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Foot pad dermatitis (FPD) in broiler chickens is characterized by ulcerated lesions on the underside of the foot which can be a welfare concern. Research has demonstrated that litter moisture is the primary causal factor in the development of foot pad lesions. However, litter moisture is affected by a multitude of on-farm management decisions such as those related to litter material and depth, the house environment, litter moisture management, and nutrition. The objectives of this field study were to: 1) benchmark foot pad dermatitis prevalence in Alberta broiler flocks, 2) evaluate correlations between 3 foot pad assessment methods (e.g., on-farm, processor-line, and processor-sampled), 3) evaluate the reliability of foot pad assessment on the processing line, and 4) determine which on-farm management practices most influence foot pad quality.
Eight Alberta broiler producers located throughout the province and affiliated with the same processing plant participated in the field study. Each producer was visited at the farm site over 4 consecutive flock cycles throughout the study period for a total of 32 flock visits. Two visits per farm were completed during flock cycles from January to June, and 2 additional visits were completed during flock cycles from June to September. Two trained research staff conducted all on-farm visits when broilers were 35 to 39 d of age and then followed each flock to the processing plant. Broilers in flocks represented Ross 308 (∼90%) and Cobb and Hubbard (∼10%) strains. A survey composed of 46 questions regarding producer knowledge of foot pad dermatitis, barn environment, flock information, water management, nutrition program, flock health, litter management, and lighting program was completed during each flock visit. A sub-sample of 200 broilers were assessed for foot pad dermatitis during each on-farm visit (n = 30 visits). Left and right foot pads were scored independently using a 4-point assessment scale modified from the Welfare Quality Assessment Protocol for Poultry. Litter was assessed for moisture content from 18 locations throughout the barn (e.g., near walls, feeders, drinkers). Each subject flock was shipped to the processing plant within 24 to 48 h of on-farm data collection. Processor-line foot pad scores were recorded as the number of blemished foot pad pairs over the course of 1 min while moving past a specific observation point on the processing line.
Mean foot pad dermatitis prevalence across assessment methods was 28.65% (on-farm), 26.17% (processor-line) and 31.83% (processor-sampled). The final objective of the current study was to determine which on-farm management practices lead to better foot pad quality. Foot pad scores for each assessment method were significantly different between producers (P < 0.01). For example, Producer D had consistently higher foot pad quality with mean prevalence of 0.73% ± 0.93 (on-farm), 2.7% ± 2.6 (processor-line), and 2.6% ± 1.7 (processor-sampled), while Producer F had consistently lower foot pad quality with mean prevalence of 86.9% ± 32.5 (on-farm), 54.3% ± 33.2 (processor-line) and 66.4% ± 16.9 (processor-sampled). However, distinct differences in management practices were found between producers with higher and lower foot pad scores. For example, Producer D used litter depths shallower than 10 cm and used pine shavings as a substrate, while Producer F used wheat straw bedding and had a litter depth greater than 10 cm. As such, the results indicate foot pad dermatitis is affected by the on-farm management practices of individual producers. On-farm foot pad assessment methods varied between producers, with 40.6% of respondents assessing foot pads of dead birds, 31.25% of respondents assessing the foot pads of live birds, and 21.8% who did not assess foot pad dermatitis. Most producers surveyed in the field study (62.5%) used wheat straw as a bedding substrate compared to pine shavings (21.9%) or newspaper (12.5%). While cheaper and easy to obtain, flocks raised on wheat straw had significantly higher prevalence of foot pad dermatitis (40.6%) compared with flocks raised on alternative materials (6.4%; P < 0.001). The results suggest the use of pine shavings bedding should be considered for improved foot pad quality; however, this would be economically costly. Significant differences in litter moisture scores were found between producers (P < 0.01). Flocks with mean litter scores of “2” or greater (i.e., litter was wet and formed a ball upon compaction) had a greater percentage of birds affected by foot pad dermatitis (40.1%) compared with flocks with litter scores of “1” or less (i.e., litter easily fell apart or was dry; 7.4%; r = 0.65; P < 0.01). On-farm management practices such as ventilation system, barn age, lighting system and intensity, stocking density, and type of drinker system were not associated with significant differences in foot pad dermatitis prevalence. No significant differences in foot pad dermatitis were observed between winter and summer visits.
Mean foot pad dermatitis prevalence in Alberta broilers was benchmarked by assessment method at 28.65% (on-farm), 26.17% (processor-line) and 31.83% (processor-sampled). On-farm and processing-sampled scores were strongly correlated to one another compared with correlations with processing-line scores, as processing-line scores were highly variable and not consistent between measurements within flock. Management practices associated with litter moisture were found to influence the prevalence of foot pad dermatitis. Specifically, use of pine shavings bedding, litter depths of