceptible to enrofloxacin at an MIC of ≤8 µg/mL. A time-kill study supports these observations. Cinnamon and clove EOs required for up to 1 h and lavender EO for up to 4 h to completely kill a multidrug-resistant strain as well as the ATCC 25922 reference strain of E. coli. Through synergistic or additive effects, blends with a lower than MIC concentration of enrofloxacin mixed with a lower EO content required 6 ± 2 h to achieve a similar effect.

Evaluation of the Antibacterial Activity of Gentamicin in Combination with Essential Oils Isolated from Different Cultivars and Morphological Parts of Lavender (Lavandula angustifolia Mill.) against Selected Bacterial Strains.

The aim of the study was to investigate the antibacterial effects of essential oils isolated from different cultivars and morphological parts of lavender (Lavandula angustifolia Mill.) in combination with the aminoglycoside antibiotic gentamicin. This in vitro study analyzed the effectiveness of the combinations of gentamicin and lavender essential oils against the following strains: Staphylococcus aureus ATCC 25923, Staphylococcus aureus MRSA and Pseudomonas aeruginosa ATCC 9027. The effect of the combination of lavender oils with gentamicin was tested using the checkerboard method. A synergistic effect against S. aureus strain ATCC 25923 was found when gentamicin was combined with lavender essential oils isolated from flowers and leafy stalks (flowers: 'Blue River' FICI-0.192; 'Ellagance Purple' FICI-0.288; leafy stalks: 'Blue River' FICI-0.192; 'Ellagance Purple' FICI-0.320). A synergistic effect was also observed for the combination of gentamicin with lavender essential oils from flowers against the resistant strain of S. aureus (MRSA) ('Blue River' FICI-0,191; 'Ellagance Purple' FICI-0.263), as well as for the essential oils from leafy stalks ('Blue River' FICI-0.076; 'Ellagance Purple' FICI-0.089). No interaction was observed for the combination of studied essential oils with gentamicin against P. aeruginosa strain ATCC 9027 (FICI = 1.083-1.300).

Lavandula angustifolia Essential Oils as Effective Enhancers of Fluconazole Antifungal Activity against Candida albicans.

The increasing prevalence of Candida albicans resistance to commercial antifungal agents in recent decades has prompted modern medicine and veterinary medicine to search for combined treatment options. The aim of the study was to determine the activity of essential oils from different cultivars and morphological parts of the medicinal lavender (Lavandula angustifolia) in combination with fluconazole against Candida albicans ATCC 10231 strain. The effect of the combination of lavender essential oil with fluconazole was tested using the checkerboard method, and the obtained results were interpreted on the basis of fractional inhibitory concentration indices (FICIs). A synergistic interaction was found for all combinations of fluconazole with essential oils isolated both from flowers and leafy stalks of two tested lavender cultivars: 'Blue River' and 'Ellagance Purple'. The observed enhancement effect of fluconazole antifungal activity was significantly stronger in the case of essential oils obtained from flowers and leafy stalks of 'Blue River' cultivar. Analogous studies were performed for linalool, one of the main components of lavender essential oils, and a similar synergistic interaction with fluconazole was found.

The effect of lavender (Lavandula angustifolia) essential oil as a drinking water supplement on the production performance, blood biochemical parameters, and ileal microflora in broiler chickens.

The aim of this study was to evaluate growth performance, selected biochemical blood parameters, and the microbiota of ileal digesta in broiler chickens provided with drinking water containing an addition of natural lavender essential oil (LEO). The experiment was carried out on a commercial farm using n = 300 unsexed Ross-308 broiler chickens. One-day-old chicks were randomly assigned to three groups of 100 chickens each (five replications, 20 individuals each). The control group broilers were provided with drinking water without the addition of LEO. Groups LEO1-42 and LEO22-42 had access to water containing 0.4 ml/L LEO (for 6 h/day) from days 1 to 42 (LEO1-42) and 22 to 42 (LEO22-42). Body weight, feed intake, water intake, and mortality were recorded throughout the experiment. The analyses reveal that the addition of LEO has a positive effect on body weight in the second period of rearing (d 22-24). Treatment broilers (LEO1-42 and LEO22-42) weighed on average 6.35% more compared to the control (P < 0.01). LEO addition positively affected weight gains and feed conversion ratio (P < 0.01) in the second period of rearing (d 22-24). No differences were found between the groups feed intake, water intake, survival rate, and blood biochemical parameters (P > 0.05). The addition of LEO to drinking water had a positive impact on the gut microflora of the ileum: the numbers of pathogenic microorganisms decreased (Escherichia coli and coliform) while the number of probiotic bacteria increased (P < 0.01).