The effect of In Ovo injection of postbiotics on hatchability, survival, growth performance and intestinal health in broiler chickens raised under heat stress

THE EFFECT OF IN OVO INJECTION OF POSTBIOTICS ON HATCHABILITY, SURVIVAL, GROWTH PERFORMANCE AND INTESTINAL HEALTH IN BROILER CHICKENS RAISED UNDER HEAT STRESS Örtlek O. Aydın Adnan Menderes University, Health Sciences Institute, Animal Nutrition and Nutritional Disorders, Doctorate Thesis, Aydın, 2025. Objective: The aim of this study was to investigate the effects of in ovo injection of postbiotics to broiler chicks' fertilized eggs and addition of powdered postbiotic supplement to post-hatch diets on performance, hot carcass yield, breast meat quality characteristics, some hematological profiles, ileal viscosity, intestinal microbiota, litter characteristics and foot sole scoring under heat stress. Material and Methods: The research was conducted in two separate experiments. A total of 930 fertilized eggs (450 in the first phase and 480 in the second phase) and chicks hatched from these eggs were used. Intestinal contents, blood and breast meat samples, litter materials and performance parameter measurements were collected from the study groups. Two-way Anova test was used to analyze the data. Results: As a result of our current applications, it was determined that in ovo postbiotic supplementation increased feed conversion ratio (P<0.05), decreased triglyceride value (P<0.05) and increased intestinal viscosity values (P<0.05) as a result of postbiotic supplementation in the ration under heat stress. There was no significant effect of the treatments on the other parameters examined. Conclusion: It was concluded that the postbiotic additive used in the study did not cause any negative effects. But some beneficial effects were determined both by in ovo injection method and as a result of its addition to the ration. Keywords: Broiler, in ovo, postbiotic, heat stress.