The aim of this study was to determine the effect of in ovo co-supplementation of chicken embryos with a multi-strain probiotic containing effective microorganisms and zinc glycine chelate on total antioxidant capacity; concentrations of sulfhydryl groups, bityrosine bridges, formylkynurenines, hydroperoxides, proteins, corticosterone, pro- and anti-inflammatory cytokines and heat shock proteins; and the activity of catalase and superoxide dismutase in the serum, yolk sac and tissues of broiler chickens at 12 h and at 7 days after hatching. The results indicate high SOD activity in the small and large intestines of chicks at 12 h post-hatch in the groups receiving the multi-strain probiotic and in the small intestine and yolk sac of birds receiving the multi-strain probiotic and Zn-Gly chelate. High concentrations of TNF-α and IFN-γ in the yolk sac and serum after in ovo administration of Zn-Gly chelate were observed 12 h after hatching. The use of a probiotic and a probiotic with Zn-Gly chelate increased the total antioxidant capacity in the tissues of chickens. It can be concluded that in ovo administration of a multi-strain probiotic and Zn-Gly chelate can maintain the oxidant/antioxidant balance in chickens and increase the defense capacity against oxidative stress.

Increased metabolism that occurs during pregnancy can result in oxidative stress which is harmful to cells and, consequently, for the proper functioning of the whole organism. Plasma and recently also saliva are important resources for evaluating physiological and pathological conditions in animals. The study aimed to investigate the influence of the metabolic state on the effectiveness of the antioxidant profile of plasma and saliva during the pregnancy of cows. Seventy-six healthy pregnant and twelve non-pregnant control cows were included in the study. Blood and saliva samples were collected each month of the pregnancy course. Examined body fluids were used to evaluate both the total antioxidant capacity (TAC) and the oxidative parameters related to protein and lipid peroxidative processes. TAC, the content of hydroperoxides, and SH groups were determined spectrophotometrically while formylokinurenine and bityrosine contents were measured spectrofluorimetrically. The results showed dynamic changes depending on the period of pregnancy course. The highest antioxidant activity in plasma was mostly noted in early pregnancy and advanced pregnant cows. All tested parameters except SH groups expressed higher values in saliva compared to plasma. Obtained results reveal that the increase in oxidative intensity induced appropriate answers of cells reflected in the increase in antioxidative activity of the organism. Moreover, some examined parameters can indicate the intensity of oxidative stress and therefore could be used in a panel of markers of the physiological course of pregnancy. However, with regards to antioxidant/oxidative parameters, saliva reflects the content of plasma only in part, due to the local metabolism of the salivary gland. Further studies are necessary to establish physiological ranges of antioxidative/oxidative profiles in cows and to define the usefulness of saliva as biological material in oxidative stress diagnostics.