Cattle breeds or crossbreds with high productivity traits have been developed to meet a growing demand for food. When intensive farming practices are followed, animals face several challenges which can result in poor performance, compromised welfare and the reduced quality of their products. Our study aims to highlight the resting values of the physiological oxidative stress that three cattle breeds exhibit, and their potential relationship with meat quality. For this purpose, we determined the levels of five common redox biomarkers (glutathione (GSH), catalase (CAT), total antioxidant capacity (TAC), thiobarbituric reactive substances (TBARS) and protein carbonyls (CARBS)) in the tissues of three commonly used beef cattle breeds (Charolais (CHA), Limousin (LIM) and Simmental (SIM)) and their association with specific meat quality traits that depend on color, pH and texture. The results revealed that LIM cattle breed animals have elevated intrinsic antioxidant defense systems in comparison to CHA and SIM cattle breed animals. In addition, the meat quality parameters were associated with the redox biomarkers. We propose that the determination of specific antioxidant parameters in the blood might be used as potential biomarkers to predict meat quality. This would allow farmers to nutritionally intervene to improve the quality of their products.

Sheep farming in Greece is focused on milk production. Meat is considered a by-product and consists mainly light carcasses of undefined quality. The main challenge of the sector is to ensure sustainability, and hence efforts are towards efficient use of available resources, including undervalued carcasses of local fat-tailed sheep. The objective here was twofold: (i) to assess the carcass quality of fat-tailed sheep slaughtered at different live weights and (ii) to compare them with carcasses from thin-tailed sheep. In total, 146 fat-tailed and 97 thin-tailed dairy sheep were used. They belonged to five live-weight categories (LWC), representing 25%, 35%, 50%, 70% and 100% of mature body weight. Carcass length/weight/yield/pH and wither height were recorded. Muscle fiber minimum Feret’s diameter and meat color/tenderness/moisture/lipid and protein content were determined. Sex and LWC differences in fat-tailed sheep were assessed. Parametric and non-parametric tests were used to compare with thin-tailed sheep, considering the effects of LWC, sex and their interactions with sheep population (fat-tailed/thin-tailed). Most traits were significantly different (p < 0.05) between groups of fat-tailed sheep. Carcass yield of fat-tailed sheep was significantly higher compared to thin-tailed (p < 0.01). Interactions of sheep population with LWC or sex affected wither height, carcass pH, meat color and tenderness (p < 0.05). Fat-tailed sheep meat quality is equal or higher compared to thin-tailed. Finishing weights corresponding to 50 and 70% LWC may improve capitalization of fat-tailed carcasses.

The current study evaluated the effects of milk thistle extract supplementation in laying hens’ fed diets lacking choline chloride addition. A total of 60 Isa-brown laying hens were randomly allocated into T1: control diet, 0% extract supplementation; T2: control diet with 1% extract; T3: control diet with 2.5% extract; and T4: control diet with 4% extract. Egg quality parameters, yolk lipid oxidation, malondialdehyde (MDA) content, and fatty acid profile were assessed. Livers were examined grossly and histologically to evaluate hepatocellular lesions such as vacuolization (lipidosis), reticular stromal architecture, the amount of collagenous connective tissue, and vascular wall changes. Groups T3 and T4 showed darker yolks compared to both control group and T2 (p = 0.001) and redness of the egg yolk (p < 0.001). The MDA was lowest in T2 group which had improved gross appearance with lower degrees of hepatic vacuolization than other groups. Liver discoloration was milder in T3 (43.8%) compared to the T1 and T4 groups (18.8% and 12.5%, respectively, p = 0.013). Reticulin loss was correlated with the degree of hepatic vacuolization (r = 0.751, p < 0.001). Supplementation with MT extract in diets lacking choline chloride may influence certain egg quality indices and liver gross macroscopic lesions in laying hens.

The objective of this study was to assess the resting values of the physiological oxidative stress exhibited by lambs and kids reared in Greece, and the potential correlations between redox biomarker levels in blood and other tissues (liver, diaphragm, quadriceps, psoas major muscle). For this purpose, lambs and kids at different developmental stages (d.s.) were used. The latter corresponded to four live weight categories (LWC), each representing 25%, 35%, 70% and 100% of mature body weight. In each of the above tissues, the levels of five common redox biomarkers were determined: glutathione (GSH), catalase (CAT), total antioxidant capacity (TAC), thiobarbituric reactive substances (TBARS), and protein carbonyls (CARBS). The results revealed that lambs and kids belonging to the 35% LWC had weaker endogenous antioxidant pools, while animals in the 70% and 100% LWC had elevated intrinsic antioxidant defense systems. Blood redox biomarkers were associated with the respective ones measured in the diaphragm, liver, quadriceps, and psoas major of both species. Importantly, TBARS levels in blood of animals in the 25% and 100% LWC are correlated with the TBARS levels in all other tissues tested. Blood antioxidant parameters might be used as potential biomarkers to predict the antioxidant status of tissues that affect meat quality. The latter would facilitate quality assessment prior to slaughter, allowing for timely nutritional interventions that can improve meat products.