Effect of using colloidal silver in the disinfection of hatching eggs on some microbial, hatchability and performance traits in Japanese quail (Coturnix cot. japonica)

The aim of this study was to evaluate the effect of colloidal silver as disinfectant of Japanese quail hatching eggs on hatchability traits, eggshell conductance, hatched chicken quality and microbial populations on the shell surface. In total, 360 Japanese quail hatching eggs were distributed into 3 equal groups before incubation. Before being placed into the incubator the eggs from Group 1 were not disinfected (NC) and eggs of Group 2 were disinfected with formalin and permanganate (C). In Group 3, colloidal silver (S, Nano-Koloid (R)) was applied in 50 mg/kg concentration by spraying. The eggs were hatched in a BIOS hatching apparatus under standard conditions. After 14 days of incubation the eggs were candled to determine the number of infertile eggs and dead embryos. Samples for microbial analyses were collected. After 17.5 days of incubation fertility, hatchability, periodical embryonic mortality and eggshell conductance were determined. Thereafter, chickens were reared for 14 days and mortality and body weight (bw) were registered at 7th and 14th day of rearing. The results of the microbial analyses partially confirmed the antimicrobial properties of colloidal silver. Using this preparation reduced the number of bacterial colonies of almost all species after 15 days of incubation. It did not create preferential conditions for development of any particular bacteria strain, as opposed to formalin. In group C Staphylococcus spp. dominated. Hatching results of eggs disinfected with colloidal silver were similar to groups C and NC. The use of colloidal silver resulted in significant changes in eggshell conductivity of fertile eggs and thus in a lower loss of moisture. In group S lower mortality and considerably higher body weights were reached within 14 days of rearing.