Modern aspects of contact dermatitis in industrial poultry farming

Abstract

Contact dermatitis is a lesion of the skin of broilers, which leads to a decrease in the quality of the carcass by 15-30 %. It is described as brown-black erosions and ulcers that occur on the breast (breast blisters, BB), hock burns (HB) and on the skin of the central pulp of the foot (food pad dermatitis, FPD). The most commonly affected is the pulp of the foot, followed by the hocks and chest. There are a number of factors that lead to crumb dermatitis. These include: the density of planting birds; type of troughs and the order of their use; feeding; the level of temperature and humidity in the room; type of litter, its quality and quantity; intestinal health. Birds are kept at a density of 8 individuals/m2 suffered less from dermatitis than those kept at a density of 13 individuals/m2 . Moreover, the harmful effects of high density were particularly pronounced at 18 individuals/m2 . The prevalence and severity of this pathology in broilers increases at later stages of fattening. Pododermatitis spread to several layers of skin. The condition of the crumbs worsened when the bird reached slaughter age with up to 64 % of the carcasses affected. In this case, lesions of the hocks and chest were rare. Wet litter (> 30 % moisture) is associated with an increase in the incidence and severity of contact dermatitis in broiler and turkey housing systems. This state of litter is most often registered in the winter-spring and autumn seasons. The quality of the litter, especially taking into account its humidity, has been identified as an important issue of well-being, which has a great negative impact on the condition of feathers, limb health and the frequency of contact dermatitis. Litter temperature is also important. With its growth, the degree of contact dermatitis increases. The reason for the increase in litter temperature is the increase in planting density and the accumulation of more manure, which enhances bacterial fermentation. With wet litter, bird feathers become wet or contaminated with litter, feces and dirt. It loses its protective properties. The level of bird welfare is declining sharply. Diagnosis of contact dermatitis in poultry is based on characteristic clinical signs. These are lameness, impaired mobility and discoloration of the skin, which often develops into an ulcer. The lesions are clearly separated from the intact tissue and often appear as ulcers surrounded by a deep hemorrhagic shaft. Contact dermatitis can develop in less than a week. Characteristic signs at the beginning of the disease are swelling, redness and increase in local temperature, thickening of the skin. Deep ulcers usually lead to abscesses in the underlying tissues and structures. Often the affected area is covered with crusts. If large ulcers develop, they can cause pain, slow growth, obstruct gait, and open bacteria to underlying tissues. Key words: broilers, contact dermatitis, dermatitis of the central pulp of the finger, dermatitis in the area of the hocks, dermatitis in the chest.