Remedying Contact Dermatitis in Broiler Chickens with Novel Flooring Treatments

SIMPLE SUMMARY: Contact dermatitis is an overarching term for inflamed or necrotic lesions after contact with an allergen or irritant. Broiler chickens commonly experience these lesions due to prolonged contact with moisture, feces, and ammonia within litter. This study aimed to find methods to prevent and remedy lesions on broilers’ feet, hocks, and breast. Furthermore, the impact of treatments on plumage cleanliness, gait, and body weight was investigated. We applied novel flooring treatments consisting of plastic slats and disinfectant mats containing povidone-iodine, which we compared to the industry control (used litter) and a positive control (clean litter). Weekly measurements on a sample of birds in each pen showed us the impact of both flooring treatments and age (weeks) on animal welfare outcomes. Contrary to expectations, the novel flooring treatments did not prevent or remedy contact dermatitis. In fact, the positive control, consisting of replacing litter every four days, resulted in the best welfare condition, with limited to no contact dermatitis at week seven of age. ABSTRACT: Contact dermatitis (footpad dermatitis (FPD), hock burns, and breast dermatitis) is a welfare issue for broiler chickens, causing pain and behavioral restrictions. Once lesions develop, often nothing is done to remedy the issue for the affected flock. Our objective was to evaluate novel flooring treatments at the flock level by providing preventative and remedial treatments against contact dermatitis, plumage soiling, and gait impairment. Broilers (n = 546) were housed in 42 pens, with 13 birds/pen. The flooring treatments (four) included used litter (NEG), new pine shavings replaced regularly (POS), a mat filled with 1% povidone-iodine solution (MAT), and the iodine mat placed on a slatted floor (SLAT). Flooring treatments were provided from day one of age (preventative approach; PREV) or day 29 (remedial approach; REM). Contact dermatitis, soiling, gait, and weight were recorded weekly (seven birds/pen). Results showed a treatment effect for all measures, dependent on bird age. Overall, the POS treatment resulted in the best welfare outcomes (FPD, hock burns, and gait). The worst contact dermatitis was found in the MAT and SLAT groups. NEG birds showed little contact dermatitis, opposite to expectations. Weights were lower for PREV-POS in week seven only. The treatments with povidone-iodine were deemed ineffective against contact dermatitis. Access to clean litter prevented and remedied contact dermatitis, and a comparable approach may be commercially feasible.