Preincubation Heat Treatment of Chicken Hatching Eggs to Inactivate Mycoplasma

Abstract

Eggs from chickens experimentally infected with Mycoplasma gallisepticum were heated for 11-15 hr in an incubator containing approximately 2,000 medium-sized eggs and were removed for normal incubation once they reached internal temperatures of 110117 F. After 14 days of normal incubation, all heated and control infected eggs were cultured for M. gallisepticum. Normal control eggs were employed with each heating run to determine hatchability. It was concluded that M. gallisepticum could be inactivated when infected hatching eggs reached an internal temperature of 114 F within 12-14 hr if the eggs were started at room temperature (78 F) and the incubator heater was on constantly with no thermostat control. Hatchability was usually reduced approximately 8-12%o. Results were similar with M. synoviae except that a slightly higher temperature was necessary. It is suggested that just reaching an internal egg temperature of 114.5 F during a 12-to-14-hour preincubation heating period without thermostat control should inactivate M. gallisepticum and M. synoviae in infected chicken hatching eggs.