Post-hatching behaviour
of turkey poults: Life without mom
L. Panning and I.J.H. Duncan
University of Guelph,
Guelph, Canada
"Starve-out" is defined
as the failure of turkey poults to initiate feeding and is claimed to cause
2-6% mortality of commercially-kept poults in the first eight days of life.
The cause of starve-out is unknown but it has frequently been blamed on
the poults' inability to learn to feed. The general approach was
to observe and record the feeding behaviour of 200 individually-marked,
one-day-old, male, Hybrid poults from their first exposure to food and
water for 7 days. The birds were kept in groups of 10 and there were 4
groups in each of 5 repetitions. The birds were kept in constant
light
for 7 days. Latency
for each individual to initiate feeding and drinking was recorded using
videotape. All individuals ate within 90 minutes and drank within
10 minutes. All individuals were weighed at the end of each day and
this confirmed that they had actually consumed food. None of the
200 birds showed any difficulty in finding food and water and consuming
it and none starved. This suggests that the cause of starve-out is
not a learning problem. Patterns of group feeding were investigated
by recording pecking behaviour for each group using a purpose-built device
called a peck-rate analyzer**. This device detects pecks at each
of four feeders and transduces the mechanical vibration of
each peck into an electric
wave which then passes to the analyzer. The system can detect pecks
to a maximum of 3200 pecks/minute and records the pecking activity at each
feeder on minute-by-minute basis. These records were analysed for
temporal patterns of activity. The analyses revealed that feeding
behaviour of newly hatched poults is characterized by two types of rhythm
(a) a circadian rhythm of approximately 24 hours and (b) a much shorter
ultradian rhythm. All twenty groups demonstrated similar strong circadian
patterns of feeding for at least 48 hours after being placed on experiment
despite being kept in continuous light. In addition, all groups demonstrated
ultradian rhythms of feeding
consisting of short bouts
of feeding alternating with non-feeding. The data suggest that feeding
behaviour of newly hatched poults is complex and deserves further investigation.
They suggest that the actual initiation of feeding and drinking is not
problematic, at least for healthy birds and that starve-out is probably
not caused by a learning deficit. Further, the fact that there is
a strong circadian rhythm for feeding from hatching (or very soon after
hatching), suggests that the husbandry practice of leaving birds in continuous
light in order to stimulate feeding, may require re-examination.
** Technical information
on the peck-rate analyzer is available from Wolfgang Panning, Department
of Chemistry, University of Toronto, Canada (Telephone: 416 978 5257 or
416 763 2668).