the impact of in ovo injection of silver nanoparticles, thyme and savory extracts in broiler breeder eggs on growth performance, lymphoid-organ weights, and blood and immune parameters of broiler chicks

this study was conducted to evaluate the long-term effects of in ovo injection of nano-silver, thyme and savory extracts in broiler breeder eggs on growth performance, lymphoid organ weights, immune and blood parameters and bone mineral concentration of broiler chicks. a total of 560 fertilized broiler breeder eggs were divided into 7 groups. on d 5 of incubation, eggs were treated with the following groups. group 1 (control, no injection); group 2 (placebo, 1 ml of 0.9% nacl); group 3 and 4 (placebo + 30 and 45 mg of nano-silver, respectively); group 5 and 6 (placebo + 75 and 100 mg of thyme, respectively) and group 7 (placebo + 75 mg of savory). after hatch, chickens were fed a corn-soybean meal diet under the controlled conditions and slaughtered at 14 and 21 d of age for sample collection and analysis. the lymphoid-organ weights and growth rate were not affected by dietary treatments at 14 and 21 d of age. the results also showed that nano-silver injected into broiler breeder eggs during incubation improved the bone mineral concentration and cell-mediated immunity at 14 and 21 d of age, respectively. humoral immunity was improved by thyme and savory extracts (p < 0.05). overall, the effect of in ovo injection of nano-silver, thyme and savory extracts during embryonic development is a potential means to improve immune activities of broiler chickens, while does not have any detrimental effect on embryo hatchability.