RESUMO
The aim of this study was to investigate the effects of the in ovo feeding of green nanoparticles of silver (Nano-Ag), probiotics, and their combination on hatchability, carcass criteria and internal organs, biochemical parameters, and cecal microbial populations in hatched one-day-old chicks. On day 18 of incubation, 250 live embryo eggs were weighed and randomly assigned to one of five treatment groups: a negative control group, a positive control group consisting of chicks injected with 0.2 mL physiological saline, a group consisting of chicks injected with 0.2 mL Nano-Ag, a group consisting of chicks injected with 0.2 mL probiotics (Bifidobacterium spp.), and a group consisting of chicks injected with 0.2 mL combination of Nano-Ag and probiotics (1:1). The results showed that the in ovo injection of Nano-Ag or probiotics, alone or in combination, had no effect on hatchability, live body weight, or internal organs but improved (p < 0.05) chick carcass yield compared to the control groups. Furthermore, in ovo feeding decreased (p < 0.05) serum levels of cholesterol, triglycerides, urea, creatinine, alanine aminotransferase, and aspartate aminotransferase, as well as cecal E. coli, but increased Bifidobacterium spp. when compared to the control groups. Based on these findings, in ovo injections of green Nano-Ag and probiotics, either alone or in combination, have the potential to improve chick health and balance the microbial populations in hatched one-day-old chicks.