monitoring environmental conditions during incubation ... - ISAH-SOC

categories’ as the main effects. A significance level of 0.05
was used. Means were compared using Student-Newman-
Keuls multiple range (SNK) test contrasts (SAS Institute
Inc., 1990).
RESULTS
1. Hatching parameters
Hatching parameters are summarized in Table 1.
Hatchability was similar for both groups. When day-old
chick quality scores were taken into account, the
percentage of first class chick in control group was
significantly higher than that in test group.
Table 1. Fertility, hatchability and first class chick proportion
Test Group
Fertility 1 (%) 90.48 94.88
Hatchability 2 (%) 74.18 75.19
First Class Chick 3 (%) 86.19 98.97
1
Fertility expressed as percentage of eggs set.
2
Hatchability expressed as percentage of fertile eggs.
3
First Class Chick expressed as percentage of hatching chicks.
control Group
2. Eggshell temperature (EST)
The status of the eggs with attached temperature sensors
was determined after hatch. There were three categories
of eggs: unfertilized (UN), dead embryos (D), and
hatching chicks (H). The EST of 3 categories of eggs
showed no significant difference during the first 11 days.
However, egg status showed difference in EST at day 18,
19 and 20 (Table 2). The EST of hatching eggs is higher
than the EST of eggs with dead embryos and unfertilised
eggs (P ≤ 0.05).
Table 2. Eggshell temperature of three egg categories
Incubation time(day) H-mean D-mean UN-mean
18 37.3±0.12 a 36.6±0.12 b 36.43±0.15 b
19 38.32±0.13 a 37.64±0.13 b 37.47±0.16 b
20 37.7±0.12 a 37.09±0.12 b 36.97±0.15 b
3. Hatching process
The hatching time of first chick in the control group is at
day 19 and 11 hours (19.11) compared to 19.22 in the
test group (11 hours later (). Most chicks had hatched by
20.17 in the control group compared to 21.06 in the test
group. Thus the total length of hatching times (hatch
window) for control and test groups are 30 hours and 32
hours, respectively?
Figure 3. Number of hatching chicks at different incubation time
DISCUSSION
Temperature sensors capture the EST during the complete
incubation and show the division of EST of three egg
statuses (unfertilised, dead and hatching). Due to an
increased metabolism, piping action and hatching
movement, the embryo increases heat production at the
latter part of incubation which maintains the eggshell
temperature during transfer, at day 19 and 20. Thus EST
is significant lower in eggs housing dead embryos and