Changes in the redox parameters in blood plasma at Days 3, 8, 21, 32, and 42.

(A) MDA concentration. (B) Vitamin E concentration. (C) Vitamin C concentration. (D) GSH concentration. (E) GPx activity. (F) GR activity. (G) SOD inhibition rate. (H) DTNB-thiol concentration. (I) Albumin concentration. Significant differences were determined by comparing the data from each time point with the data from the first time point. Data are expressed as the means ±8 SEMs; *P<0.05, ** p<0.005, *** p<0.001.</p

The concentration of AST in plasma at Days 3, 8, 21, 32, and 42.

Significant differences were detected when comparing the data from the first time point with the data from subsequent time points. Data are expressed as the means ± SEMs; *P<0.05, ** p<0.005, *** p<0.001.</p

Transsulfuration pathway and antioxidant system.

Tetrahydrofolate (THF); 5,10-methylene-tetrahydrofolate (5,10-Methylene-THF); methionine synthase (MS); methionine (Met);betaine homocysteine methyltransferase (BHMT); dimethylglycine (DMG); S-adenosylmethionine (SAM); methionine adenosyltransferase (MAT); S—adenosylmethionine (AdoMet); glycine N-methyltransferase (GNMT); S-adenosylhomocysteine (AdoHcy); S-adenosylhomocysteine hydrolase (SAHH); homocysteine (Hcy); cystathionine β-synthase (CBS); cystathionine γ-lyase (CTH); α-ketobutyrate (αKB); aspartate aminotransferase (AAT); sulfinoalanine decarboxylase (SAD); Hypotaurine dehydrogenase (HPD); cystine reductase (Cyss R); Glutathione-cystine transhydrogenase (GSH-Cyss TH); γ-glutamylcysteine synthase (GCS); glutathione synthase (GS); and aspartateaminotransferase(AST).</p

The concentrations of inflammatory markers in the plasma at Days 3, 8, 21, 32, and 42.

(A)IL-2 concentration. (B) IL-4concentration. (C) IL-6concentration. (D) TNF-α concentration. Significant differences were determined by comparing the data from each time point with the data from the first time point. Data are expressed as the means ± SEMs; *P<0.05, ** p<0.005, *** p<0.001.</p

The concentration of total thiols in the blood plasma on Days 3, 8, 21, 32, and 42.

(A) Cys concentration. (B) GSH concentration. (C) NAC concentration. (D) Hcy concentration. (E) Cys-Gly concentration. (F) γ-GC concentration. (G) Significant differences in CySS were detected when comparing the data from the first time point with the data from each subsequent time point. Data are expressed as the means ± SEMs; *P<0.05, ** p<0.005, *** p<0.001.</p

Correlations between antioxidant parameters, cytokines and thiols.

*, **, *** indicate significant differences at P < 0.05, P < 0.01, and P < 0.001, respectively.</p

Ingredients and chemical compositions of the basal diets fed during the prestarting (1–9 days), starting (10–21 days), growing (22–35 days) and finishing (35–42 days) phases.

Ingredients and chemical compositions of the basal diets fed during the prestarting (1–9 days), starting (10–21 days), growing (22–35 days) and finishing (35–42 days) phases.</p

Growth performance of the broiler chickens.

In the broiler industry, the average daily gain and feed conversion ratio are extremely favorable, but the birds are beginning to approach the maximum of their genetic capacity. However, as a consequence of strong genetic selection, the occurrence of certain metabolic diseases, such as myopathies, ascites, sudden cardiac death and tibial dyschondroplasia, is increasing. These metabolic diseases can greatly affect the health status and welfare of birds, as well as the quality of meat. The main goal of this study was to investigate the changes in the main parameters of redox homeostasis during the rearing (1–42 days of age) of broilers with high genetic capacity, such as the concentrations of malondialdehyde, vitamin C, vitamin E, and reduced glutathione, the activities of glutathione peroxidase and glutathione reductase, and the inhibition rate of superoxide dismutase. Damage to the transsulfuration pathway during growth and the reason for changes in the level of homocysteine were investigated. Further, the parameters that can characterize the biochemical changes occurring in the birds were examined. Our study is the first characterize plasma albumin saturation. A method was developed to measure the levels of other small molecule thiol components of plasma. Changes in redox homeostasis induce increases in the concentrations of tumor necrosis factor alpha and inflammatory interleukins interleukin 2, interleukin 6 and interleukin 8 in broilers reared according to current large-scale husbandry technology and feeding protocols. A significant difference in all parameters tested was observed on the 21st day. The concentrations of cytokines and homocysteine increased, while the concentrations of glutathione and cysteine in the plasma decreased. Our findings suggest that observed changes in the abovementioned biochemical indices have a negative effect on poultry health.</div

Strains used in the present work.

<p>Strains used in the present work.</p

Representative micrographs of a chicken liver.

(A) Section taken at Day21. (B) Section taken at Day 42.</p