Noninvasive Heart Rate Measurement Using a Digital Egg Monitor in Chicken and
Turkey Embryos
Abstract: Monitoring the life status of a developing embryo is very useful, especially during last
days of incubation when hatching could potentially be assisted if deemed necessary. A commercially
available digital egg monitor (Buddy, Vetronic Services, Devon, UK) uses noninvasive methodology
to monitor the heart rate of an embryo by measuring the amount of infrared light absorbed by
embryonic blood. Thirty specific pathogen-free (SPF) chicken eggs (29 fertile) were incubated at
37.8 0.1C and the heart rate of each embryo was measured. Heart rates were first detectable in
13 eggs at day 6 of incubation. At day 7, an average heart rate of 170 20 beats/min was detected
in all 29 fertile eggs, which is comparable to reported values. Ten additional SPF chicken eggs
were evaluated at day 13 of incubation to test the effects of ambient temperature changes on
embryonic heart rate. Embryonic heart rates dropped from 262 to 106 beats/min in eggs kept at
room temperature (25C) for 90 minutes and to 60 beats/min after 70 minutes at 5C. Heart rates
increased to 215 beats/min after 75 minutes at the original incubator temperature. Thirty (26 fertile)
incubated turkey eggs were also evaluated with the digital egg monitor. Heart rates in 10 embryos
were first detected at day 9 of incubation. At day 12, embryos had an average heart rate of 234
10 beats/min. The digital egg monitor was also used to measure the heart rate of peregrine falcon(Falco peregrinus) and Northern goshawk (Accipiter gentilis) embryos.