The effects of disinfection of eggs by ultraviolet irradiation on the microbial loads in the incubator and embryonic development in the eggs of Ross-308 broilers
The study was aimed at the comparison and analysis of the efficiency of different methods for the disinfection of air in the incubator and eggshell surface and the effects of these methods on the embryonic development and efficiency of incubation. The experiment was performed on two treatments of eggs of Ross-308 broilers (525 eggs per treatment) incubated in separate incubators. The eggs of control treatment 1 were disinfected prior to incubation by 2% solution of antibiotic Roxacin; eggs of treatment 2 were disinfected by direct UV irradiation using a UV lamp mounted in the side wall of the incubator: prior to incubation by 15 min exposure to 5040 J/m2 and during the incubation (until the internal pipping) by 10 min exposures each 12 hours to 3360 J/m2. It was found that microbial load in the air at days 11, 18, and 20 of incubation in treatment 1 was significantly higher 8.1-; 16.8- and 45.7-fold, respectively, in compare to the level found immediately after the disinfection (p<0.05). Microbial load in the air at days 11, 18, and 20 in treatment 2 was significantly lower by 65.7; 71.8 and 45.7%, respectively, in compare to treatment 1 (p<0.5). The better efficiency of disinfection of eggshell surface was also found in treatment 2. The weight of embryos at days 11 and 18 in treatment 2 was higher by 2.4% (p>0.05) and 5.0% (p<0.05), respectively, in compare to control; however, the direct UV-irradiation of eggs resulted in higher percentages of different categories of embryonic deaths and lower hatch of chicks and hatchability of eggs in compare to control (by 14.83 and 13.65%, respectively) indicating the necessity of further investigation of the methods for UV disinfection of eggs for incubation.