Biochemical and molecular genetic indicators of antioxidant protection and immunity in male chicks (Gallus gallus domesticus) of different genotypes

A comparative study of the relationship between the antioxidant protection (AOP) and immunity in poultry of various genotypes is relevant for clinical and physiological assessment of health status and the search for combinations of genotypes to obtain new crosses. In this work, for the first time, differences in biochemical and molecular genetic indicators of antioxidant protection and immunity were established for the Russian White, Ross 308 cross, and Russian White ½ Cornish cockerels. Correlations were revealed between the expression of some genes for AOP and immunity enzymes in caecum and liver tissues, and the average daily weight gain. The aim of the work was to assess the factors of immunity and antioxidant status, nonspecific immunity indicators, and gene expression levels for enzymes involved in antioxidant protection and immune response in male chickens ( Gallus gallus domesticus ) of different genotypes. The studies were carried out in 2022 at physiological yard of the Ernst Federal Research Center for Animal Husbandry. Blood samples were taken from Russian White cockerels (RW, n = 28), Ross 308 cross broilers (n = 9) and Russian White × Cornish cockerels (CORN × RW, n = 128) at slaughter at the age of 9 weeks. The TBA test with thiobarbituric acid to measure the TBA-active products (TBA-AP) was performed with Agat-Med kits (Russia). The activity of ceruloplasmin (CP) was determined by the Revin method, the amount of total water-soluble antioxidants (TAWSA) amperometrially (a TsvetYauza-01-AA with an amperometric detector, Khimavtomatika, Russia), the ratio of TBA-AP to the CP was calculated. TAWSA was evaluated as equivalents to gallic acid using calibration solutions with a mass concentration of 0.2, 0.5, 1.0 and 4.0 mg/dm3 prepared from 100 mg/dm3 gallic acid. A solution of orthophosphoric acid (0.0022 mol/dm3) was used as an eluent. Other indicators of antioxidant status were determined with commercial kits (Elabscience Elabscience Biotechnology, Inc., China). Reduced glutathione (E-BC-K096-M), superoxide dismutase (SOD) (E-BC-K020-M), catalase (E-BC-K031-M) and total antioxidant status (TAS) (E-BC-K219-M) were measured by ELISA test (an Immunochem-2100 microplate photometer, High Technology Inc., USA). Nonspecific immunity (i.e., bactericidal activity BA and lysozyme activity LA) of RW ( n = 12), CORN ½ RW ( n = 68) and Ross 308 ( n = 9) male chicks were determined (a microbiological analyzer Multiskan FC, ThermoFisher Scientific Inc., Finland). Analysis of relative gene expression was performed using real-time PCR. Tissue samples of the caecum and liver were taken from RW ( n = 10), Ross 308 ( n = 9), and CORN ½ RW ( n = 11) cockerels, 30 samples of each tissue. The relative expression of the genes responsible for antioxidant protection (catalase CAT , glutathione peroxidase GSH-Gpx , heme oxygenase 1 HO-1 , superoxide dismutase SOD , related transcription factor 2, NF-E2 Nrf2 ) and involved in the immune response (avian beta defensin 9 AvBD9 , interleukin 6 IL6 , interleukin 8 IL8 ) was assessed. Total antioxidant status (TAS) of broilers was lower than that of analogues, which was confirmed by the maximum content of TBA-AP, 4.27 vs. 3.04 µmol/l for RW (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }