RESUMEN
The main reason preventing broiler chickens from reaching their genetic potential and hurting their performance in the tropics is heat stress. This study aimed to ascertain how Justicia carnea leaf powder (JLP) supplementation affects broiler chickens' performance, blood indices, antioxidant status, and gut microflora in tropical environments. A completely randomized method was used to assign 240 Cobb 500 broiler chicks to the experimental diets (6 replicates per diet, 10 birds per replication). Diet 1 included no supplement (negative control), diet 2 included 200 mg/kg vitamin C (positive control), diet 3 included 2,500 mg/kg JLP, and diet 4 included 5,000 mg/kg JLP. On day 42, the body weight gain (BWG) of the birds fed on diet 4 was significantly higher than those on diet 1. The packed cell volume, red blood cell count, and hemoglobin concentration of the birds fed on diets 3 and 4 were significantly higher than those of the control (P<0.05). The serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and cholesterol were lower in birds fed on diets 3 and 4, compared to those on diet 1 (P<0.05). The serum heat shock protein 70 (HSP 70) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were lower in birds fed on diets 3 and 4, compared to those on diet 1 (P<0.05). The lactic acid-producing bacteria (LAB) population was higher in birds fed on diets 3 and 4, compared to those on diet 1(P<0.05). However, the Coliform bacteria population was reduced in birds fed on diets 3 and 4, compared to those on diet 1. The 2,500 and 5,000 mg/kg JLP dietary supplementations enhanced BWG, improved erythrogram indices, and reduced blood AST, ALT, cholesterol, HSP 70, 8-OHdG, and caeca Coliform population but increased the caeca LAB population.