Effects of Simulated Cold and Warm Transport on Turkeys
Date
2017-05-26
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-5879-7361
Type
Thesis
Degree Level
Masters
Abstract
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.
Description
Keywords
turkey, transport, live shrink, meat quality, core body temperature
Citation
Degree
Master of Science (M.Sc.)
Department
Animal and Poultry Science
Program
Animal Science