©2009 Poultry Science Association, Inc.
Influence of bedding material 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 of Poultry Science, and †Department of 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 of bedding available to growers to rear broiler chickens. Because birds are in direct contact with the litter, the potential impact of bedding materials on footpad health is of
concern. In 3 successive trials, 8 different bedding 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 of footpad dermatitis (FPD) was assessed at 6 wk of
age. Bedding materials had little influence on the live performance of broilers in 3 successive
trials. Prevalence of FPD varied significantly (P < 0.05) among the bedding materials. The
incidence of 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 of the
bedding 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 of footpad dermatitis (FPD) is of 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 of FPD is now used as an objective
audit criterion in welfare assessment of poul1
Corresponding author: [email protected]
try production systems in both Europe and the
United States [5].
Information on the etiology of FPD is limited
and points to a complex interaction of 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 of their life in
close association with the bedding or litter material. Hence, the most obvious contributor to FPD
may be the type, quantity, or substandard qual-
JAPR: Research Report
584
ity of bedding material. Bedding materials 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 of
built-up litter with the cost and availability of
alternative bedding sources. As birds grow, increasing amounts of 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 of the important factors contributing to
this moisture cycle in the rearing environment
[15, 16]. Although many plant-based materials
have been evaluated for rearing broiler chickens,
information on their impact on FPD is lacking.
The purpose of this study was to evaluate the
influence of bedding material on FPD in broiler
chickens. The incidence and severity of FPD
was assessed in broiler chickens grown side-byside on 8 different bedding materials with 3 successive grow-outs.
MATERIALS AND METHODS
In 3 successive trials, 8 alternative bedding
materials [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 of 20 birds each per treatment [17]. Most of these materials were periodically available as a bedding source in parts of
Alabama. Ground door filler was a wood fiberbased material used in insulating metal doors.
Mixed-sex Ross × Ross [18] birds were reared
to 42 d of age (September to December) on a
3-phase commercial feeding program consisting of starter (22.6% CP; 1385 kcal of ME/lb),
grower (20.5% CP; 1420 kcal of ME/lb), and
finisher (18.3% CP; 1450 kcal of ME/lb) feeds.
A 12-d downtime was used between each trial to
simulate commercial practices. Broiler growth
performance (BW gain, feed consumption, and
mortality) and the incidence (i.e., proportion of
affected birds) and severity (i.e., extent of lesions) of FPD were measured at the end of each
trial by examining the footpads of all the birds
[19]. Each bedding material was analyzed for
bulk density, initial moisture content, and moisture retention capacity [20]. At the end of each
trial, litter was analyzed for percentage of 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 of SAS [24, 25].
RESULTS AND DISCUSSION
Bulk density, initial moisture content, and
moisture retention characteristics of the bedding
materials 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 bedding materials (P < 0.05). In contrast,
chopped wheat straw showed the lowest bulk
density and one of the highest initial moisture
levels. Of all the bedding materials tested, DF
and CT showed the highest moisture retention
ability. Differences between trials in live performance (i.e., BW gain, FE, and mortality) of
broiler chickens in all 3 trials were driven more
by weather than by the bedding material (data
not shown), indicating that most of these locally
available materials 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
of the trials conducted. Incidence of FPD varied significantly (P < 0.05) among the bedding
materials in trials 1 and 2, but not in trial 3. Because PS is the preferred bedding source in the
United States, the incidence of FPD on PS may
be used as a benchmark to assess other bedding
materials. Incidence of 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 of 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 of FPD appeared to
parallel litter moisture levels. Mortar sand had
Bilgili et al.: BEDDING AND FOOTPAD DERMATITIS
585
Figure 1. Bedding materials 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 bedding materials showed the
lowest incidence and severity of FPD. Bilgili et
al. [26, 27] previously reported on the use of MS
as bedding 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 of FPD [28] because the
ammonia generated because of bacterial action
dissolves in high-moisture litter to create an irritant alkaline solution for the footpads. Ammonia
Table 1. Physical characteristics of bedding materials
Moisture retention (%)
Bedding material
Pine shavings
Pine bark
Chipped pine
Mortar sand
Ground hardwood pallets
Chopped straw
Ground door filler
Cotton-gin trash
SEM1
Significance
a–f
Bulk density (g/cm3)
Initial moisture (%)
cde
0.110
0.198b
0.064ef
1.234a
0.130cd
0.040f
0.158bc
0.096def
0.013
***
Means within a column with different superscripts differ (P < 0.05).
Pooled SEM.
***P < 0.001.
1
bc
11.3
11.4bc
14.5a
9.9c
13.2ab
12.2abc
11.2bc
12.0bc
0.43
***
24 h
48 h
c
71.2
68.6c
73.0c
25.8d
78.0b
80.6b
87.4a
87.6a
1.0
***
71.8c
73.8c
74.4c
22.2d
80.2b
80.8b
88.0a
88.4a
1.03
***
JAPR: Research Report
586
Figure 2. Incidence of 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 bedding sources
(data not shown). Tasistro et al. [29] recently
observed a significant interaction between bed-
ding materials and sampling site on ammonia
volatilization that was attributed to differences
in moisture retention capacity. It was postulated
that bedding materials with lower moisture retention would dry and form a crust faster, thus
Bilgili et al.: BEDDING AND FOOTPAD DERMATITIS
Figure 3. Severity of footpad dermatitis (FPD; trials 1 to 3).
587
JAPR: Research Report
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 of 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) bedding materials showed
the highest FPD severity. Again, MS and DF
were ranked as the bedding materials with the
lowest severity. These results are consistent
with those recently reported by Berk [30], who
showed wide variation among different kinds of
litter in the prevalence and severity of FPD. In
this study, both CS and CP had the worst FPD
scores.
It is clear from this study that the bedding
materials 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 of 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 bedding materials. However, based on the
results obtained in this study and those reported
by others [16, 30], bedding materials can influence the prevalence and severity of FPD in
broiler chickens. This effect may be directly
associated with the ability of bedding to shield
footpads from continuous contact with moisture,
thereby minimizing footpad softening and susceptibility to irritation and inflammation. Birds
reared on MS and DF showed the lowest PDF
scores in all 3 trials. However, both of these bedding materials exhibited significantly contrasting physical characteristics. Although MS had a
low (26%) 24-h moisture retention ability and
DF had one of the highest (87%; Table 1), both
bedding materials showed some of the lowest
litter moisture and caking levels observed in this
study. In terms of FPD control, the capability of
the bedding to absorb (i.e., DF) and release (i.e.,
MS) moisture may be the most important characteristics to seek in a bedding material.
CONCLUSIONS AND APPLICATIONS
1. The bedding materials evaluated had
little influence on the live performance
of broilers in 3 successive trials.
2. Footpad dermatitis incidence and severity varied significantly (P < 0.05) among
the bedding materials and corresponded
to high litter moisture and caking scores.
Of the bedding materials tested, CP, CS,
CT, and PS showed the highest FPD incidence and severity, whereas MS and
DF had the lowest.
3. From the standpoint of FPD etiology, the
ability of the bedding 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. Influence of 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 [CDROM]. World’s Poultry Science Association, Beekbergen,
the Netherlands.
4. Bradshaw, R. H., R. D. Kirkden, and D. M. Broom.
2002. A review of the aetiology and pathology of 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 of
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 of foot-pad dermatitis
in broilers in Sweden. Br. Poult. Sci. 39:318–324.
8. Mayne, R. K. 2005. A review of the aetiology and
possible causative factors of 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 of
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
Factors affecting the prevalence of 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 of chicken rearing conditions in Italy: Effects
of 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 of high protein and all vegetable diets
on the incidence and severity of pododermatitis in broiler
chickens. J. Appl. Poult. Res. 16:304–312.
13.Nagaraj, M., J. B. Hess, and S. F. Bilgili. 2007.
Evaluation of 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 of 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 of 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 bedding material was placed 4 in. deep in 6 replicate pens (1.22 × 1.52 m in dimension), with a stocking
density of 10.8 birds per m2.
18.Aviagen, Huntsville, AL.
19.The FPD scoring system was a 3-point visual ranking
system, where a score of 0 indicated footpads with no lesions present, and intact dermal ridges within central plantar
footpad surface; a score of 1 indicated footpads with mild
lesions, and dermal ridges with oval or round ulcers covered
with a crust (<7.5 mm); and a score of 2 indicated footpads
with severe lesions, with a dark brown crust (>7.5 mm) adhering to the central plantar footpad [14].
20.Bulk density was determined by calculating grams
of dry sample per cubic centimeter. The dry weight of each
material was determined after drying for 72 h at 71°C. Five
20-g samples from each bedding material were placed in
nylon socks and fully submerged in water for 24 and 48
h. At the end of 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 of
each replicate pen and pooled in plastic bags to create a composite sample for moisture analysis. Percentage of moisture
was determined by placing 2 g of litter into a drying oven
589
(150°C) for 24 h. Samples were then immediately placed
into desiccators, and weighed after equilibration of temperature to calculate percentage of moisture.
22.Litter caking was evaluated subjectively by stirring
the litter with a rod to estimate the caked area as a percentage
of the total pen surface.
23.Ammonia measurements were conducted using
a closed container of 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 of the container. The sampling pump was evacuated (calibrated) for 60 s, followed by
a measurement period of up to 300 s. Most readings were
usually achieved within 60 s after evacuation.
24.The statistical model consisted of a 1-way ANOVA,
with pens (treatment) as the error term to test the bedding
material 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 of 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 of using foot burn or hock burn to assess
aspects of 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 bedding
materials and acidifiers. Br. Poult. Sci. 48:399–405.
30.Berk, J. 2008. Effect of different kinds of litter on severity and prevalence of pododermatitis in male broilers. In
Proc. XXIII World’s Poult. Congr., Brisbane, Australia [CDROM]. 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 of bark-based poultry litter as a substrate component
in nursery crop production. Proc. Southern Nursery Assoc.
Res. Conf. 54:121–123.