<p>Animal behavior
observation is a widely used method of detecting when animals are ill or
injured, but there are limitations to using behavioral observations. Behavioral
observations can be labor-intensive, subjective and unreliable. The development
of technologies such as accelerometers, which record acceleration and
activity-based data in 3D space, enables faster, more accurate and quantitative
methods of detecting changes in animal behavior. Previous research has
demonstrated the utility of using accelerometers to detect changes in animals’
health and well-being. However, limited information is available on the use of
accelerometers to detect changes in behavior due to heat stress, which is a
major poultry welfare concern, or to detect changes in activity levels of
turkeys. The overall objective of this study was to determine whether
micro-acceleration data loggers (accelerometers) can be used to detect changes
in turkeys’ activity levels and to identify changes in turkey behavior that are
indicative of changes in turkey well-being. Two trials were conducted. Specific
objectives for Trial 1 were to: 1) determine the effects of accelerometers and
habituation to accelerometers on turkey gait and welfare, 2) determine
age-related changes in gait and welfare, and 3) evaluate the validity of the
accelerometers. Thirty-six male commercial turkeys were randomly assigned to
one of five groups: accelerometer and habituation period (AH), accelerometer
and no habituation (AN), VetRap bandage (no accelerometer) and habituation
(VH), bandage (no accelerometer) and no habituation (VN), and nothing on either
leg (C). Welfare was assessed prior to video-recording birds as they walked
across a Tekscan® pressure pad at 8, 12 and 16 wk to determine effects of
treatment on number of steps, cadence,
gait time, gait distance, gait velocity, impulse, gait cycle time, maximum
force, peak vertical pressure, single support time, contact time, step length,
step time, step velocity, stride length, total double support time, and duty
factor. Accelerometer validity and reliability were determined by comparing the
number of steps detected with the accelerometer to the number of steps
determined from video recordings. Several age-related changes in turkey gait
were found regardless of habituation, including a slower cadence at 16 wk,
shorter gait distance at 8 wk, and slower gait velocity at 16wk. Habituation to
the accelerometer and bandage had limited effects on turkey gait:
non-habituated turkeys (VN and AN) spent more time standing on two feet (total
double support time) compared to C birds, but did not differ from habituated
(VH and AH) birds. Accelerometer validity and reliability were affected by both
age and treatment. Validity and reliability were lowest for non-habituated
birds (AN). Precision and sensitivity of accelerometers decreased with age but
were unaffected by treatment. False discovery rate increased, and accuracy and
specificity decreased with age. Results demonstrated that micro-data loggers do
not adversely affect turkey welfare, but habituation to wearing accelerometers
affects accelerometer reliability and validity. Accelerometer validity and
turkey gait are also greatly affected by the age of the turkeys. </p>
<p> </p>
<p>The second experiment
used the validated accelerometers to assess changes in walking activity when
turkeys were under an immune challenge or mild heat stress. Another
objective of Experiment 2 was to identify changes in welfare and behavior
associated with mild heat stress and a mild immune challenge. A total of 92 tom
turkeys (trial 1: 51 turkeys; trial 2: 41 turkeys) were assigned to 3 different
treatments in a crossover design: control (C; no heat stress or immune
challenge), heat stress (HS), and immune challenge (IC). HS treatment was
induced by slowly heating rooms to a peak temperature before slowly returning
the rooms to normal temperatures. IC treatment was induced by a live-virus
hemorrhagic enteritis vaccine which was added to the drinking water. Video
(walking, sitting, standing, eating, drinking, preening, feather pecking,
aggression and heat-stress related behavior) and accelerometer (steps/hr) data
were recorded for 5 days at 10, 12, and 14 wk of age in order to gather
behavior and walking activity data pre and post treatment, which occurred on
day 3 of the 5 day period. Steps/hr decreased
with age, treatments HS and IC had lower step counts compared to control
groups, and each day proved to have a different step count regardless of
whether a treatment was imposed. On the day of the imposed treatments, steps/hr
were lower for both HS and IC turkeys. Welfare analysis indicated that
tail and wing feather condition was worse at 14 wk compared to 10 and 12 wk.
Behaviorally, the amount of time spent sitting increased as birds aged.
Treatment also affected behavior: HS and
IC turkeys performed less standing and walking compared to C birds on the day
of the imposed treatment. Turkeys under a heat stress treatment performed more
aggressive interactions and were observed performing heat-stress related
behavior, including panting and sitting with their wings spread apart. </p>
<p> </p>
<p>Results from
both trials indicated that accelerometers can be useful tools to assess walking
activity of turkeys and that accelerometers have the potential to detect
changes in behavior that may be associated with conditions that negatively
impact turkey welfare. The process of wearing an accelerometer on the leg did
not adversely affect turkey welfare, but habituation is important to ensure
that accelerometers are accurately and reliably recording turkeys’ steps. In
addition, it was determined that changes in behavior, such as decreased walking
and standing, can be indicative of potential welfare issues, such as heat
stress and an immune challenge in turkeys. Further research is needed to
explore the best step threshold for particular turkey ages in order to get the
most accurate data in future analysis of walking activity. Furthermore, sex
differences were not a factor in these studies as only male turkeys were used
which may differ from females in terms of gait and behavior under heat stress
and an immune challenge. It may also be beneficial to further explore turkey
gait as there were discrepancies in the literature and this study concerning
age related differences in gait (duty factor). Future research should focus on
the early detection potential accelerometers can provide to the turkey industry
for welfare concerns. As shown by our results, walking activity decreases under
both a mild heat stress and immune challenge, so future studies should now
determine if this decrease in activity level is detectable before overt visual
behavioral signs. If accelerometers can detect signs of stress more
objectively, accurately, and quicker than visual inspection, then both farmers
and researchers could benefit from utilizing these devices to improve animal
welfare in the future.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/7436783 |
| Date | 16 January 2019 |
| Creators | Rachel A. Stevenson (5930879) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Journal contribution |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Analysis_of_Walking_Activity_as_a_Non-Invasive_Measure_of_Turkey_Well-Being/7436783 |
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