Background: The use of zinc oxide in the form of nanoparticles (ZnO-NPs) is of great benefit due to its potent effectiveness and higher bioavailability compared to zinc oxide. This study aimed to investigate the impact of dietary inclusion of different doses of ZnO-NPs on selected serum biomarkers, lipid peroxidation and tissue gene expression of antioxidant enzymes and cytokines in Japanese quail. Eighty Japanese quails (Coturnix japonica) (45 days old) were randomly divided into four groups (20 birds for each) with 4 replicates (5 birds each). Birds in the first group were fed a basal diet alone and served as a control (C). Birds in groups 2–4 were fed the basal diet supplemented with ZnO-NPs at doses of 15 mg/kg, 30 mg/kg and 60 mg/kg for a period of 60 days. At the end of the experiment, all birds were sacrificed to collect blood in a plain vacutainer, whereas liver and brain tissues were stored frozen at -80 °C. The obtained sera were used for the analysis of selected biochemical parameters, whereas tissue homogenates were used for the estimation of zinc, oxidative stress biomarkers and gene expression of selected antioxidant enzymes and cytokines. Results: ZnO-NPs (30 and 60 mg/kg) induced a significant decrease in serum triacylglycerol (TAG) compared to the control. ZnO-NPs did not affect the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein, albumin, globulin and tissue zinc concentrations but reduced the malondialdehyde (MDA) levels compared to the control. The liver retained a higher zinc concentration than that of brain tissue. In a dose-dependent manner, ZnO-NPs upregulated the mRNA levels of antioxidant enzymes (superoxide dismutase: SOD1; catalase: CAT; glutathione peroxidase-1: GPX 1) and pro-inflammatory cytokines (interferon α: IFN-α; interleukin 6: IL-6) in liver and brain tissues. Conclusion: The current study suggests the inclusion of ZnO-NPs, particularly 60 mg/kg, in the diet of Japanese quails to improve antioxidant and immune status.

This study aimed to evaluate the effect of four combinations of dietary linseed oil and lysine mixtures on performance, fatty and amino acid profiles, oxidative stress biomarkers, cell energy and meat quality parameters of broiler chickens. One hundred and sixty broiler chicks were allocated into four groups. Birds of groups 1–4 were fed diets containing optimum lysine and 2% of linseed oil, optimum lysine and 4% of linseed oil, high lysine and 2% of linseed oil, and high lysine and 4% of linseed oil, respectively, for a period of 35 days. High linseed oil or lysine levels did not affect the performance of the tested birds, but the high level of dietary linseed oil decreased the concentrations of muscles’ saturated fatty acids (SFA). The highest values of ω-3 polyunsaturated fatty (ω-3 PUFA) and arachidonic acids with lowest levels of monounsaturated fatty (MUFA) were detected in the muscles of birds fed diets containing high linseed oils and/or lysine levels. High linseed oil or lysine levels provided the best essential amino acid profile and improved antioxidant components as well as cell energy, and tenderness and redness of the meat. Conclusively, high dietary lysine and linseed oil combinations improved the nutritional value, antioxidant status and cell energy of broiler chickens’ meat.

Three different diets were formulated with three levels of metabolizable energy (ME) (optimum; 2900, restricted; 2800 and low; 2700 kcal ME/kg diet) without or with (0 and 0.15%) betaine supplementation in 2 × 3 factorial design to evaluate the effect of six experimental diets on performance, proteins and lipids profiles, bioenergetics, peroxidation and meat quality of Japanese quail. Therefore, 360 quails allocated into six groups in a 23-day experiment. Dietary betaine and ME levels did not affect the performance, meat energy indices (ATP and AMP) and malondialdehyde (MDA) levels of Japanese quail meat. Dietary betaine and/or ME levels induced significant changes in serum triacylglycerol (TAG), total cholesterols (TC), low-density lipoprotein cholesterol (LDL-c), very low-density lipoprotein cholesterol (VLDL-c), meat total lipids and cholesterol of Japanese quail. Optimum and restricted ME levels reduced total volatile basic nitrogen (TVBN) whereas dietary betaine increased ecosapentaenoic (EPA), docosahexaenoic acids (DHA) and glutamine concentrations in breast meat of Japanese quail. Dietary betaine and low energy diet improved cooking loss, thawing loss (ThL) and water holding capacity (WHC) in breast meat of Japanese quail. Conclusively, dietary betaine improved meat quality of Japanese quail fed diets containing either restricted or low ME by enrichments the meat with omega-3 fatty acids and reduction of lipids levels.

Nile tilapia, a widely cultivated freshwater fish, faces significant stressors, such as hypoxia and cold temperatures, which can negatively impact its quality and growth. The current study explored the impact of Chlorella vulgaris (CV) powder and its nanoparticles (CVNPs) on the growth performance, antioxidant capacity, liver protection, and meat quality of Nile tilapia to alleviate hypoxia and cold stress. A total of 450 healthy 28-day-old Nile tilapia fingerlings (average weight 5.32 ± 1.1 g, length 3.1 ± 0.5 cm) were divided into five groups: T1 (2.5 g/kg CV), T2 (5 g/kg CV), T3 (2.5 g/kg CVNP), T4 (5 g/kg CVNP), and the control group received a basal diet without additives, each with three subgroups in tri-replicate (10 fish/replicate). After six weeks of feeding, growth metrics and meat quality parameters were assessed, and each group was subjected to hypoxia, cold stress, or optimal conditions. The results revealed that T4 exhibited the highest weight gain (WG) and lowest feed conversion ratio (FCR), whereas T1 showed the highest specific growth rate (SGR) and length gain. Hypoxia and cold stress significantly (p < 0.05) increased cortisol, oxidative markers (MDA, NO, and GSSG), and liver enzymes (ALT and AST) while reducing (p < 0.05) antioxidant markers (SOD and GSH) and total cholesterol (TC). ATP levels significantly (p < 0.05) decreased in hypoxic fish, indicating muscle energy depletion. T1 significantly (p < 0.05) lowered cortisol levels, whereas T2 and T3 significantly (p < 0.05) increased superoxide dismutase (SOD) levels. T2 also significantly (p < 0.05) increased the TC level. ALT levels significantly (p < 0.05) decreased at T1, T2, and T4, with AST levels reduced at T4 only. CV and CVNP supplementation significantly (p < 0.05) reduced the muscle MDA levels under optimal and stressful conditions, notably at T1 and T4. Additionally, meat lightness, yellowness, and chroma significantly (p < 0.05) increased in stressed tilapia, whereas meat redness was improved under optimal conditions. Fatty acid profiles varied with CV and CVNP levels across different conditions. In conclusion, CV, particularly in the nanoparticle form, enhanced the growth, antioxidant activity, and meat quality of tilapia under physical stress.

SUMMARY. The current study investigated the effect of heat processing or carbohydrase enzyme addition on egg production, egg quality, egg fatty acid compositio