Effects of Simulated Cold and Warm Transport on Turkeys

The effects of cold and warm exposure during simulated transport on 12-week-old turkey hens and 16-week-old toms were assessed in two experiments: a cold-transport analysis with three treatments, -18°C and two 20°C conditions with 30% or 80% relative humidity (RH); and a 2x2 factorial warm-transport analysis comparing the two 20°C treatments with two 28°C treatments, and 30% or 80% RH. Turkeys were crated at 83 kg/m2 and exposed to conditions for 8 hours before processing. Three replications (8 birds) were performed per treatment for each gender, and between-sex comparisons were made within treatments. Significance was declared at p≤0.05. Core body temperature (CBT), live shrink (LS), and delta blood glucose (BG) were assessed; meat quality measures included thigh and breast pH and L*, a*, and b* colour values. Behaviour was measured using instantaneous scan sampling during the last 4h of treatment. LS in hens exposed to -18°C (2.9%) was greater than those at 20°C (1.5%). Thigh pH was higher after -18°C exposure (hens: 6.39; toms: 6.08) than after 20°C. In the cold-exposed hens, breast L* values were lower, while thigh a* and breast b* values were higher than in both 20°C treatments. Huddling, shivering, preening, and feather ptiloerection occurred more in cold-exposed turkeys. Between-sex comparison revealed lower LS and a larger decrease in BG in cold-exposed toms; meat characteristics also differed. After warm (28°C) exposure, both hen and tom LS increased, and tom CBT rose approximately 1.0°C. Ultimate breast pH was unexpectedly higher in warm-exposed toms (5.71 at 30%, 5.67 at 80% RH) than those exposed to 20°C (5.71 and 5.69), but lower with increased RH. In hens, initial breast pH increased with warmer temperature, while thigh a* decreased. Several differences in breast pH and a* were noted between sexes within a treatment, and hens had larger BG decreases than toms in both 20°C conditions. In the 28°C 80% RH treatment, LS was higher in hens (3.1%) than in toms (2.44%). Frequency of activity, panting, head-resting, and optional behaviours differed between warm treatments and sexes. Transport conditions (temperature and humidity levels) investigated in this study significantly impacted turkey physiology, meat quality, and behaviour