Role of Exogenous Insulin in Modifying Stress and Carbohydrate Metabolic Gene Expression in Domestic Birds During Slaughter

Abstract

This thesis consists of two parts: the first explores the interplay between cortisol and insulin during the slaughter process in domestic birds, while the second investigates the effect of insulin on the mRNA expression of genes involved in glucose and energy metabolism. The initial study included three bird species: Broiler chickens, Sonali chickens, and Quail. The birds were administered either a control solution or varying doses of insulin (4 IU and 8 IU). Blood samples were collected before and after insulin administration to measure serum cortisol, glucose, and hemoglobin levels. Key findings indicate that insulin administration has species-specific effects on cortisol levels, with Sonali chickens demonstrating a significant reduction in cortisol, suggesting a stressmitigating effect. This led to the second part of the study, which focused on a molecular level of analysis. Using qPCR, tissues from Sonali chickens were examined for the mRNA expression of GLUT12 and the insulin receptor (IR) in the liver and GLUT12 and insulin genes in the pancreas. Molecular analysis revealed that insulin upregulated the mRNA expression of GLUT12, IR, and insulin in Sonali chickens' liver and pancreas, enhancing glucose and energy metabolism. The optimal insulin dose was determined to be 4 IU, which had the most pronounced effects on both hormonal and genetic parameters. These results highlight the potential of dose-dependent insulin and similar product administration to improve welfare and metabolic health in domestic birds.