Influence of bedding material on footpad dermatitis in broiler chickens

© 2009 Poultry Science Association, Inc.
<strong>Influence</strong> <strong>of</strong> <strong>bedding</strong> <strong>material</strong> on footpad
dermatitis in broiler chickens
S. F. Bilgili ,* 1 J. B. Hess ,* J. P. Blake ,* K. S. Macklin ,* B. Saenmahayak ,*
and J. L. Sibley †
* Department <strong>of</strong> Poultry Science, and † Department <strong>of</strong> Horticulture,
Auburn University, Auburn, AL 36849-5416
Primary Audience: Broiler Producers, Service Personnel, Production Managers
SUMMARY
Bedding availability issues are arising rapidly in the broiler industry that may alter the type
and quality <strong>of</strong> <strong>bedding</strong> available to growers to rear broiler chickens. Because birds are in direct
contact with the litter, the potential impact <strong>of</strong> <strong>bedding</strong> <strong>material</strong>s on footpad health is <strong>of</strong>
concern. In 3 successive trials, 8 different <strong>bedding</strong> sources (pine shavings, pine bark, chipped
pine, mortar sand, ground hardwood pallets, chopped straw, ground door filler, and cotton-gin
trash) were compared in side-by-side experimental pens by rearing mixed-sex birds. In addition
to broiler growth performance and litter characteristics (moisture, caking, and ammonia
volatilization), the incidence and severity <strong>of</strong> footpad dermatitis (FPD) was assessed at 6 wk <strong>of</strong>
age. Bedding <strong>material</strong>s had little influence on the live performance <strong>of</strong> broilers in 3 successive
trials. Prevalence <strong>of</strong> FPD varied significantly (P < 0.05) among the <strong>bedding</strong> <strong>material</strong>s. The
incidence <strong>of</strong> FPD paralleled high litter moisture and caking scores, with chipped pine, chopped
straw, cotton-gin trash, and pine shavings showing the highest severity scores and mortar sand
and ground door filler showing the lowest. From an FPD etiology standpoint, the ability <strong>of</strong> the
<strong>bedding</strong> to absorb (i.e., ground door filler) and quickly release (i.e., mortar sand) moisture may
be the most important characteristics.
Key words: broiler , foot , paw , strain-cross
2009 J. Appl. Poult. Res. 18 :583–589
doi: 10.3382/japr.2009-00023
DESCRIPTION OF PROBLEM
The incidence and severity <strong>of</strong> footpad dermatitis
(FPD) is <strong>of</strong> great concern to the broiler
industry, not only from a product quality [1–3],
but also from an animal welfare standpoint [4].
The FPD lesions are usually superficial in nature,
but may result in pain and discomfort to
the bird when transformed into deep ulcers. The
occurrence <strong>of</strong> FPD is now used as an objective
audit criterion in welfare assessment <strong>of</strong> poultry
production systems in both Europe and the
United States [5].
Information on the etiology <strong>of</strong> FPD is limited
and points to a complex interaction <strong>of</strong> various
risk factors, such as production system, stocking
density, market BW, litter quality, flock health,
nutrition, feeding, and flock management programs
[6–14]. Birds spend most <strong>of</strong> their life in
close association with the <strong>bedding</strong> or litter <strong>material</strong>.
Hence, the most obvious contributor to FPD
may be the type, quantity, or substandard qual-
1
Corresponding author: bilgisf@auburn.edu

584
ity <strong>of</strong> <strong>bedding</strong> <strong>material</strong>. Bedding <strong>material</strong>s with
sharp edges (large particle-size wood chips,
chopped straw, etc.) may contribute to FPD
through their abrasive action. Bacterial infection
is not usually observed histologically in FPD lesions.
Litter management is an ongoing struggle
for producers, who must weigh replacement <strong>of</strong>
built-up litter with the cost and availability <strong>of</strong>
alternative <strong>bedding</strong> sources. As birds grow, increasing
amounts <strong>of</strong> moisture and nutrients are
cycled through the litter. Managing litter moisture
becomes more challenging in built-up litter,
especially as the birds approach market BW.
Short downtimes between flocks, marginal flock
health programs, high-nutrient-density feeding
programs, partial-house brooding, evaporative
cooling systems, and poor drinker management
are some <strong>of</strong> the important factors contributing to
this moisture cycle in the rearing environment
[15, 16]. Although many plant-based <strong>material</strong>s
have been evaluated for rearing broiler chickens,
information on their impact on FPD is lacking.
The purpose <strong>of</strong> this study was to evaluate the
influence <strong>of</strong> <strong>bedding</strong> <strong>material</strong> on FPD in broiler
chickens. The incidence and severity <strong>of</strong> FPD
was assessed in broiler chickens grown side-byside
on 8 different <strong>bedding</strong> <strong>material</strong>s with 3 successive
grow-outs.
MATERIALS AND METHODS
In 3 successive trials, 8 alternative <strong>bedding</strong>
<strong>material</strong>s [Figure 1; pine shaving (PS), pine
bark (PB), chipped pine (CP), mortar sand
(MS), chopped wheat straw (CS), ground hardwood
pallets (GP), ground door filler (DF), and
cotton-gin trash (CT)] were compared simultaneously
in a completely randomized experiment
with 6 replicate pens <strong>of</strong> 20 birds each per treatment
[17]. Most <strong>of</strong> these <strong>material</strong>s were periodically
available as a <strong>bedding</strong> source in parts <strong>of</strong>
Alabama. Ground door filler was a wood fiberbased
<strong>material</strong> used in insulating metal doors.
Mixed-sex Ross × Ross [18] birds were reared
to 42 d <strong>of</strong> age (September to December) on a
3-phase commercial feeding program consisting
<strong>of</strong> starter (22.6% CP; 1385 kcal <strong>of</strong> ME/lb),
grower (20.5% CP; 1420 kcal <strong>of</strong> ME/lb), and
finisher (18.3% CP; 1450 kcal <strong>of</strong> ME/lb) feeds.
A 12-d downtime was used between each trial to
simulate commercial practices. Broiler growth
JAPR: Research Report
performance (BW gain, feed consumption, and
mortality) and the incidence (i.e., proportion <strong>of</strong>
affected birds) and severity (i.e., extent <strong>of</strong> lesions)
<strong>of</strong> FPD were measured at the end <strong>of</strong> each
trial by examining the footpads <strong>of</strong> all the birds
[19]. Each <strong>bedding</strong> <strong>material</strong> was analyzed for
bulk density, initial moisture content, and moisture
retention capacity [20]. At the end <strong>of</strong> each
trial, litter was analyzed for percentage <strong>of</strong> moisture
[21]. Litter caking (trials 1 and 2) [22] and
ammonia volatilization (trials 2 and 3) were also
assessed [23]. The data were analyzed using the
GLM procedure <strong>of</strong> SAS [24, 25].
RESULTS AND DISCUSSION
Bulk density, initial moisture content, and
moisture retention characteristics <strong>of</strong> the <strong>bedding</strong>
<strong>material</strong>s used in this study are presented in Table
1. Mortar sand had the highest bulk density,
the lowest initial moisture, and the lowest 24- to
48-h moisture retention values compared with all
other <strong>bedding</strong> <strong>material</strong>s (P < 0.05). In contrast,
chopped wheat straw showed the lowest bulk
density and one <strong>of</strong> the highest initial moisture
levels. Of all the <strong>bedding</strong> <strong>material</strong>s tested, DF
and CT showed the highest moisture retention
ability. Differences between trials in live performance
(i.e., BW gain, FE, and mortality) <strong>of</strong>
broiler chickens in all 3 trials were driven more
by weather than by the <strong>bedding</strong> <strong>material</strong> (data
not shown), indicating that most <strong>of</strong> these locally
available <strong>material</strong>s can be used to rear broiler
chickens, at least for 2 successive flocks.
Figure 2 illustrates litter moisture, litter caking
(trials 1 and 2), and FPD incidence in each
<strong>of</strong> the trials conducted. Incidence <strong>of</strong> FPD varied
significantly (P < 0.05) among the <strong>bedding</strong>
<strong>material</strong>s in trials 1 and 2, but not in trial 3. Because
PS is the preferred <strong>bedding</strong> source in the
United States, the incidence <strong>of</strong> FPD on PS may
be used as a benchmark to assess other <strong>bedding</strong>
<strong>material</strong>s. Incidence <strong>of</strong> FPD on PS increased
from 31 and 26.7%, respectively, in trials 1 and
2 to 54.1% in trial 3. Compared with PS, CP and
CS (trials 1 and 2) and CT (trial 2) showed a
higher incidence <strong>of</strong> FPD. Litter moisture levels
were high in trial 1, ranging from 10.5 (MS) to
39.1% (CP), but stabilized in subsequent trials.
In trials 2 and 3, incidence <strong>of</strong> FPD appeared to
parallel litter moisture levels. Mortar sand had

Bilgili et al.: BEDDING AND FOOTPAD DERMATITIS 585
Figure 1. Bedding <strong>material</strong>s used in trials 1 to 3.
the lowest litter moisture levels (3 and 4.7%),
followed by DF (8.5 and 14%) in trials 2 and 3,
respectively. Both <strong>bedding</strong> <strong>material</strong>s showed the
lowest incidence and severity <strong>of</strong> FPD. Bilgili et
al. [26, 27] previously reported on the use <strong>of</strong> MS
as <strong>bedding</strong> for rearing broilers and the beneficial
effect it had on FPD as compared with PS. Litter
caking scores closely followed FPD incidence
in trials 1 and 2 (Figure 2). This was not surprising
because litter moisture and caking have been
identified as major contributing factors to FPD
in poultry [15, 16]. Mayne et al. [16] clearly
demonstrated that high litter moisture alone was
sufficient to cause FPD in young turkeys in as
little as 2 to 4 d.
Litter ammonia may be another important
factor in the etiology <strong>of</strong> FPD [28] because the
ammonia generated because <strong>of</strong> bacterial action
dissolves in high-moisture litter to create an irritant
alkaline solution for the footpads. Ammonia
Table 1. Physical characteristics <strong>of</strong> <strong>bedding</strong> <strong>material</strong>s
Moisture retention (%)
Bedding <strong>material</strong> Bulk density (g/cm 3 ) Initial moisture (%)
24 h 48 h
Pine shavings 0.110 cde 11.3 bc 71.2 c 71.8 c
Pine bark 0.198 b 11.4 bc 68.6 c 73.8 c
Chipped pine 0.064 ef 14.5 a 73.0 c 74.4 c
Mortar sand 1.234 a 9.9 c 25.8 d 22.2 d
Ground hardwood pallets 0.130 cd 13.2 ab 78.0 b 80.2 b
Chopped straw 0.040 f 12.2 abc 80.6 b 80.8 b
Ground door filler 0.158 bc 11.2 bc 87.4 a 88.0 a
Cotton-gin trash 0.096 def 12.0 bc 87.6 a 88.4 a
SEM 1 0.013 0.43 1.0 1.03
Significance *** *** *** ***
a–f Means within a column with different superscripts differ (P < 0.05).
1 Pooled SEM.
***P < 0.001.

586
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Figure 2. Incidence <strong>of</strong> footpad dermatitis (FPD) and litter moisture (trials 1 to 3).
volatilization varied from 69 to 99 ppm in trial
2, and from 65 to 105 ppm in trial 3, with no difference
(P > 0.05) among the <strong>bedding</strong> sources
(data not shown). Tasistro et al. [29] recently
observed a significant interaction between <strong>bedding</strong>
<strong>material</strong>s and sampling site on ammonia
volatilization that was attributed to differences
in moisture retention capacity. It was postulated
that <strong>bedding</strong> <strong>material</strong>s with lower moisture retention
would dry and form a crust faster, thus

Bilgili et al.: BEDDING AND FOOTPAD DERMATITIS 587
Figure 3. Severity <strong>of</strong> footpad dermatitis (FPD; trials 1 to 3).

588
creating a physical barrier to ammonia volatilization.
Based on the ammonia levels and caking
scores observed in this study, this hypothesis
was not confirmed. Nagaraj et al. [12], using
high-protein diets, linked high litter nitrogen
levels to FPD. In several studies, nutritional and
management approaches to reduce nitrogen excretion
and control litter ammonia production
appeared to alleviate FPD incidence and severity
[13, 14].
The severity scores <strong>of</strong> FPD are presented in
Figure 3. Overall, FPD severity increased with
each successive trial. Proportionately, in addition
to CP and CS (trials 1, 2, and 3), CT (trials 2
and 3) and PS (trial 3) <strong>bedding</strong> <strong>material</strong>s showed
the highest FPD severity. Again, MS and DF
were ranked as the <strong>bedding</strong> <strong>material</strong>s with the
lowest severity. These results are consistent
with those recently reported by Berk [30], who
showed wide variation among different kinds <strong>of</strong>
litter in the prevalence and severity <strong>of</strong> FPD. In
this study, both CS and CP had the worst FPD
scores.
It is clear from this study that the <strong>bedding</strong>
<strong>material</strong>s tested in this study are acceptable for
rearing broilers, at least for several flocks. Pine
bark has been used successfully under commercial
conditions, with the intent <strong>of</strong> using the used
litter as a substrate component in nursery crop
production [31]. Chipped pine, GP, DF, and CT
are unique plant-based products that may be
available locally to broiler producers as substitute
<strong>bedding</strong> <strong>material</strong>s. However, based on the
results obtained in this study and those reported
by others [16, 30], <strong>bedding</strong> <strong>material</strong>s can influence
the prevalence and severity <strong>of</strong> FPD in
broiler chickens. This effect may be directly
associated with the ability <strong>of</strong> <strong>bedding</strong> to shield
footpads from continuous contact with moisture,
thereby minimizing footpad s<strong>of</strong>tening and susceptibility
to irritation and inflammation. Birds
reared on MS and DF showed the lowest PDF
scores in all 3 trials. However, both <strong>of</strong> these <strong>bedding</strong>
<strong>material</strong>s exhibited significantly contrasting
physical characteristics. Although MS had a
low (26%) 24-h moisture retention ability and
DF had one <strong>of</strong> the highest (87%; Table 1), both
<strong>bedding</strong> <strong>material</strong>s showed some <strong>of</strong> the lowest
litter moisture and caking levels observed in this
study. In terms <strong>of</strong> FPD control, the capability <strong>of</strong>
the <strong>bedding</strong> to absorb (i.e., DF) and release (i.e.,
JAPR: Research Report
MS) moisture may be the most important characteristics
to seek in a <strong>bedding</strong> <strong>material</strong>.
CONCLUSIONS AND APPLICATIONS
1. The <strong>bedding</strong> <strong>material</strong>s evaluated had
little influence on the live performance
<strong>of</strong> broilers in 3 successive trials.
2. Footpad dermatitis incidence and severity
varied significantly (P < 0.05) among
the <strong>bedding</strong> <strong>material</strong>s and corresponded
to high litter moisture and caking scores.
Of the <strong>bedding</strong> <strong>material</strong>s tested, CP, CS,
CT, and PS showed the highest FPD incidence
and severity, whereas MS and
DF had the lowest.
3. From the standpoint <strong>of</strong> FPD etiology, the
ability <strong>of</strong> the <strong>bedding</strong> to absorb (i.e., DF)
and quickly release (i.e., MS) moisture
may be the most important characteristics.
REFERENCES AND NOTES
1. Bilgili, S. F., and J. B. Hess. 1997. Maximizing chicken
paw yield and quality . Meat Poult. 5 :54.
2. Bilgili, S. F., M. A. Alley, J. B. Hess, and M. Nagaraj.
2006. <strong>Influence</strong> <strong>of</strong> age and sex on foot pad quality and yield
in broiler chickens reared on low and high density diets. J.
Appl. Poult. Res. 15:433–441.
3. Bilgili, S. F., D. Zelenka, and J. E. Marion. 2008.
Quality standards for chicken feet (paws) during processing.
In Proc. World’s Poultry Congress, Brisbane, Australia [CD-
ROM]. World’s Poultry Science Association, Beekbergen,
the Netherlands.
4. Bradshaw, R. H., R. D. Kirkden, and D. M. Broom.
2002. A review <strong>of</strong> the aetiology and pathology <strong>of</strong> leg weakness
in broilers in relation to welfare. Avian Poult. Biol.
Rev. 13:45–103.
5. National Chicken Council. 2005. National Chicken
Council Animal Welfare Guidelines and Audit Checklist.
Natl. Chicken Counc., Washington, DC. http://www.nationalchickencouncil.com/aboutIndustry/detail.cfm?id=19
Accessed
March 25, 2009.
6. Menzies, F. D., E. A. Goodall, D. A. McConaghy,
and M. J. Alcorn. 1998. An update on the epidemiology <strong>of</strong>
contact dermatitis in commercial broilers. Avian Pathol.
27:174–180.
7. Ekstrand, C., T. E. Carpenter, I. Andersson, and B.
Algers. 1998. Prevalence and control <strong>of</strong> foot-pad dermatitis
in broilers in Sweden. Br. Poult. Sci. 39:318–324.
8. Mayne, R. K. 2005. A review <strong>of</strong> the aetiology and
possible causative factors <strong>of</strong> foot pad dermatitis in growing
turkeys and broilers. World’s Poult. Sci. J. 61:256–267.
9. Pagazaurtundua, A., and P. D. Warris. 2006. Levels <strong>of</strong>
foot pad dermatitis in broiler chickens reared in 5 different
systems. Br. Poult. Sci. 47:529–532.
10. Haslam, S. M., T. G. Knowles, S. N. Brown, L. J.
Wilkins, S. C. Kestin, P. D. Warris, and C. J. Nicol. 2007.

Bilgili et al.: BEDDING AND FOOTPAD DERMATITIS 589
Factors affecting the prevalence <strong>of</strong> foot pad dermatitis,
hock burn and breast burn in broiler chicken. Br. Poult. Sci.
48:264–275.
11. Meluzzi, A., C. Fabbri, E. Folegatti, and F. Sirri.
2008. Survey <strong>of</strong> chicken rearing conditions in Italy: Effects
<strong>of</strong> litter quality and stocking density on productivity, foot
dermatitis and carcase injuries. Br. Poult. Sci. 49:257–264.
12. Nagaraj, M., C. A. P. Wilson, J. B. Hess, and S. F.
Bilgili. 2007. Effect <strong>of</strong> high protein and all vegetable diets
on the incidence and severity <strong>of</strong> pododermatitis in broiler
chickens. J. Appl. Poult. Res. 16:304–312.
13. Nagaraj, M., J. B. Hess, and S. F. Bilgili. 2007.
Evaluation <strong>of</strong> a feed-grade enzyme in broiler diets to reduce
pododermatitis. J. Appl. Poult. Res. 16:52–61.
14. Nagaraj, M., C. A. P. Wilson, B. Saenmahayak, J. B.
Hess, and S. F. Bilgili. 2007. Efficacy <strong>of</strong> a litter amendment
to reduce pododermatitis in broiler chickens. J. Appl. Poult.
Res. 16:255–261.
15. Wang, G., C. Ekstrand, and J. Svedberg. 1998. Wet
litter and perches as risk factors for the development <strong>of</strong> foot
pad dermatitis in floor-housed hens. Br. Poult. Sci. 39:191–
197.
16. Mayne, R. K., R. W. Else, and P. M. Hocking. 2007.
High litter moisture is sufficient to cause footpad dermatitis
in growing turkeys. Br. Poult. Sci. 48:538–545.
17. Each <strong>bedding</strong> <strong>material</strong> was placed 4 in. deep in 6 replicate
pens (1.22 × 1.52 m in dimension), with a stocking
density <strong>of</strong> 10.8 birds per m 2 .
18. Aviagen, Huntsville, AL.
19. The FPD scoring system was a 3-point visual ranking
system, where a score <strong>of</strong> 0 indicated footpads with no lesions
present, and intact dermal ridges within central plantar
footpad surface; a score <strong>of</strong> 1 indicated footpads with mild
lesions, and dermal ridges with oval or round ulcers covered
with a crust (7.5 mm) adhering
to the central plantar footpad [14].
20. Bulk density was determined by calculating grams
<strong>of</strong> dry sample per cubic centimeter. The dry weight <strong>of</strong> each
<strong>material</strong> was determined after drying for 72 h at 71°C. Five
20-g samples from each <strong>bedding</strong> <strong>material</strong> were placed in
nylon socks and fully submerged in water for 24 and 48
h. At the end <strong>of</strong> each interval, the socks were hung, gently
massaged to drip, allowed to air-dry for 30 min, and subsequently
reweighed.
21. Litter was collected from the 4 corners and center <strong>of</strong>
each replicate pen and pooled in plastic bags to create a composite
sample for moisture analysis. Percentage <strong>of</strong> moisture
was determined by placing 2 g <strong>of</strong> litter into a drying oven
(150°C) for 24 h. Samples were then immediately placed
into desiccators, and weighed after equilibration <strong>of</strong> temperature
to calculate percentage <strong>of</strong> moisture.
22. Litter caking was evaluated subjectively by stirring
the litter with a rod to estimate the caked area as a percentage
<strong>of</strong> the total pen surface.
23. Ammonia measurements were conducted using
a closed container <strong>of</strong> specified dimensions (36 × 46 × 12
cm) inverted over the litter bed and were determined using
a Drager CMS Analyzer (Drager Inc., Pittsburgh, PA)
equipped with a remote air-sampling pump and ammonia
sampling chip (10 to 150 ppm). The tube from the sampling
pump was located in the top center <strong>of</strong> the container. The sampling
pump was evacuated (calibrated) for 60 s, followed by
a measurement period <strong>of</strong> up to 300 s. Most readings were
usually achieved within 60 s after evacuation.
24. The statistical model consisted <strong>of</strong> a 1-way ANOVA,
with pens (treatment) as the error term to test the <strong>bedding</strong>
<strong>material</strong> main effect. When significant (P < 0.05), means
were separated by Tukey’s test. Percentage values were
transformed to arcsine values before analysis. Each trial was
analyzed separately.
25. SAS Institute. 1988. SAS/STAT User’s Guide for Personal
Computers, Release 6.03. SAS Inst. Inc., Cary, NC.
26. Bilgili, S. F., G. I. Montenegro, J. B. Hess, and M. K.
Eckman. 1999. Sand as litter for rearing broiler chickens. J.
Appl. Poult. Res. 8:345–351.
27. Bilgili, S. F., G. I. Montenegro, J. B. Hess, and M.
K. Eckman. 1999. Live performance, carcass quality, and
deboning yields <strong>of</strong> broilers reared on sand as a litter source.
J. Appl. Poult. Res. 8:352–361.
28. Haslam, S. M., S. N. Brown, L. J. Wilkins, S. C. Kestin,
P. D. Warriss, and C. J. Nicol. 2006. Preliminary study to
examine the utility <strong>of</strong> using foot burn or hock burn to assess
aspects <strong>of</strong> housing conditions for broiler chicken. Br. Poult.
Sci. 47:13–18.
29. Tasistro, A. S., C. W. Ritz, and D. E. Kissel. 2007.
Ammonia emissions from broiler litter: response to <strong>bedding</strong>
<strong>material</strong>s and acidifiers. Br. Poult. Sci. 48:399–405.
30. Berk, J. 2008. Effect <strong>of</strong> different kinds <strong>of</strong> litter on severity
and prevalence <strong>of</strong> pododermatitis in male broilers. In
Proc. XXIII World’s Poult. Congr., Brisbane, Australia [CD-
ROM]. World’s Poultry Science Association, Beekbergen,
the Netherlands.
31. Pickens, J. M., J. L. Sibley, C. H. Gilliam, S. F. Bilgili,
J. B. Hess, K. S. Macklin, and J. O. Donald. 2009. Evaluation
<strong>of</strong> bark-based poultry litter as a substrate component
in nursery crop production. Proc. Southern Nursery Assoc.
Res. Conf. 54:121–123.