WET LITTER AND PERCHES AS RISK-FACTORS FOR THE DEVELOPMENT OF FOOT PAD DERMATITIS IN FLOOR-HOUSED HENS

1. An experiment was conducted to determine whether different moisture levels of litter and perches with different hygienic conditions are i nvolved in the manifestation of foot pad dermatitis in White Leghorn l ayers. 2. Four different treatments were compared: dry litter and dry perches; dry litter and wet perches; wet litter and dry perches; and w et litter and wet perches. Temperature, pH, air humidity and ammonia c hanges in the pens were monitored. 3. The mean prevalence of foot pad lesions in groups 1, 2, 3 and 4 was 17%, 13%, 49% and 48% respectively . The overall incidence of foot pad lesions in birds reared on dry lit ter was 38%, and in birds reared on wet litter 92%. 4. When the air te mperature was above 20 degrees C, an increasing moisture content in th e litter was associated with an increasing incidence of foot pad derma titis. However, when the air temperature was below 20 degrees C there were no new cases of dermatitis in any of the 4 treatments. There were no significant differences in litter pH or ammonia between the 4 trea tments when compared over the whole experiment. 5. Although the incide nce of lesions was not significantly affected by the presence of wet p erches, the area of the lesions tended to be in groups with wet patche s than in groups with dry perches. 6. It is suggested that moisture an d temperature are important contributing factors for the occurrence of foot pad dermatitis in laying hens. Wet perches may contribute to the severity of such lesions.