Impacts of Restricting Ribonucleotide Reductase on Performance, Meat Quality, and Intestinal Health in Broiler Chickens Evaluated by Evans Blue Dye

Ribonucleotide reductase (RNR) enzyme is essential for DNA synthesis and overall cellular health. Its inhibition interferes with metabolic pathways and mitochondrial function, leading to increased oxidative damage. Evans blue dye evaluates oxidative damage in tissues by penetrating through ruptured or destabilized membranes, thereby serving as an indicator of cell viability. The present study aimed to investigate the effects of restricting RNR on growth performance, meat quality, and intestinal health in broiler chickens after intestinal development was mainly completed. Twenty male broiler chickens, aged 14 days and weighing 445 ± 5 grams, were randomly divided into two equal groups: a control group and an experimental group, which received an RNR inhibitor (RR) at 20 mg/kg body weight/day for two weeks. Half of the chickens in both groups (5 broiler/group) were injected with Evans blue dye (EB) on the last day of the study. The oxidative damage was measured at the end of the study. The present results indicated that growth performance and feed intake were unchanged during the study. The RNR enzyme increased meat drip loss and lightness while reducing ultimate pH (pHu) compared to the control group. Evans blue concentration increased in the muscle, duodenum, jejunum, and ileum of the experimental group compared to the control group. Although RNR inhibition did not affect growth performance, it led to reduced meat quality and increased oxidative damage. These findings were evidenced by elevated drip loss and increased EB concentration in muscle and in all segments of the small intestine. The present results highlighted the essential role of RNR in maintaining meat quality and tissue integrity of broiler chickens. Keywords: Evans blue dye, Intestine, Meat quality, Ribonucleotide reductase