Foot pad dermatitis , hock burn lesions, and breast blisters are a form of contact dermatitis (skin irritation) in broilers, turkey, and breeders. The skin irritation starts with small areas of damage characterized by discoloration and slight thickening of the epidermis (outer skin layer) on the foot and hock. These irritations may progress into deep necrosis (the death of body tissue) of the epidermis and inflammation of the subcutis (beneath the skin), causing pain and lameness. Affected birds spend more time sitting, which causes pressure on the keel bone bursa and leads to breast blisters. This condition is also called sternal bursitis, where the keel bone bursa (a fluid-filled sac that provides a cushion between the surfaces of a bone and soft tissue) becomes enlarged and filled with fluid.
The severity of foot pad dermatitis ranges from superficial to deep on the plantar surface of the footpads and toes; severe foot pad dermatitis may lead to lameness, causing pain and welfare problems. Some skin dermatitis is associated with bacterial infections, but others, such as hock burns and breast blisters, are not. The presence of foot pad dermatitis is associated with impaired growth performance, welfare concern, decreased leg meat yield, and increased carcass condemnations, causing economic loss.
Some potential factors associated with foot pad dermatitis include stocking density, litter management, and dietary factors.
- Stocking density
High stocking density is one of the predisposing factors involved in developing foot pad dermatitis in poultry. An optimum range for broiler stocking density is 34 to 40 kg/m2 assuming 2.5 kg final BW on an average; increasing stocking density beyond this range may impair animal health and performance.
- Litter management
Litter quality (pH, moisture, and ammonia content), litter depth, litter materials, and seasonal conditions play an important role in contact dermatitis. Litter material is an essential aspect of litter thermal insulation and moisture absorption. Litter materials differ by region but the best-performing litter material is pine shavings, followed by rice hulls, ground corncobs, stump chips, pine sawdust, bark and chips, pine bark, and clay. The prevalence of foot pad dermatitis is usually higher during the winter due to ventilation challenges which may result in poorer litter quality.
Water line management can directly affect litter quality. Water drinker type, nipple drinker cup size, and water line biofilm or other particulates may result in leaky drinkers. Regularly flushing and sanitizing water lines will remove biofilms and reduce water leakage.
Wet litter has increased ammonia (NH3) levels which increases litter pH, making the litter caustic and can lead to foot pad dermatitis. Adding aluminosilicates (4.5 kg/m2) to the litter and zeolite or halloysite in the feed (1% of the diet) can significantly control litter ammonia. Appropriate ventilation levels can eliminate ammonia from the barn, decreasing the incidence of foot pad dermatitis in a flock.
- Dietary factors
Diet can affect foot pad dermatitis through its impact on skin health and litter quality. Carotenoids and Biotin play an essential role in skin integrity and should be provided in adequate levels in the diet.
Non-starch polysaccharides (NSP) are sticky, indigestible carbohydrates that increase gut viscosity and results in sticky manure that sticks to the footpads. These carbohydrates are found in high concentrations in wheat, barley, and other grains. Dietary commercial enzymes such as xylanase and beta-glucanase should be added to the diets containing non-starch polysaccharides to prevent adverse effects on animal performance and litter quality.
High salt diets can increase moisture of fecal droppings, resulting in poor litter conditions. Animal nutritionists may balance dietary sodium and chloride levels using suitable additives, as was discussed in an article called “The dietary source type of sodium does matter in poultry performance” (October 2021).
New research shows that balancing of dietary amino acids using synthetic amino acids and reducing broiler finisher phase dietary protein level by 2.3% could result in better litter quality and less footpad lesions, compared to standard feeding programs.
References
Shepherd, E.M., and B.D.Fairchild. 2010. Footpad dermatitis in poultry. Poultry Science. 89:2043–2051. https://doi.org/10.3382/ps.2010-00770
Grimes, J. L., T. A. Carter, and J. L. Godwin. 2006. Use of a litter material made from cotton waste, gypsum, and old newsprint for rearing broiler chickens. Poultry Science. 85:563–568. https://doi.org/10.1093/ps/85.3.563
Grimes, J. L., J. Smith, and C. M. Williams. 2002. Some alternative litter materials used for growing broilers and turkeys. World’s Poultry Science Journal. 58:515–526. doi:10.1079/WPS20020037
Hess, J. B., S. F. Bilgili, and K. M. Downs. 2004. Paw quality issues. Proc. Deep South Poultry Conference, Tifton, GA. University of Georgia, Athens.
Mayne, R. K. 2005. A review of the aetiology and possible causative factors of foot pad dermatitis in growing turkeys and broilers. World’s Poultry Science Journal. 61:256–267. doi:10.1079/WPS200458
Mayne, R. K., R. W. Else, and P. M. Hocking. 2007. High litter moisture alone is sufficient to cause footpad dermatitis in growing turkeys. British Poultry Science. 48:538–545. DOI: 10.1080/00071660701573045
Banaszak, M., Biesek, J., Bogucka, J., Dankowiakowska, A., Olszewski, D., Bigorowski, B., Grabowicz, M., and M. Adamski. 2020. Impact of aluminosilicates on productivity, carcass traits, meat quality, and jejunum morphology of broiler chickens. Poultry Science. 99:7169–7177. https://doi.org/10.1016/j.psj.2020.08.073
Tucker, S. A., and A. W. Walker. 1999. Hock burn in broilers. Pages 33–50 in Recent Developments in Poultry Nutrition 2. J. Wiseman and P. C. Garnsworthy, ed. Nottingham University Press, Thrumpton, UK.
van Harn, J., Dijkslag M.A., and M. M. van Krimpen. 2019. Effect of low protein diets supplemented with free amino acids on growth performance, slaughter yield, litter quality, and footpad lesions of male broilers. Poultry Science. 98:4868–4877. https://doi.org/10.3382/ps/pez229
