Substrate choice by turkeys differing in 3-point gait-scoring system in a mobility test

Assessment of pain in poultry flocks’ production is one of the biggest welfare concerns. The aim of this study was to evaluate the walking ability and preferences for three types of substrates by turkeys with different degrees of lameness, in order to verify if birds with higher gait score experience pain and how their choices differ from healthy birds. An experimental test was conducted with 16 male-turkeys 116-day-old (B.U.T.6). Nine birds (56.25%) were considered normal (score 0) whereas 7 (43.75%) were evaluated as having mild to severe lameness (scores 1 or 2) according to 3-point gait-score assessment. A familiar (A: wet litter) and unfamiliar (B: plastic slat) substrate were distributed into three horizontal lines (L1, L2, and L3; each one measuring 150cm length x 60cm width) separated by three concrete empty areas of the same measures. L1 was divided into 75cm of A substrate and the same dimensions of B; L2 had 100cm of A and 50cm of B, while L3 had 50cm of A and 100cm of B. The turkeys’ motivation to pass through the lines was triggered by the presence of conspecifics located at the end of the experimental area. Data were analyzed using ANOVA. There were no significant differences between normal and lame turkeys to the total time spent on three lines (215.00±61.59s), (233.57±74.81s);the total time spent on the empty area (385.22±83.70s), (557.71±124.04s) and the total time to cross the testing areas (581.3±91.72s), (791.2±154.44s),respectively. Substrate A was chosen by 71.4% of lame birds even in L1 as L2, while 55.6% of normal turkeys preferred substrate B in L1 and 77.8% chose substrate A in L2. All birds walked on substrate B in L3. According to these preliminary results, it seems that lame birds have no difference in substrate choice, or on the time spent in each part of the experiment.