Management Tools to Reduce
Footpad Dermatitis in Broilers
By: Dr. Ingrid de Jong & Ing. Jan van Harn
Copyright 2012, Aviagen, all rights reserved.

Management Tools to Reduce
Footpad Dermatitis in Broilers
By: Dr. Ingrid de Jong & Ing. Jan van Harn

Dr. Ingrid de Jong is the Senior Researcher in Poultry Welfare at Wageningen
University (Livestock Research) in Lelystad, The Netherlands. She joined the
University in 2002 as a Scientific Researcher and has served as the project leader
and researcher of various projects in poultry and rabbit welfare. Recent research
topics include: management to prevent mutilations in laying hens and broiler
breeders; footpad lesions in broiler chickens; further development of Welfare
Quality broiler welfare monitor; development of group housing systems for
rabbit does. Dr. de Jong is a member of EFSA scientific panels on broiler andbreeder welfare (2010) and animal-based measures in broilers (2012).

Jan van Harn, BSc, is a Poultry Nutrition Researcher and Account Manager for
Broilers in the Animal Sciences Group of Wageningen University (LivestockResearch) in Lelystad, The Netherlands. Since joining the Animal Science
Group in 2003, he has led management trials with broilers on various subjects
including, comparisons of lighting schedules and/or temperature scheme’s, andthe reduction of footpad dermatitis through management. He has also conducted
several environmental trials to reduce ammonia and fine dust emissions frompoultry housing systems.

Ingrid  de  Jong  &  Jan  van  Harn
Wageningen  Livestock  Research  Wageningen  University  and  Research  Centre
PO  Box  65
8200  AB  Lelystad
The  Netherlands.

Summary
Footpad  dermatitis  (FPD)  is  receiving  increasing  attention  in  the  broiler  industry.  
Footpad  dermatitis  affects  animal  welfare  and  farmer  income,  and  in  the  future  it  is  likely  to  have  increasing  importance  in  terms  of  legislation.  Wet  and  sticky  litter  is  the  major  cause  of  footpad  dermatitis.  So,  by  maintaining  a  good  litter  quality,  broiler  producers  can  reduce  losses  and  improve  bird  welfare.  This  document  gives  broiler  producers  management  tools  to  help  reduce  footpad  dermatitis  in  broilers.

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Footpad  dermatitis  (FPD)  is  commonly  seen  in  the  broiler  industry.  In  Sweden,  before  the  welfare  monitoring  programme  started,  32%  of  all  broilers  were  considered  to  have  mild,  and  6%  of  all  broilers  severe,  footpad  lesions  (Ekstrand  et  al,  1997).  Before  Denmark  began  monitoring  FPD,  just  below  40%  of  all  broilers  were  considered  to  have  severe  footpad  lesions  in  the  summer.  However,  the  incidence  of  FPD  in  Denmark  has  decreased  sharply  since  the  mandatory  monitoring  of  FPD  was  introduced  in  2002  (see  Figure  1).  In  The  Netherlands,  De  Jong  et  al  (2011)  showed  that  38.4%  of  broilers  had  severe  lesions  ZKLOHRIEURLOHUVGLVSOD\HGPLOGOHVLRQV7KHVDPHVWXG\DOVRVKRZHGDFOHDUVHDVRQDOLQÀXHQFH
on  the  incidence  of  FPD.  Broilers  placed  between  June  and  August  had  lower  levels  of  severe  FPD  and  a  lower  FPD  score  than  broilers  placed  in  March  and  December.  A  similar  seasonal  pattern  in  FPD  has  been  seen  in  Denmark  and  Sweden.
Figure  1:  Variation  in  footpad  scores  in  Denmark  between  2002  (year  monitoring  programme  started)  and  2010.  The  red  line  (‘Lovkrav’)  indicates  the  Danish  footpad  score  limit.  6RXUFH3HWHUVHQ9)/
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Changes  in  footpad  scores  from  2002  to  2010

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Broilers  spend  their  whole  life  in  close  contact  with  some  type  of  litter  material  and  are  also  in  regular  contact  with  droppings  which  form  a  part  of  the  litter  surface.  If  litter  conditions  are  suboptimal  there  is  considerable  risk  that  birds  will  develop  contact  dermatitis  on  their  feet,  hock  and/or  breast.  FPD,  also  called  pododermatitis,  foot  burn  or  footpad  lesions,  is  a  contact  dermatitis  of  the  plantar  surface  of  the  birds’  feet.  FPD  starts  as  an  erosion  of  the  skin  on  the  foot.  This  can  initially  appear  as  a  dirty  mark,  but  once  the  skin  is  broken,  painful  ulcers  may  develop  (Figure  2).  Broilers  with  severe  lesions  will  experience  pain  and  therefore,  move,  eat  and  drink  less.  Broilers  with  severe  lesions  also  often  have  other  types  of  contact  dermatitis  such  as  breast  blisters  or  hock  burns.  In  addition  to  causing  pain,  the  lesions  can  be  a  gateway  for  bacteria,  which  can  cause  impaired  product  quality  (increased  downgrades  and  rejections  at  the  processing  plant)  and  secondary  infections  (Staphylococci  spp.  and  E.  coli).  Flocks  with  a  high  LQFLGHQFHRI)3'ZLOOKDYHDORZHUJURZWKUDWHLQFUHDVHGGRZQJUDGHVDQGUHGXFHGSUR¿WDELOLW\Figure  2:  Left:  no  footpad  lesion;;  Right:  severe  footpad  lesion.  

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In  Asia,  chicken  feet  are  a  valuable  product  for  human  consumption.  The  increased  demand  from  the  Asian  markets  has  made  broiler  feet  an  important  export  commodity  for  the  EU  broiler  industry.  However,  RQO\IHHWZLWKQROHVLRQVFDQEHH[SRUWHG7KHHFRQRPLFDQGZHOIDUHVLJQL¿FDQFHRI)3'IRUWKHEURLOHU
industry  is  clear.    
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E\DGMXVWLQJÀRFNPDQDJHPHQWFPD  AS  AN  INDICATOR  FOR  ANIMAL  WELFARE
In  Europe,  the  welfare  of  broilers  is  receiving  increasing  attention.    This  is  clearly  illustrated  by  the  European  Council  Broiler  Directive  which  lays  down  minimum  standards  for  the  protection  of  chickens  kept  for  meat  production  (Council  Directive  2007/43/European  Council,  2007).  The  Directive  restricts  maximum  stocking  density,  but  also  prescribes  requirements  on  housing  conditions  (e.g.  light  intensity  and  duration,  air  quality)  and  stockmanship.  
Individual  countries  may  choose  to  include  in  the  Broiler  Directive  additional  welfare  measures  (other  than  mortality)  in  their  national  legislation.  FPD  could  be  (and  is  increasingly  likely  to  be)  one  such  additional  measure.  In  Sweden  and  Denmark  FPD  has  been  used  as  an  indicator  of  the  welfare  of  broiler  ÀRFNVIRUVHYHUDO\HDUVQRZ,WLVH[SHFWHGWKDWLQWKHQH[WFRXSOHRI\HDUVRWKHU(XURSHDQFRXQWULHVZLOO
also  choose  to  include  FPD  as  an  additional  measure  of  broiler  welfare  in  their  national  legislation.    
MEASURING  FOOTPAD  DERMATITIS
A  number  of  scoring  systems  have  been  developed  to  assess  FPD  incidence  and  severity  within  LQGLYLGXDOEURLOHUÀRFNV7KH6ZHGLVKV\VWHP %HUJ LVWKHJHQHUDOO\DFFHSWHG)3'VFRULQJV\VWHP
used  within  Europe.  This  system  is  a  three  tier  scoring  system.

SCORE
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DESCRIPTION
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of  the  footpad,  mild  hyperkeratosis  (thickening  of  the  outer  layer  of  the  skin)  or  healed  lesion.

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hyperkeratosis.

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Severe  lesion;;  epidermis  is  affected,  ulcers  or  scabs,  signs  of  haemorrhages  or  swollen  footpads.

Compared  to  more  detailed  scoring  methods,  the  Swedish  system  has  the  advantage  of  being  easy  to  learn  and  thus  is  practical.  Moreover,  the  Swedish  system  distinguishes  between  severe  lesions  that  are  painful  and  have  a  negative  effect  on  the  welfare  of  the  chicken,  and  mild  lesions,  which  it  is  generally  believed  are  probably  not  painful  but  are  a  risk  for  reduced  welfare  (Ekstrand  et  al,  1998,  Haslam  et  al,   $PRGL¿HGSKRWRJXLGHIRUEURLOHUIRRWKHDOWKFODVVL¿FDWLRQEDVHGRQWKH6ZHGLVKVFRULQJPHWKRG
has  been  developed  by  Wageningen  UR  Livestock  Research  and  is  located  at  the  end  of  this  document.  
You  may  also  contact  your  local  Aviagen  Technical  Services  Manager  for  more  information.
Footpad  lesions  can  be  assessed  at  the  slaughterhouse  (visually  or  using  a  camera)  or  at  the  broiler  farm  (visual  assessment).  Assessing  FPD  at  the  slaughterhouse  has  several  advantages:
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Assessment  takes  place  on  clean  footpads  (most  litter  and  manure  is  removed  in  the  scalding  tank).
Assessment  does  not  cause  stress  to  the  birds  as  it  takes  place  after  killing.
Lighting  is  better  in  the  slaughterhouse  than  in  a  commercial  broiler  house  making  assessment  easier  and  potentially  more  accurate.

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100%  x  [(0  x  the  total  number  of  specimens  with  score  0)  +    (0.5  x  the  total  number  of  specimens  with  score  1)  +  (2  x  the  total  number  of  specimens  with  score  2)]Total  number  of  scored  specimens  7KHÀRFN)36UDQJHVIURP DOOVSHFLPHQVKDYLQJQROHVLRQV WR DOOVSHFLPHQVKDYLQJVFRUH ,Q
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CAUSES  OF  FOOTPAD  DERMATITISThe  prevalence  of  FPD  is  strongly  linked  to  litter  quality;;  wet,  sticky  and  caked  litter  increases  the  prevalence  of  FPD.  Footpad  lesions  are  sometimes  referred  to  as  ammonia  burns  but  this  is  not  completely  correct.  Several  studies  have  shown  that  litter  moisture  alone  can  cause  or  induce  FPD  (Mayne  et  al,  2007;;  Youssef  et  al.,  2008).  The  presence  of  ammonia  or  other  chemical  substances  in  the  litter  may  play  a  role  in  the  further  development  of  FPD  but  does  not  appear  to  cause  it  directly.  
FPD  increases  in  severity  as  litter  moisture  increases.  The  best  way  to  prevent  FPD  is  to  keep  the  litter  dry  and  friable,  especially  during  the  brooding  period  when  the  birds  appear  to  be  more  susceptible  to  OHVLRQGHYHORSPHQW/LWWHUTXDOLW\LVLQÀXHQFHGE\DQXPEHURIIDFWRUV
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Litter  management  (litter  material  and  litter  depth).
Light:  distribution  of  light,  light  colour,  and  lighting  programme.
Water  supply  and  water  management.
Ventilation  and  heating.
Feed.
Stocking  density.
Breed  &  disease  may  also  play  a  role  but  these  factors  will  not  be  discussed  here.

LITTER  MANAGEMENT
Litter  Material
In  Northern  European  countries  wood  shavings  and  chopped  (to  increase  water  absorption  capacity)  wheat  straw  are  the  most  commonly  used  litter  materials  for  broilers.  But  other  materials  such  as  peat,  lignocellulose,  rapeseed  straw,  and  maize  silage  are  also  used.  
German  research  found  that  compared  with  wood  shavings  and  chopped  straw  the  use  of  lignocellulose  (Pelletino®  Strohstreugranulat  G)  reduced  FPD  (Berk,  2009).  This  reduction  in  FPD  is  thought  to  be  due  to  the  higher  water  binding  capacity  and  the  faster  water  release  of  lignocellulose.  
De  Baere  and  Zoons  (2004a)  compared  chopped  wheat  straw  and  wood  shavings  as  litter  material  for  broilers.  Broiler  performance  was  not  found  to  differ  between  the  two  litter  materials,  but  there  was  less  FPD  on  wood  shavings  than  on  chopped  straw  (see  Figure  3).  In  contrast,  Van  Harn  et  al  (2009)  did  not  ¿QGDGLIIHUHQFHLQVHYHULW\RI)3'EHWZHHQWKHWZROLWWHUPDWHULDOV  3

Figure  3:    Comparison  of  wood  shavings  and  chopped  wheat  straw  on  the  severity  of  FPD  (Score  0  =  no  lesion;;  Score  1  =  mild  lesions;;  Score  2  =  moderate  lesions  and  Score  3  =  severe  lesions).  Incidence  of  FPD  lower  and  less  severe  on  wood  shavings  (P<0.001).    6RXUFHGH%DHUHDQG=RRQVD
6WURRLVHOPDWHULDDOLQSOXLPYHHVWDOOHQ3OXLPYHHQU

Straw
Score  0Score  1Score  2Score  3

Wood  shavings

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In  Scandinavian  countries,  peat  is  often  used  as  a  litter  material  for  broilers,  especially  during  the  winter  months  (a  combination  of  wood  shavings  and  peat  may  also  be  used).  Comparisons  of  wheat  straw,  wood  shavings  and  peat  have  demonstrated  that  most  severe  FPD  occurs  on  (chopped)  wheat  straw,  followed  by  wood  shavings,  with  FPD  being  least  severe  on  peat.  
From  small  and  large  scale  experiments  in  Denmark,  the  following  rules  of  thumb  can  be  given:  1.  Wood  shavings:  gives  a  footpad  score  that  is  20  points  lower  than  straw.  
2.  Peat:  gives  a  footpad  score  that  is  20  –  40  points  lower  than  straw.  
Belgian  research  has  also  shown  that  the  use  of  peat  as  a  litter  material  for  broilers  reduces  the  severity  of  FPD  (De  Baere,  2006).
In  conclusion,  to  lower  the  risk  of  FPD,  studies  suggest  that  the  use  of  peat  or  a  mixture  of  peat  and  wood  shavings  (50/50)  as  a  litter  material  instead  of  wood  shavings  or  chopped  wheat  straw  is  preferable,  especially  during  the  winter  months.  If  peat  is  not  available,  or  is  too  expensive,  wood  shavings  are  better  WKDQZKHDWVWUDZ7KHXVHRIOLJQRFHOOXORVHDVOLWWHUPDWHULDOFRXOGDOVREHFRQVLGHUHGEXW¿HOGLQIRUPDWLRQon  the  use  of  this  product  is  not  yet  available.
  Bedding  Amount  /  Litter  Depth
7KHLQÀXHQFHRIOLWWHUPDWHULDOGHSWKRQ)3'LVQRWDOZD\VFOHDU5HVHDUFKHUVIRXQGQRGLIIHUHQFHLQ)3'
incidence  between  using  1.0  kg  or  1.5  kg/m2  wood  shavings  or  chopped  wheat  straw.  However,  using  more  than  1.5  kg/m2  of  chopped  wheat  straw  was  found  by  De  Baere  and  Zoons  (2004b)  to  increase  the  severity  of  FPD  (Figure  4).  

4Figure  4:    Effect  of  bedding  depth  (chopped  wheat  straw:  1.5  vs.  2.0  kg/m2)    on  the  severity  of  FPD  (Score  0  =  no  lesion;;  Score  1  =  mild  lesions;;  Score  2  =  moderate  lesions  and  Score  3  =  severe  lesions).  
Providing  more  than  1.5  kg/m2RIFKRSSHGZKHDWVWUDZVLJQL¿FDQWO\LQFUHDVHGWKHLQFLGHQFHDQGVHYHULW\of  FPD  (P<  0.001).    6RXUFH'H%DHUHDQG=RRQVE6WURRLVHOELMYOHHVNXLNHQVKRHYHHOKHLG
KRXWNUXOOHQHQVWUR3OXLPYHHQU

2.0  kg/m²
Score  0Score  1Score  2Score  31.5  kg/m²

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80%

100%

In  contrast,  a  study  by  Van  Harn  et  al  (2009)  comparing  the  use  of  1.0  and  2.0  kg/m2  wood  shavings  and  1.25  and  2.5  kg/m2FKRSSHGZKHDWVWUDZFRQFOXGHGWKDWDPRXQWRIOLWWHUPDWHULDOKDGQRLQÀXHQFHRQ
broiler  performance  or  incidence  of  FPD.
However,  for  control  of  FPD,  using  a  thinner  layer  of  litter  material  (0.5-­1.0  kg/m2 PD\EHEHQH¿FLDODV
a  rough  guide  1  kg/m2  equates  to  a  depth  of  1  cm  for  wood  shavings,  for  chopped  wheat  straw  a  depth  of  1  cm  will  be  achieved  with  1.5  kg/m2.    Chickens  are  more  likely  to  peck,  scratch  and  turn  the  litter  if  it  is  not  too  deep;;  working  of  the  litter  in  this  way  increases  aeration  and  helps  to  keep  the  litter  drier.  A  thin  layer  of  litter  may  also  be  able  to  be  kept  more  dry  and  friable  by  the  air  stream  from  the  fans  than  a  thick  OD\HURIOLWWHU,IDWKLQQHUOD\HURIOLWWHUPDWHULDOLVXVHGSUHZDUPLQJRIWKHÀRRUSULRUWRÀRFNSODFHPHQW
is  essential.  Floor  temperature  prior  to  placement  should  be  at  least  30°C.  This  will  prevent  condensation  IURPEXLOGLQJXSRQWKHFRQFUHWHÀRRUZKLFKZLOOKHOSWRPDLQWDLQOLWWHUTXDOLW\7KHOLWWHUPDWHULDOVKRXOG
QRWEHVSUHDGRXWXQWLODIWHUWKHWDUJHWÀRRUWHPSHUDWXUHKDVEHHQUHDFKHG6SUHDGLQJWKHOLWWHUSULRUWR
SUHZDUPLQJWKHKRXVHPHDQVWKHFRQFUHWHÀRRUZLOOZDUPXSPRUHVORZO\DQGWKHULVNRIFRQGHQVDWLRQ
forming  will  be  increased.

1RWH,IWKHÀRRULVQRWZHOOLQVXODWHGRUQRWSUHKHDWHGLWLVEHWWHUWRXVHDWKLFNHUOD\HURIEHGGLQJDRINKER  AND  WATER  MANAGEMENT  7KHW\SHRIGULQNLQJV\VWHPXVHGKDVDFOHDULQÀXHQFHRQWKHSUHYDOHQFHRI)3'+RZHYHUSHUIRUPDQFH
is  not  always  optimised  with  drinking  systems  that  result  in  a  low  incidence  of  FPD  (Petersen,  2004  –  Table  1).  

5Table  1:  Effect  of  drinking  system  type  on  footpad  score  (FPS).  6RXUFH3HWHUVHQ %RNVIRUV¡JQU
Corti  110

Corti  65

Val

LifeLine

Type  of  drinker

Drip  cup

NippleNippleCup

Replicates  n

3

3

3

3

P-­Value-­

Feed  intake  d  0-­38  (g)

3684

3604

3667

3759

0.15

Water  intake  d  0-­38  (ml)a6829  

c5854  b6524  

ab6714  

<0.01

Water  /  feed  d  0-­21

1.90  a1.64  c1.84  b1.78  d0.02

Water  /  feed  d  22-­38

a1.83  c1.62  

b1.75  

ab1.79  

<0.01

Live  weight  d  38  (g)ac2155  

2057  

ab2105  

2200  

<0.01

FCR  d  0-­38

1.71

1.75

1.74

1.71

0.11

Footpad  score

50  

13  

38  

68  

0.02

a

b

cb

ab

c

a

,IVXSHUVFULSWVGLIIHU3
It  is  well  known  that  nipple  drinkers  reduce  water  spillage  compared  to  drinking  systems  with  drinking  cups;;  this  decreases  the  risk  of  wet  litter  and  therefore  FPD.  The  effect  of  drinking  systems  on  the  incidence  of  )3'KDVEHHQFOHDUO\GHPRQVWUDWHGE\D¿HOGVWXG\FRPSOHWHGLQ6ZHGHQ (NVWUDQG 7KHXVHRI
nipple  drinkers  with  drip  cups  (Figure  5)  can  improve  things  even  further.    
  Figure  5:  Nipple  drinkers  with  drip  cups  reduce  water  spillage.

3KRWR:DJHQLQJHQ85
Comparison  tests  of  drinking  systems  in  Danish  research  (Jørgensen,  2011a;;  Jørgensen,  2011b)  showed  that  the  use  of  nipple  drinkers  with  drip  cups  not  only  reduces  the  severity  of  FPD,  but  also  improves  broiler  performance  compared  to  the  use  of  nipples  without  drip  cups.    Dutch  research  (Van  Harn  et  al,  2009)  VXSSRUWVWKHVH¿QGLQJV Table  2).

6

Table  2:  Effect  of  drip  cup  on  performance  results,  dry  matter  content  of  the  litter,  and  footpad  lesions  (Van  Harn  et  al,  2009).
Parameter*

Drinking  Nipple

Drip  Cup

Body  weight  (g)a2047  

2093  bBody  weight  gain  (g/b/d)57.4  a58.7  bMortality  (%)

2.5

2.6

FCR

b

1.603  

1.595  aFeed  intake  (g)3219  a3276  b

Water  intake  (ml)

5814

5831

Water  /  feed  ratiob1.81  

1.78  aEPEF

349  a358  bDry  matter  litter  (%)

48.7  a52.8  b1R 6FRUH

040LOG 6FRUH

a

4  

18  b

6HYHUH 6FRUH

95

78

Footpad  lesions  (%),IVXSHUVFULSWVGLIIHU3
Drinking  line  height  should  be  appropriate  for  bird  height,  not  bird  age.  Many  producers  have  the  drinker  OLQHVWRRORZEHFDXVHRIFRQFHUQVWKDWWKHELUGVZRQ¶WEHDEOHWR¿QGZDWHU7KHGULQNLQJOLQHLVDWWKH
optimal  height  when  the  birds  (when  standing)  have  to  reach,  not  stretch,  for  the  nipple.  Water  will  then  ÀRZIURPWKHQLSSOHVWUDLJKWLQWRWKHELUGV¶EHDN,IDELUGKDVWRWXUQLWVKHDGVLGHZD\VWRDFWLYDWHWKH
nipple  (i.e.  the  nipple  is  too  low),  some  water  will  fall  on  to  the  litter  resulting  in  wet  litter  and  a  higher  risk  of  FPD.  Older  broilers,  especially,  will  also  play  with  the  water  if  drinking  lines  hang  too  low.  To  minimise  problems  with  wet  litter,  drinking  line  height  should  be  adjusted  daily.
It  is  important  that  the  drinking  system  is  well  maintained  and  regularly  checked  for  leakage.  If  nipples  DUHOHDNLQJRUEORFNHGWKH\PXVWEHUHSODFHG'ULQNLQJV\VWHPVVKRXOGEHÀXVKHGZLWKIUHVKZDWHU
DQGFOHDQHG GLVLQIHFWHG EHIRUHHDFKQHZÀRFN6WRUDJHWDQNVVKRXOGEHFOHDQHGUHJXODUO\DQGZDWHU
analysed  annually;;  an  analysis  for  bacterial  contamination  and  a  chemical  analysis  (for  example,  for  FDOFLXPVDOWVVDOLQLW\DQGQLWUDWHV VKRXOGEHFRPSOHWHG'ULQNLQJV\VWHPVVKRXOGDOVREHÀXVKHGZLWK
fresh  water  after  any  product  (e.g.  medication  or  vitamins)  is  run  through  the  line.  These  practices  will  avoid  the  build  up  of  contaminants  or  blockages  in  the  system.  It  is  good  practice  to  replace  the  entire  GULQNLQJV\VWHPHYHU\\HDUV1HZGULQNLQJOLQHVPXVWEHÀXVKHGEHIRUH¿UVWXVHWRUHPRYHDQ\debris  that  may  still  be  present  in  the  line  (debris  in  the  line  will  increase  the  risk  of  leakage).  
Water  pressure  must  meet  the  guidelines  set  out  by  the  drinker  system  manufacturer.  If  water  pressure  is  too  low,  birds  will  not  be  able  to  consume  enough  water,  and  bird  welfare,  feed  intake  and  growth  will  be  affected.  If  water  pressure  is  too  high,  water  leakage  will  occur,  leading  to  wet  litter  and  an  increased  risk  of  FPD  (Figure  6).  

    

7

Figure  6:  Effect  of  water  pressure  on  footpad  score  (6RXUFH3HWHUVHQ %RNVIRUV¡JQU ).    
Normal  water  pressure  was  10,  17  and  20  cm  of  water  column,  low  water  pressure  was  8,  12  and  15  cm  of  water  column,  and  high  water  pressure  was  20,  25  and  30  cm  of  water  column  at  0-­14,  14-­28  and  28-­
38  days,  respectively.  Water  yield  was  19,  49  and  59  ml/min  for  normal  water  pressure,  18,  39  and  52  ml/min  for  low  water  pressure  and  76,  80  and  85  ml/min  for  high  water  pressure  at  0-­14,  14-­28  and  28-­38  days  of  age,  respectively.

120

Footpad  score

100
80
Normal

60

Low
40

High

20
0
7

14

21

38

Age  in  days
$V\RXQJEURLOHUVDUHPRUHVXVFHSWLEOHWR)3'DFKLHYLQJWKHFRUUHFWZDWHUSUHVVXUHGXULQJWKH¿UVWWZR
ZHHNVDIWHUSODFHPHQWLVHVSHFLDOO\LPSRUWDQW$WWKLVWLPHZDWHUSUHVVXUHDQGWKHUHIRUHÀRZVKRXOGbe  low.  Thereafter,  water  pressure  can  be  adjusted  rapidly.  Lowering  water  pressure  may  help  to  reduce  the  severity  of  FPD  by  reducing  litter  moisture  content  (Van  Harn  et  al,  2009).  However,  any  reduction  in  water  pressure  must  be  managed  with  extreme  care,  if  water  pressure  becomes  too  low,  broiler  performance  and  welfare  will  be  negatively  affected.  
Optimal  water  supply  is  important  for  the  birds  to  grow  well  and  for  bird  welfare.  Broilers  should  have  unlimited  access  to  clean,  fresh,  good  quality  drinking  water  at  all  times.  However,  when  water  intake  is  naturally  low,  for  example  during  the  dark  period  when  birds  are  inactive,  control  of  water  supply  may  help  to  reduce  unnecessary  water  leakage.  Any  such  control  of  water  must  be  managed  with  care;;  there  must  be  no  restriction  in  the  amount  of  water  needed  for  birds  to  grow,  and  a  balance  must  be  found  between  growth,  welfare  and  potential  FPD  risk.    
Water  should  have  a  low  bacterial  count  and  be  free  from  E.  coli  and  Pseudomonas  spp.  The  presence  of  any  of  these  organisms  in  the  water  will  challenge  the  gut  and  increase  the  risk  of  enteritis,  a  common  FRQVHTXHQFHRIZKLFKLVZHWOLWWHU5HJXODUGLVLQIHFWLRQDQGÀXVKLQJRUFOHDQLQJRIWKHGULQNLQJV\VWHPZLOOSUHYHQWWKHEXLOGXSRIELR¿OPV ZKLFKFDQERWKFRQWDPLQDWHDQGEORFNWKHGULQNLQJV\VWHP 5HFHQWVWXGLHVLQ7KH1HWKHUODQGV 9DQ+DUQDQG'H-RQJD IRXQGHYLGHQFHWKDWWKHXVHRIDQDFLGL¿HGZDWHUDGGLWLYH ZKLFKUHPRYHVDQGSUHYHQWVWKHEXLOGXSRIELR¿OP PD\KHOSWRUHGXFHWKHVHYHULW\RI
FPD.  However,  acidifying  water  was  also  found  to  result  in  a  lower  growth  rate.  Similar  results  were  found  when  water  restriction  (Table  3)  was  implemented.  

8Table  3:  Effect  of  acidifying  drinking  water  and  water  restriction  on  performance  results,  dry  matter  content  of  the  litter,  and  footpad  lesions  (Van  Harn  and  De  Jong,  2012a).
Parameter*

Control$FLGL¿HG:DWHU

Water  Intake  Controlled  to  WKH6DPH/HYHODV$FLGL¿HG
Water  Intake

Body  weight  (g)2106  b1961  a1974  aBody  weight  gain  (g/b/d)

58.9  b54.8  a55.2  aMortality  (%)

1.7

2.0

2.3

FCR

1.584

1.597

1.592

Feed  intake  (g)

3269

  a

3063

3074  aWater  intake  (ml)5964  b5327  a5242  aWater  /  feed  ratiob1.82  

  a

1.74

1.71  aEPEF

366  b336  a339  aDry  matter  litter  (%)

60.7  a65.6  b65.2  b  b

Footpad  lesions  (%)
1R 6FRUH

5.5

35.0

38.5

0LOG 6FRUH

28.0  a50.5  b47.5  b6HYHUH 6FRUH

66.5

14.5

14.0

*If  superscripts  differ  P<0.05.
LIGHTING  AND  DISTRIBUTION  OF  LIGHT
Light  Duration
The  European  Council  Broiler  Directive  stipulates  the  following  guidelines  regarding  light  intensity  and  duration:
Within  7  days  from  the  time  when  the  chickens  are  placed  in  the  building  and  until  3  days  prior  to  the  foreseen  time  of  slaughter,  lighting  must  follow  a  24-­hour  rhythm  and  include  periods  of  darkness  lasting  at  least  6  hours  in  total,  with  at  least  one  uninterrupted  period  of  darkness  of  at  least  4  hours,  excluding  dimming  periods.
All  buildings  must  have  lighting  with  an  intensity  of  at  least  20  lux  during  the  lighting  periods,  measured  at  bird  eye  level  and  illuminating  at  least  80  %  of  the  useable  area.  A  temporary  reduction  in  the  lighting  level  may  be  allowed  when  necessary  following  veterinary  advice.

Studies  in  The  Netherlands  and  Belgium  have  found  evidence  that  intermittent  light  schedules  may  be  EHQH¿FLDOIRUUHGXFLQJWKHRFFXUUHQFHRI)3' 'H%DHUH9DQ+DUQ 'XULQJWKHOLJKWSHULRG
birds  are  more  active  and  scratch  more  which  keeps  the  litter  more  friable.  An  intermittent  light  schedule  has  also  been  shown  to  improve  feed  conversion  ratio  (FCR).  This  all  leads  to  dryer  and  more  friable  litter,  and  a  potential  decrease  in  FPD  (Table  4).  

9Table  4:  Day/night  versus  intermittent  light:  effect  of  light  scheme  on  performance  results,  dry  matter  content  of  the  litter,  and  footpad  lesions  (Van  Harn,  2009).  
Parameter*

18L:6D1

Intermittent2

Body  weight  (g)2029  a2061  bBody  weight  gain  (g/b/d)

58.5  a59.4  bMortality  (%)

3.5

3.7

FCR

1.572

1.566

Feed  intake  (g)3125  (a)3164  (b)Water  intake  (ml)

5243

5233

Water  /  feed  ratio

  b

1.68

1.65  aEPEF

359  a366  bDry  matter  litter  (%)

58.6  a61.2  b1R 6FRUH

50.7

61.4

0LOG 6FRUH

42.3  

35.8  b6HYHUH 6FRUH

7.0

2.8

Footpad  lesions  (%)
a

18L:6D;;  24L:4D:3L:1D:3L:1D:3L:1D:3L:1D*If  superscripts  differ  P<0.05.

1Light  Distribution
To  maintain  good  litter  quality  an  even  distribution  of  light  throughout  the  broiler  house  is  crucial.  Broilers  prefer  to  rest  in  areas  with  a  low  light  intensity.  If  light  intensity  in  the  house  is  uniform,  the  distribution  of  the  birds  in  the  house,  and  therefore  the  litter  quality,  will  be  more  uniform.  If  it  is  not  possible  to  achieve  uniform  light  distribution,  placing  tape  or  a  metal  plate  with  small  holes  underneath  the  lamp  will  help  to  improve  uniformity  of  light  distribution.  Light  distribution  is  better  with  incandescent  lights  (light  bulbs)  than  ZLWKÀXRUHVFHQWOLJKWLQJ9HUWLFDOPRXQWLQJRIÀXRUHVFHQWOLJKWLQJZLOODOVRLPSURYHOLJKWGLVWULEXWLRQ
7KHXVHRIGLPPDEOHÀXRUHVFHQWOLJKWLQJKDVEHHQVKRZQWRGHFUHDVHWKHIULDELOLW\RIWKHOLWWHUSDUWLFXODUO\ZKHQWKHÀXRUHVFHQWOLJKWVDUHSRVLWLRQHGQHDUWRWKHÀRRU OHVVWKDQP 7KLVFDQOHDGWREHKDYLRXUDOFKDQJHVSUREDEO\GXHWRWKHOLJKWVÀLFNHULQJZKHQGLPPHGZKLFKUHVXOWVLQOLWWHUGHSWKXQGHUWKHOLJKWV
being  reduced.  If  droppings  are  passed  onto  minimal  amounts  of  litter  it  will  quickly  become  capped.  If  litter  levels  do  become  depleted  under  the  lights,  the  litter  should  be  moved  back  or  replaced  as  soon  as  possible.
Light  Colour  and  Light  Intensity
There  is  little  information  available  about  the  effect  of  light  colour  on  the  severity  of  FPD.  However,  studies  in  Belgium  (De  Baere  and  Zoons,  2004c)  have  found  evidence  that  the  use  of  light  bulbs  (incandescent  OLJKWLQJ LQVWHDGRI7/ ÀXRUHVFHQWOLJKWLQJ GHFUHDVHVWKHVHYHULW\RIIRRWSDGOHVLRQVLQEURLOHUÀRFNV
(Figure  7 $Q\SRWHQWLDOEHQH¿WPXVWEHEDODQFHGDJDLQVWWKHLQFUHDVHGHQHUJ\XVHRIOLJKWEXOEV
compared  to  TL  and  sodium  light.  Research  in  The  Netherlands  in  which  TL  light  was  compared  with  VRGLXPKLJKSUHVVXUHOLJKWDQGJUHHQEOXH3/OLJKWLQJLQGLFDWHGWKDWOLJKWFRORXUKDVDOLPLWHGLQÀXHQFH
on  FPD  (Rodenburg  et  al,  2004),  although  there  was  a  tendency  for  FPD  to  be  lower  with  green/blue  light.  The  European  Council  Broiler  Directive  requires  a  minimum  light  intensity  of  20  lux  at  birds’  eye  level  during  the  entire  growing  period.  It  is  questionable  whether  the  European  Council  Broiler  Directive  prescribed  light  intensity  of  20  lux  can  be  achieved  with  green/blue  light.

10

Figure  7:(IIHFWRIOLJKWLQJV\VWHP ÀXRUHVFHQWYVLQFDQGHVFHQWOLJKWLQWHQVLW\OX[ RQWKHVHYHULW\of  FPD  (Score  0  =  no  lesion;;  Score  1  =  mild  lesions;;  Score  2  =  moderate  lesions  and  Score  3  =  severe  lesions).  Incandescent  lighting  reduces  the  incidence  and  severity  of  FPD  (P  =  0.01).    6RXUFHGH%DHUH
DQG=RRQVF/LFKWVWHUNWHHQOLFKWNOHXUELMYOHHVNXLNHQV3OXLPYHHQU

Fluorescent  lighƟng  Score  0Score  1Score  2Score  3

Incandescent  lighƟng

0%

20%

40%

60%

80%

100%

Research  completed  in  The  Netherlands  and  Belgium  before  the  European  Council  Broiler  Directive  was  implemented  (at  a  time  when  many  broilers  were  kept  at  light  intensities  lower  than  20  lux)  indicated  that  WKHXVHRIOLJKWLQWHQVLWLHVEHORZOX[ZDVQRWEHQH¿FLDOWR)3' 'H%DHUHDQG=RRQVF9DQ+DUQ
2009).  
ENVIRONMENT
Ventilation  and  Temperature  Control
The  aim  of  ventilation  is  to  supply  birds  with  fresh  air  and  to  remove  excess  heat,  and  (importantly  for  FPD)  moisture,  harmful  gasses,  such  as  ammonia  and  carbon  dioxide,  dust,  and  airborne  organisms  from  the  house.    In  practice,  ventilation  is  a  compromise  between  maintaining  the  in-­house  temperature  DQGVXSSO\LQJVXI¿FLHQWIUHVKDLUWRWKHELUGV,WLVLPSRUWDQWWKDWVXI¿FLHQWYHQWLODWLRQLVSURYLGHGIURP
placement.  Young  broilers  are  more  susceptible  to  the  development  of  FPD,  therefore  it  is  recommended  WRFLUFXODWHWKHDLULQWKHKRXVHXVLQJLQWHUQDOFLUFXODWLRQIDQVGXULQJWKH¿UVWFRXSOHRIGD\VDIWHU
placement,  while  applying  appropriate  minimum  ventilation.  To  save  on  energy  costs,  particularly  during  winter,  broiler  producers  often  minimise  ventilation  rate.    However,  reducing  ventilation  rates  too  much,  even  during  periods  of  cold  weather,  will  increase  the  relative  humidity  (RH)  in  the  house,  which  will  increase  the  risk  of  wet  litter  and  footpad  lesions.  It  is  important  that  some  minimum  level  of  ventilation  is  given  at  all  times.
As  broilers  grow,  environmental  temperature  within  the  house  must  be  reduced.    Recent  research  from  Wageningen  UR,  found  evidence  that  a  more  rapid  decline  temperature  schedule  (Table  5)  may  increase  the  severity  of  FPD  (Table  6).  

11Table  5:  Temperature  schedules  used  to  determine  the  effect  of  rate  of  temperature  reduction  on  FPD.    
Both  temperature  schedules  tested  are  higher  than  Aviagen’s  current  published  recommendations  (see  Ross  Broiler  Management  Manual  for  further  details).
Age  (days)

Control  (rapid  decline)  Temperature  Scheme

  Slower  Decline  Temperature  Scheme

-­5

-­-­

25

-­4

-­-­

25

-­3

-­-­

30

-­2

28

30

-­1

30

33

0

33

33

1

33

33

7

28

30

14

25

28

21

22

25

28

21

22

35  

20

20

42  

19

19

Table  6:  Effect  of  temperature  scheme  (Table  5)  on  performance  results,  dry  matter  content,  and  footpad  lesions  (Van  Harn  and  de  Jong,  2012b).
Parameter*
Body  weight  (g)Control  Temperature  Decline2108

Slow  Temperature              Decline2108

Body  weight  gain  (g/b/d)

59.0

59.0

Mortality  (%)

3.6  (b)3.0  (a)FCR

1.566  b1.536  aFeed  intake  (g)3236  b3171  aWater  intake  (ml)

5678

5687

Water  /  feed  ratioa1.75  

1.79  b

EPEF

364  a373  bDry  matter  litter  (%)

65.5  a67.0  b1R 6FRUH

69.1

86.2

0LOG 6FRUH

23.5  

11.2  b6HYHUH 6FRUH

7.4

2.6

Footpad  lesions  (%)
a*If  superscripts  differ  P<0.05.

12The  type  of  heat  source  used  can  also  affect  the  occurrence  of  footpad  lesions.  Since  the  start  of  the  footpad  monitoring  programme  in  Denmark,  the  number  of  broiler  houses  with  open  combustion  heating  has  decreased  rapidly.  Today,  almost  all  houses  are  equipped  with  central  heating  systems  (Peterson,  personal  communication).  Houses  with  central  heating  systems  tend  to  have  better  quality  litter  than  those  with  open  combustion  heating  systems,  like  air  heaters,  because  central  heating  systems  produce  less  PRLVWXUH7KHXVHRIKHDWHUVZKLFKEORZKRWDLURYHUWKHOLWWHUÀRRUPD\DOVRUHVXOWLQGULHUOLWWHUDQGWKXV
potentially  lead  to  fewer  footpad  lesions.  

Spray  (evaporative)  cooling  systems  can  have  a  negative  impact  on  litter  quality  if  not  properly  managed.  
If  the  water  droplets  being  sprayed  from  the  system  are  too  large  they  will  not  be  evaporated  before  WRXFKLQJWKHÀRRU$VDUHVXOWWKHOLWWHUZLOOEHFRPHZHWDQGWKHULVNRI)3'ZLOOEHLQFUHDVHG(YDSRUDWLYH
cooling  systems  must  be  well  maintained.
8QGHUÀRRUKHDWLQJPD\DOVREHEHQH¿FLDOIRU)3' 9DQ+DUQDQG(OOHQ EHFDXVHFRQWURORIÀRRUtemperature  and,  therefore,  moisture  content  of  the  litter  is  easier.  
Relative  Humidity
It  is  essential  to  control  relative  humidity  (RH)  in  the  broiler  house.  If  RH  becomes  too  high  (>70%),  litter  quality  will  be  reduced  (as  the  litter  becomes  wet,  sticky  and  caked)  and  the  risk  of  FPD  will  be  increased.  
However,  it  is  also  important  that  the  RH  is  not  too  low  (less  than  50%),  which  is  often  the  case  during  the  ¿UVWFRXSOHRIGD\VDIWHUSODFHPHQW,I5+LVWRRORZOLWWHUPDWHULDOFDQEHFRPHGU\DQGEULWWOHDQGPD\puncture  the  skin  of  the  footpad  which  can  be  the  start  of  the  development  of  FPD.  Furthermore,  there  is  a  greater  risk  of  dehydration  and  uneven  growth  when  the  RH  is  too  low.  Ideally,  RH  should  be  maintained  EHWZHHQIRUWKH¿UVWGD\VDIWHUSODFHPHQWDQGVKRXOGQRWIDOOEHORZLQWKH¿UVWZHHN
Broiler  producers  who  use  peat  as  a  litter  material  don’t  have  problems  achieving  an  RH  of  50-­60%,  but  SURGXFHUVZKRXVHIRUH[DPSOH FKRSSHG ZKHDWVWUDZRUZRRGVKDYLQJVDVDOLWWHUPDWHULDOPD\¿QGLWPRUHGLI¿FXOWWRDFKLHYHGHVLUHG5+OHYHOV,IWKHKRXVHLV¿WWHGZLWKD HYDSRUDWLRQ VSUD\FRROLQJV\VWHP
then  this  can  be  used  to  increase  RH  where  it  is  too  low.  As  the  broilers  age,  the  RH  will  increase,  but  it  is  important  that  RH  is  controlled  so  that  it  does  not  exceed  70%.    If  RH  does  rise  above  70%,  the  ventilation  rate  should  be  adjusted  and  extra  heating  can  be  given  if  necessary  to  help  control  RH  levels.  
FEED%URLOHUSURGXFHUVGRQ¶WKDYHPXFKLQÀXHQFHRQWKHIHHGIRUPXODWLRQRIWKHGHOLYHUHGIHHG+RZHYHUIHHGIRUPXODWLRQFDQKDYHDVLJQL¿FDQWLPSDFWRQWKHRFFXUUHQFHRI)3',WLVZHOONQRZQWKDWWKHIROORZLQJQXWULWLRQDOIDFWRUVFDQLQÀXHQFHOLWWHUTXDOLW\
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Excess  levels  of  sodium  and  potassium  in  the  feed  (above  the  levels  recommended  in  the  Ross  Broiler  1XWULWLRQ6SHFL¿FDWLRQV PD\DIIHFWZDWHUXSWDNHDQGOHDGWRZHWOLWWHUSUREOHPV6RGLXPDQGSRWDVVLXP
levels  in  broiler  rations  should  be  balanced  to  supply  adequate  levels  for  broiler  performance  without  encouraging  excessive  water  intake.  Some  feed  ingredients,  like  soy  and  tapioca,  have  high  potassium  levels  which,  if  not  accounted  for  in  feed  formulation,  may  lead  to  an  increased  water  intake  and  poor  litter  quality.  
+LJKOHYHOVRI&3 DERYHWKHOHYHOVUHFRPPHQGHGLQWKH5RVV%URLOHU1XWULWLRQ6SHFL¿FDWLRQV DUHDOVR
known  to  have  a  negative  effect  on  litter  quality.  High  CP  levels  lead  to  high  levels  of  uric  acid  being  formed  in  the  liver  and  excreted  by  the  kidneys.  This  stimulates  water  uptake,  causing  wet  droppings  and  thus  increasing  the  risk  of  FPD.  Feeding  diets  which  are  unbalanced  in  CP  will  have  the  same  impact.  
Formulating  diets  on  the  basis  of  digestible  amino  acids  will  ensure  that  the  nutrient  content  of  the  feed  matches  the  needs  of  the  birds  and  reduces  the  risk  of  wet  litter.
  The  CP  requirement  of  the  broiler  decreases  with  age.  This  means  that  by  the  end  of  each  feeding  phase  there  is  usually  a  surplus  of  CP  (current  feeding  programmes  for  broilers  do  not  exactly  match  the  reductions  in  CP  requirement  with  age).  Reducing  CP  levels  on  a  daily  basis  by  adding  whole  wheat  to  the  diet  can  help  to  better  match  CP  supply  to  requirements.  Van  Harn  and  Veldkamp  (2005)  showed  that  whole  wheat  feeding  resulted  in  a  better  litter  quality  and  less  severe  FPD.  However,  growth  rate  and  FCR  was  also  decreased  compared  to  the  control  (Table  8).  

13Table  8:  Results  of  daily  adjusting  the  CP  content  of  the  ration  using  whole  wheat  as  a  diluent  (van  Harn  and  Veldkamp,  2005).  The  CP  intake  of  the  whole  wheat  fed  broilers  was  13%  lower  compared  to  the  control  group.
Control

Reduced  CP

Body  weight  (g)b2325  

2248  aBody  weight  gain  (g/b/d)

57.1  b55.1  aMortality  (%)

5.2

5.6

FCR

  a

1.74

1.86  b

FCR  2300  g

1.73  a1.88  bFeed  intake  (g)3962  a4102  b

Water  intake  (ml)6728  b6324  aWater  /  feed  ratio

1.70  b1.54  aDry  matter  litter  (%)

69.8

74.1

N-­content  litter  (g/kg)b40.6  

39.2  a          No26.5  b70.0  a0LQRU

24.0

15.5

0RGHUDWH

a43.5  

14.5  b6HYHUH

6.0  a0.0  bFootpad  lesions  (%)

*If  superscripts  differ  P<0.05.
Highly  digestible  (unsaturated)  fats  will  promote  enteric  health  in  the  broiler.  The  use  of  poor  quality  fats  often  causes  greasy  or  sticky  litter  which  will  lead  to  FPD  problems.
7KHXVHRIUDZPDWHULDOVWKDWKDYHDORZGLJHVWLELOLW\RUDUHSDUWLFXODUO\KLJKLQ¿EUHVKRXOGEHDYRLGHG
as  these  will  have  a  negative  effect  upon  gut  integrity,  excreta  of  the  broilers,  and  litter  quality.  The  use  of  non-­starch  polysaccharide  (NSP)  enzymes  in  wheat-­based  diets  is  an  important  tool  for  improving  gut  health  and  controlling  litter  quality.  These  enzymes  reduce  gut  viscosity  and  will  lead  to  drier  litter.  
7KHEHQH¿WWREURLOHUSHUIRUPDQFHLQWHUPVRIOLYHZHLJKWJDLQDQG)&5IURPIHHGLQJDJRRGTXDOLW\crumb  and  pellet  is  well  documented.  A  feed  that  is  of  poor  physical  form  with  high  levels  of  dust  not  only  leads  to  problems  with  broiler  performance  but  could  also  lead  to  an  increased  ratio  of  water  to  feed  intake,  which  in  turn  could  lead  to  poor  litter  conditions  and  ultimately  increase  the  risk  of  FPD.  Fine  meal  diets  will  also  increase  the  risk  of  FPD,  because  of  the  higher  water  intake  and  a  faster  passage  of  the  meal  through  the  digestive  tract.
Some  feed  additives  may  help  to  reduce  the  occurrence  of  FPD  in  broilers.  Clay  mineral  binders,  zinc    and  biotin  are  examples  of  such  additives.  The  addition  of  clay  minerals  such  as  bentonites  and  zeolites  into  the  diet  may  improve  the  gut  health  since  they  have  a  water  binding  capacity  which  will  result  in  drier  droppings,  a  better  litter  quality,  and  thus  decrease  the  risk  of  FPD  developing.  Zinc  plays  an  important  UROHLQFHOOUHJHQHUDWLRQDQGLVLQYROYHGLQSURWHFWLQJWKHVNLQ=LQFGH¿FLHQF\ZLOOLQFUHDVHWKHULVNRI)3'
%LRWLQLPSURYHVWKHIRUPDWLRQDQGGHYHORSPHQWRIWKHXSSHUVNLQDQGWULDOVKDYHVKRZQWKDWGH¿FLHQFLHVcan  result  in  FPD  (Shepherd,  E.M.  and  B.  D.  Fairchild,  2010).  Therefore  it  is  important  to  ensure  that  dietary  levels  of  zinc  (min.  100  mg/kg)  and  biotin  (between  0.1  and  0.2  mg/kg)  are  adequate  and  that  GH¿FLHQF\LVDYRLGHG'H¿FLHQF\RI%YLWDPLQVVKRXOGDOVREHDYRLGHGIRUVLPLODUUHDVRQV
If  intestinal  problems  (e.g.  dysbacteriosis)  and  wet  litter  problems  occur,  diluting  the  diet  by  feeding  extra  ZKROHZKHDWPD\EHEHQH¿FLDO

14

STOCKING  DENSITY
Litter  management  is  harder  at  higher  stocking  densities.  High  stocking  densities  can  lead  to  poorer  air  quality  (e.g.  high  ammonia,  carbon  dioxide  concentrations)  and  a  higher  RH  in  the  broiler  house,  HVSHFLDOO\ZKHQWKHYHQWLODWLRQFDSDFLW\LVLQVXI¿FLHQW,WDOVRLQFUHDVHVWKH³IDHFDOORDG´RQWKHOLWWHU
This  all  increases  the  risk  of  FPD.  However,  these  negative  effects  of  a  high  stocking  density  can  be  compensated  for  by  improvements  in  housing  and  management  (e.g.  insulation,  ventilation,  feeder  and  drinking  space).    So,  it’s  important  to  match  housing  and  management  to  the  stocking  density  in  the  house.
Research  in  Belgium  and  The  Netherlands  has  shown  that  less  severe  FPD  occurs  at  a  stocking  density  of  13  birds/m2  compared  to  20  birds/m2  (De  Baere,  2009;;  Van  Harn,  personal  communication).  However,  in  the  range  between  18  –  24  birds  per  m2  (which  are  standard  stocking  densities  in  Northern  Europe)  the  effect  of  stocking  density  on  FPD  is  limited.

15

SUMMARY  OF  FACTORS  THAT  MAY  BE  HELPFUL  IN  
REDUCING  THE  INCIDENCE  OF  FPD  IN  BROILERSFPD  is  a  common  and  wide  spread  problem  and  is  receiving  more  attention  from  the  broiler  industry.  Not  only  does  FPD  affect  animal  welfare  and  farmer  income,  but  in  future  it  will  also  become  important  in  terms  of  legislation.  Wet  and  sticky  litter  is  the  major  cause  of  FPD  and  by  maintaining  good  litter  quality,  broiler  producers  can  reduce  losses  and  improve  bird  welfare.  The  following  advice  can  help  broiler  producers  to  maintain  a  good  litter  quality  and  thus  prevent  FPD.
Preparation  of  the  Broiler  House Clean,  disinfect  and  dry  out  the  house  properly  prior  to  each  placement.
 Check  and  repair  all  house  equipment  (e.g.  ventilation  system,  air  inlets,  heating  system).
 :DUPXSWKHÀRRUWR&EHIRUHOLWWHULVSODFHG.HHSWKHKRXVHZDUPEHWZHHQÀRFNV
 Check  the  drinking  water  system  for  leakages,  repair  /  replace  leaking  nipples  or  cups  and  replace  any  missing  drip  cups.
 Flush  the  water  pipes  just  before  chickens  are  placed.
Litter  Material  and  Litter  Management
 Using  peat  results  in  fewer  footpad  lesions  than  wood  shavings,  and  using  wood  shavings  results  in  fewer  footpad  lesions  than  chopped  straw.
 If  wheat  straw  is  used  it  is  better  to  chop  the  straw  (cutting  length  2  -­  4    cm).    This  will  increase  the  water  absorption  capacity.
 A  mixture  of  peat  and  wood  shavings  or  peat  and  chopped  straw  as  a  litter  material  is  better  than  using  wood  shavings  or  chopped  straw  alone  with  respect  to  the  incidence  and  severity  of  FPD.
 Trial  results  suggest  that  lignocellulose  results  in  less  FPD  than  wood  shavings  and  chopped  straw  EXWWKHUHDUHQR¿HOGGDWDWREDFNWKLVXS For  control  of  FPD  a  thin  layer  of  litter  material  (0.5  -­  1.0  kg  /m2 PD\EHEHQH¿FLDOSURYLGHGÀRRUtemperatures  are  correct.
 :KHQDWKLQOD\HURIOLWWHUPDWHULDOLVXVHGSUHZDUPLQJRIWKHÀRRUWRDWOHDVW&LVQHFHVVDU\ 'RQRWVSUHDGRXWWKHOLWWHUPDWHULDOXQWLOWKHÀRRUKDVUHDFKHGWKHWDUJHWWHPSHUDWXUHRI&
 Remove  wet  litter  and  replace  it  with  clean,  dry,  fresh  litter.  
 Stimulate  scratching  behaviour  by  loosening  up  the  litter  and  loosen  up  any  litter  that  becomes  caked.
 Take  away  feed  paper  used  during  brooding.    Paper  should  be  removed  by  approximately  3  days  of  age,  ideally  before  it  disintegrates.
Water  Supply  and  Water  Management
 Maintain  and  check  drinking  systems  regularly.  Replace  leaking  or  blocked  nipples  and  missing  cups.
 Replace  the  entire  drinking  system  every  5  -­  7  years.
 Provide  water  of  good  quality  only.  
 Flush  and  sanitise  drinking  lines  regularly  to  reduce  drinker  leakage  by  preventing  the  build  up  of  FRQWDPLQDQWVDQGELR¿OPV )OXVKWKHZDWHUSLSHVSULRUWRFKLFNVEHLQJSODFHGDQGWKHQUHJXODUO\GXULQJWKH¿UVWWZRZHHNVRIOLIH
 FPD  is  lower  with  nipple  systems  compared  to  drinking  cups;;  the  use  of  drip  cups  underneath  a  drinking  nipple  will  minimise  water  leakage  into  the  litter  and  reduce  FPD.
 $YRLGKDYLQJDZDWHUSUHVVXUHWKDWLVWRRKLJKHVSHFLDOO\GXULQJWKH¿UVWWZRZHHNVDIWHUSODFHPHQW Make  sure  that  the  drinking  line  is  level  to  ensure  that  water  delivery  is  equal  along  the  entire  length  of  the  line.
 Adjust  the  drinking  line  daily  for  bird  height.  A  drinking  line  that  is  too  low  will  lead  to  wet  litter.  
 Acidifying  water  may  help  to  reduce  the  severity  of  FPD  but  can  also  impact  broiler  growth.    
 Controlling  water  supply  during  periods  when  water  intake  is  naturally  low  will  help  to  minimise  unnecessary  water  leakage,  but  care  must  be  taken  not  to  restrict  the  amount  of  water  needed  for  growth.      

16Light  Distribution,  Light  Colour  and  Light  Programme
 7KHXVHRIDQLQWHUPLWWHQWOLJKWVFKHGXOHPD\EHEHQH¿FLDOIRUUHGXFLQJWKHVHYHULW\RI)3'
 )3'LVORZHUEXWHQHUJ\FRVWVDUHKLJKHUZLWKLQFDQGHVFHQWFRPSDUHGZLWKÀXRUHVFHQWOLJKW /LJKWPXVWEHXQLIRUPO\GLVWULEXWHGWKURXJKRXWWKHKRXVH9HUWLFDOKDQJLQJ7/DUPDWXUHV ÀXRUHVFHQW
tubes)  generally  give  a  better  light  distribution  compared  with  TL  armatures  on  the  ceiling.  
 /LJKWLQWHQVLWLHVRIORZHUWKDQOX[KDYHQREHQH¿WWR)3'
 7KHUHLVOLPLWHGLQÀXHQFHRIOLJKWFRORXURQ)3'*UHHQEOXHOLJKWVHHPVWRUHVXOWLQOHVV)3'
although  it  is  not  clear  if  the  European  Council  Broiler  Directive  prescribed  light  intensity  can  be  achieved  with  this  lighting  system.    
Ventilation  and  Heating The  use  of  central  heating  systems  is  preferred  over  the  use  of  combustion  heaters  because  they  produce  less  moisture.
 Heat  distribution  must  be  uniform  throughout  the  house  and  the  heating  system  must  be  the  correct  size  for  the  house.    
 8QGHUÀRRUKHDWLQJSURYLGHVEHWWHUFRQWURORIÀRRUWHPSHUDWXUHZKLFKPD\KHOSWRUHGXFHWKH
incidence  of  FPD.
 8VLQJDWHPSHUDWXUHSUR¿OHZLWKDPRUHJUDGXDOGHFOLQHLQWHPSHUDWXUHPD\UHGXFHWKHLQFLGHQFHRI
FPD.
 3URYLGHPLQLPXPYHQWLODWLRQIURPGD\RQHRIWKHÀRFN
 ,WFDQEHKHOSIXOWRFLUFXODWHWKHDLULQWKHKRXVHGXULQJWKH¿UVWFRXSOHRIGD\VDIWHUSODFHPHQW Monitoring  /  controlling  the  RH  in  the  house  is  important.  The  RH  should  be  between  50  -­  70%.  If  RH  is  above  70%,  extra  ventilation  and  sometimes  heating  is  necessary.
 ,IWKHKRXVHLV¿WWHGZLWKD VSUD\ FRROLQJV\VWHPLWPXVWEHLQJRRGZRUNLQJRUGHU/DUJHGURSOHWVL]Hor  blockages  in  the  spray  nozzles  will  increase  the  risk  of  wet  litter  and  FPD.
Feed If  feed  manufacturers  use  only  good  digestible  raw  materials,  formulate  their  diets  on  the  basis  of  digestible  amino  acids,  and  avoid  high  sodium  and  potassium  levels  in  the  diets,  the  risk  of  FPD  will  be  decreased.  
 0DNHVXUH]LQFELRWLQDQG%YLWDPLQOHYHOVLQWKHIHHGDUHVXI¿FLHQW
 $GGLQJFOD\PLQHUDOVLQWRWKHGLHWFDQKDYHDEHQH¿FLDOHIIHFWRQOLWWHUTXDOLW\DQG)3' Daily  adjustment  of  dietary  CP  (dynamic  feeding)  by  adding  whole  wheat  can  be  an  effective  way  to  reduce  FPD.
 If  intestinal  problems  and  wet  litter  problems  occur,  a  broiler  producer  can  dilute  the  diet  by  feeding  extra  whole  wheat.
Stocking  Density   Stocking  densities  must  be  in  line  with  local  legislation,  but  for  FPD,  lower  stocking  densities  will  be  EHQH¿FLDO Match  housing  and  management  to  the  stocking  density  in  the  house.  If  housing  and  management  are  not  matched,  an  increase  in  stocking  density  will  result  in  an  increase  in  FPD.

17

LITERATURE  FOR  FURTHER  READING
Ross  Broiler  Management  Manual.  2009.
%DHUHGH.ULVHQ-RKDQ=RRQVD6WURRLVHOPDWHULDDOLQSOXLPYHHVWDOOHQ3OXLPYHHQU
%DHUHGH.ULVHQ-RKDQ=RRQVE6WURRLVHOELMYOHHVNXLNHQVKRHYHHOKHLGKRXWNUXOOHQHQVWUR
Pluimvee  nr.  39.
%DHUHGH.ULVHQ-RKDQ=RRQVF/LFKWVWHUNWHHQOLFKWNOHXUELMYOHHVNXLNHQV3OXLPYHHQU
%DHUHGH.ULV*HEUXLNYDQWXUIVWURRLVHOHQYRHGHUVPHWHHQODJHUHLZLWJHKDOWHELMYOHHVNXLNHQV
Pluimvee  nr.  43.
%DHUHGH.ULV/LFKWVFKHPD¶VELMYOHHVNXLNHQV3OXLPYHHQU
%DHUHGH.ULV%H]HWWLQJELMYOHHVNXLNHQVKRHRPJDDQPHWGHEH]HWWLQJVQRUPXLWGH(8ULFKWOLMQ"
Pluimvee  nr.  53.
Berg,  C.  (1998).  Foot-­pad  dermatitis  in  broilers  and  turkeys.  Doctoral  diss.  Dept.  of  Animal  Environment  and  Health,  SLU.  Acta  Universitatis  Agriculturae  Sueciae,  Sweden.
Berk,  J.,  2009.  Effect  of  litter  type  on  prevalence  and  severity  of  pododermatitis  in  male  broilers.  Berl  Munch  Tierarztl  Wochenschr.,  122:  257-­263.
Council  Directive  2007/43/European  Council  2007.  Council  Directive  2007/42/European  Council  of  28  June  2007  laying  down  minimum  rules  for  the  protection  of  chickens  kept  for  meat  production.  http://eur-­OH[HXURSDHX/H[8UL6HUY/H[8UL6HUYGR"XUL 2-/(13')Ekstrand,  C.,  Algers,  B.  and  Svedberg,  S.  (1997)  Rearing  conditions  and  foot-­pad  dermatitis  in  Swedish  broiler  chickens.  Preventive  Veterinary  Medicine,  31:  167–174.
Ekstrand,  C.  and  Carpenter,  T.  E.  (1998).  Spatial  aspects  of  foot-­pad  dermatitis  in  Swedish  broilers.  Acta  Veterinaria  Scandinavica  39:  273-­280.
Harn,  van  J.,  2009.  Invulling  lichteisen  EU-­welzijnsrichtlijn  voor  vleeskuikens  –  vier  lichtschema’s  vergeleken.  ASG-­Rapport  172.
Harn,  J.  van,  H.H.  Ellen,  2009.  Gebruik  van  vloerverwarming  bij  vleeskuikens.  ASG  Rapport  171.
Harn,  van  Jan  en  Ingrid  de  Jong,  2012a.  Zuur  is  zoet  voor  zolen  (2).    Pluimveehouderij  42/7.  1  juni  2012.  
P.  30-­31.
Harn,  van  Jan  en  Ingrid  de  Jong,  2012b.  Goede  maar  dure  warmte.  Pluimveehouderij  42/3.  2  maart  2012.  
P.  26-­27.
Harn,  van  J.,  I.C.  de  Jong  en  T.  Veldkamp,  2009.  Effect  strooiselmateriaal,  strooiselhoeveelheid,  opvangschoteltje  en  waterdruk  op  resultaten  vleeskuikens.  ASG  Rapport  220.
Harn,  J.  van;;  Veldkamp,  T.,  2005.  Dynamisch  voeren  belooft  veel  goed,  maar...  er  valt  nog  wat  te  sleutelen!  De  Pluimveehouderij  35  (8).  -­  p.  14  -­  15.  

18

+DVODP60%URZQ61:LONLQV/-.HVWLQ6&:DUULVV3'DQG1LFRO&-
Preliminary  study  to  examine  the  utility  of  using  foot  burn  or  hock  burn  to  assess  aspects  of  housing  conditions  for  broiler  chicken.  British  Poultry  Science  47:  13-­18.
Jong,  I.C.  de;;  Harn,  J.  van;;  Gunnink,  H.;;  Hindle,  V.A.;;  Lourens,  A.  (2011).  Ernst  en  voorkomen  van  voetzoollaesies  bij  reguliere  vleeskuikens  in  Nederland.  Wageningen  UR  Livestock  Research,  Rapport  513.
Jørgensen,  Marlene,  2011a.  Afprøvning  af  drikkenipler  –  del  1.  Boksforsøg  nr.  118.
Jørgensen,  Marlene,  2011b.  Afprøvning  af  drikkenipler  –  del  2.  Boksforsøg  nr.  119.
Jørgensen,  Marlene,  2011c.  Afprøvning  af  drikkenipler  –  del  3.  Boksforsøg  nr.  120.
0D\QH5.(OVH5:DQG30+RFNLQJ+LJKOLWWHUPRLVWXUHDORQHLVVXI¿FLHQWWRFDXVHIRRWSDG
dermatitis  in  growing  turkeys.  British  Poultry  Sience  Volume  48,  Number  5,  pp.  538-­545.  
Petersen,  Jette  Søholm,  2003.  Sammenhæng  mellem  vandtryk  og  trædepudekvalitet.  Boksforsøg  nr.  75.
3HWHUVHQ6DPPHQOLJQLQJDIGULNNHYHQWLOHUQH&RUWL6WHPSHO9DO&RUWL.XJOHRJ/LIH/LQH
Boksforsøg  nr.  82.
Rodenburg,  T.B.,  J.  van  Harn,  J.H.  van  Middelkoop,  2004.  Effect  van  gekleurde  verlichting  op  technische  resultaten  en  welzijn  van  vleeskuikens.  PraktijkRapport  Pluimvee  10.
Shepherd,  E.M.  and  B.  D.  Fairchild,  2010.  Footpad  dermatitis  in  poultry  (Invited  review).  Poultry  Science  89  :2043–2051.
<RXVVHI,0,&:HVWIDKO$%HLQHNHDQG-.DPSKXHV([SHULPHQWDOVWXGLHVLQWXUNH\VRQ
effects  of  litter  quality  and  feeding  on  development  and  intensity  of  footpad  dermatitis.  12th    Congress  of  the  European  Society  of  Veterinary  and  Comparative  Nutrition,  25-­27.09.08,  Vienna,  Austria,  138.

19

Substantial  discolouration  of  the  footpad,  VXSHU¿FLDOOHVLRQGDUNSDSLOODH

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lesions,  slight  discolouration  on  a  limited  area,  mild  hyperkeratosis,  old  scars.

www.livestockresearch.wur.nl

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of  haemorrhages  or  severely  swollen  footpad.

Class  3  -­  severe  lesion

  

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Class  1  -­  mild  lesion

Class  0  -­  no  lesion

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    $3KRWR*XLGHWR%URLOHU)RRW+HDOWK&ODVVL¿FDWLRQClass  0  –  small  discolouration

Class   1  –  dark  papillae,  no  ulceration

Class   2  –  ulcer  covered  by  crustClass  0  –  smooth,  no  lesion&ODVV±VXSHU¿FLDOOHVLRQGLVFRORXUDWLRQClass   2  –  dark  papillae  and  ulcer

Class   2  –  abcess/bumble  foot  swollen

Class   1  –  substantial  discolouration

Class  0  –  almost  healed  lesion,  scar

$3KRWR*XLGHWR%URLOHU)RRW+HDOWK&ODVVL¿FDWLRQNOTES______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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