smaller decreases in BW.
When feed was available in the hatching
trays, both chicks and poults began intake. As
is apparent from Figure 1, birds with access to
feed decreased less overall in weight in the
For the chicks, 500 Cobb broiler eggs were
purchased from a 42-wk breeder flock. Eggs
were pre-weighed and selected for an average
weight of 60.0 g (range = 57.7 to 62.5 g), and
these were blocked to two groups by weight
and incubated in setter trays (n = 40, Setter 84,
Petershe, Belgium). At 10 days of incubation
all eggs were candled, and infertile eggs were
removed. Incubating procedure was according
to the Cobb guide. After 436 hr of incubation,
eggs were transferred to hatching trays
and humidity and ventilation changed accord-
Weight egg
Weight egg
ingly. Hatchmg trays were divided down the
middle and starter feed [9] was placed in
troughs in alternate sides of the trays.
Eggs from all trials were weighed at setting
and at transfer. Hatching trays were
examined every 3 hr. Any birds which had
cleared the shell (defined as time of hatch)
were weighed and hatching time recorded. All
birds were weighed after 500 hr for chicks and
668 hr for poults and were then transferred to
floor pens in a temperature controlled facility
with free access to starter feed and water [9].
Groups of birds were sampled from the
peak of hatch and on leaving the hatchery for
proximate carcass analysis.
Data were examined by analysis of
variance using the General Linear Models
procedures of SAS. Differences between
variances were examined using Bartlett’s Test
[lo]. Weight loss data were fitted to a broken
line model as described by Robbins [ll] using
the NLIN procedures of SAS [lo].
RESULTANSD DISCUSSION
Initial egg weight was correlated with
hatch weight for both chicks and poults where
heavier eggs produced heavier birds (Table 1).
Some correlations were also observed between
egg weights and BW at different ages
after hatch (not shown). These relationships
have been shown previously [l]. However,
no correlation was found between the weight
of the egg and time of hatch for either chicks
or poults (Table l), although others have
found sigdcant relationships. Zawalsky [ 121
reported that these correlations were influenced
by the time of storage before incubation.
However, this study used eggs of a
defined weight range from a single flock which
reduced the range of weights and thus influenced
the correlation.
Weight hatch 34.8k8.0 0.69k0.12 0.58
Time hatch o.Ooo1
TABLE 1. Regressions between egg weights, hatching weight