Effect of Phage Spray on Hatchability and Chick Quality of Eggs Contaminated with Salmonella Typhimurium

<i>Salmonella</i> Typhimurium (<i>S.</i> Typhimurium) contamination poses a significant challenge to breeder egg hatchability and chick health, necessitating the exploration of alternative disinfection methods. This study investigates the potential of phage vB_SPuM_SP02 (SP02) as a novel disinfectant for breeder eggs contaminated with <i>S.</i> Typhimurium SM022. Phage SP02 was isolated from poultry farm effluent and characterized for morphology, biological properties, and genome properties. Experimental groups of specific pathogen-free (SPF) eggs were treated with <i>Salmonella</i> and phage SP02, and efficacy was assessed through hatching rates, chick survival, weight, <i>Salmonella</i> load, immune organ indices, and intestinal flora. Phage treatment effectively eradicated <i>Salmonella</i> contamination on eggshells within 12 h, resulting in increased hatching and survival rates compared to controls. Furthermore, phage treatment mitigated weight loss and tissue <i>Salmonella</i> load in chicks without causing immune organ damage while reducing <i>Salmonella</i> spp. abundance in the intestinal tract. This study demonstrates the potential of phage SP02 as an eco-friendly and efficient disinfectant for <i>S</i>. Typhimurium-contaminated breeder eggs, offering promising prospects for practical application in poultry production.