On the biological effects of melanin in feeding broiler cross smena 9 chickens (Gallus gallus L.)

Dietary antioxidant adaptogens are of interest to improve health, immune and antioxidant status of intensively growing poultry. This work aimed to comprehensively assess the effect of the adaptogen melanin on feed conversion, biochemical and antioxidant status, and the expression of enzyme genes involved in antioxidant protection and immune response in domestic cross Smena 9 broiler chickens (Gallus gallus L.). The cross resultes from crossing cocks of the Cornish CM56 paternal line with hens of the Plymouth Rock CM79 maternal line. The studies were carried out in the physiological yard of the Ernst Federal Research Center for Animal Husbandry on broiler chickens (n = 42, 50 % hens and 50 % cockerels in each group). From 7 to 45 days, the experimental birds were fed water-soluble dietary melanin at 1.42 mg/kg of live weight (LW). To determine the utilization of feed nutrients, a physiological experiment was carried out on day 35 according to common methods (n = 6 in each group). For the biochemical assessment of pro- and antioxidant status, blood was sampled form 10, 20, and 54 birds slaughtered by decapitation at the age of 12, 26 and 45 days, respectively. The assessed parameters were the concentrations of total protein, albumins, globulins, glucose, triglycerides, bilirubin, cholesterol, calcium, phosphorus, magnesium, iron, chlorides; activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase; the number of red blood cells, the hemoglobin content, hematocrit, the concentration of thiobarbituric acid-reacting substances (TBARS), ceruloplasmin activity (CP), total amount of water-soluble antioxidants (TAWSA), TBARS/CP ratio, reduced glutathione, superoxide dismutase (SOD), catalase, total antioxidant status (TAS). At the end of the experiment, we assessed the relative expression of genes involved in antioxidant defense (AOD), namely catalase CAT , glutathione peroxidase GSH-Gpx , heme oxygenase 1 HO-1 , superoxide dismutase SOD , NF-E2-related transcription factor 2 Nrf2 , and in the immune response, namely avian beta defensin 9 AvBD9 , interleukin 6 IL6 , interleukin 8 IL8 in the caecum and liver of 10 birds from each group. Feeding melanin improved the digestibility of crude fat (CF) by 4.5 % (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }