The Effects of Simulated Transportation Conditions on the Welfare of White-Feathered Layer Pullets
Date
2020-05-26
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Thesis
Degree Level
Masters
Abstract
This study evaluated the effects of various temperature (T) and relative humidity (RH) combinations, and durations (D), on the welfare of pullets during simulated transportation. In a 5x2 factorial arrangement (T/RH combinations, and D (three replications)) pullets (n=240) were randomly assigned to one of five treatments, 21°C 30%RH (21/30), 21°C 80%RH (21/80), 30°C 30%RH (30/30), 30°C 80%RH (30/80), and -15°C (-15), for a four or eight hour D. Pre-treatment, pullets were orally administered data loggers (recorded core body temperature (CBT)), which were retrieved post-treatment. Foot T, body weights, and blood samples were taken pre- and post-treatment. Video recorded during exposure and analyzed for behaviour. Post-treatment, pullets were slaughtered, and carcasses were analyzed for muscle tissue characteristics (pH, water-holding capacity, and colour). In a randomized complete block design, data were analyzed via Proc Mixed (SAS 9.4). Differences were determined at P≤0.05. Pullet CBT during the last hour of exposure was lowest in the -15 treatment. Pullet ∆CBT was greater in the eight hour D compared to the four hour D. Compared to the -15 treatment, pullets in 30/30 and 30/80 surveyed more, and pullets in 30/80 were more active. Pullets exposed to 30/30 and 30/80 panted more. Along with the 21/30 treatment, pullets in the -15 and 21/30 treatment spent more time motionless, compared to the 30/30 and 30/80 treatments. Pullets exposed to -15 preened less compared to 21/80 and 30/30. Foot T were lowest in the pullets exposed to -15, and higher in the pullets in 30/80 compared to the neutral and cold treatments. Final blood glucose levels were higher in pullets in 30/80 compared to 21/30 and 21/80. The partial pressure of CO2, total CO2, and bicarbonate levels were lower in pullets exposed for eight hours. Live shrink (kg) was higher in pullets exposed to 30/30 and 30/80 (compared to 21/80), and in the eight hour D (kg and %). No biologically significant impacts were found for pullet muscle tissue characteristics. Exposure to thermal stress required pullets to implement behavioural and physiological mechanisms to maintain homeostasis. A D of up to eight hours had minimal impacts on pullet well-being.
Description
Keywords
welfare, hematology, transport, muscle tissue, behaviour
Citation
Degree
Master of Science (M.Sc.)
Department
Animal and Poultry Science
Program
Animal Science