Commercial straight-deck trailer vibration and microclimate conditions during market-weight pig transport during summer

Abstract

The objective of this study was to collect and quantify three-axis acceleration data from six locations within commercial pig transport trailers during summer. Two trucks with straight-deck trailers transporting two loads per day were observed for 5 consecutive days (N = 20). Accelerometers were placed under the floor of each trailer’s top and bottom decks (DECs) in the center of three sections (SECs): fore, middle, and aft. Data from each trailer section were processed to calculate z- and x,y-axis root mean square (RMS) values and vibration dose values (VDVs) during loading, transport, and unloading. There were no DEC × SEC interactions or SEC main effects for z-axis RMS or VDV during any transportation stage (P > 0.06). The bottom deck had a greater x,y-axis RMS than the top deck during all transportation stages (P < 0.01). The bottom deck had a greater x,y-axis VDV than the top deck during loading and transport (P < 0.03), but there was no difference (P = 0.52) during unloading. The bottom deck had a greater z-axis RMS and VDV than the top deck during loading and transport (P < 0.01), but there were no differences during unloading (P > 0.07). There were no SEC effects for x,y- and z-axis RMSs and VDVs during all transportation stages (P > 0.06). Acceleration values were compared with exposure action values (EAV; injury possible) and exposure limit values (ELV; injury likely) vibrations thresholds. Over the 5 observation days during all transport stages, a greater percentage of compartments violated both RMS and VDV thresholds in the x,y orientation (average 90%) than in the z orientation (average 76%). Overall, these data indicate that bottom decks experience greater three-axis vibrations than top decks in straight-deck trailers and that pigs on bottom decks may experience greater discomfort during transportation that could contribute to fatigue or the non-ambulatory condition.

Effects of driving style and bedding in pigs transported to slaughterhouse in different temperatures

“…Previous studies reported that vehicle vibration can be considered an acute stressor causing physiological and behavior stress in animals [ 28 , 29 ]. Vibration exposure of pigs was compared with ISO thresholds for exposure action value (injury potential) of 8.5 m s –1.75 for VDV [ 8 ]. Also, VDV over 9.1 m s –1.75 has been considered as aggressive by the European Union [ 30 ].…”

“…Poor driving techniques such as sudden acceleration, braking and cornering affect the ability of animals to maintain stable posture [ 7 ]. The vibration caused by vehicle motion during transportation leads to a displacement in a pig’s center of gravity to be displaced in vertical, lateral, and horizontal directions resulting in discomfort and motion sickness for pigs [ 8 ]. A previous study showed that a good driving style is essential so that their bodies remain in the correct position with stress reduced to the minimum [ 9 ].…”

Transport distance influenced the proportion of skin lesions in finishing pigs and negatively affected animal welfare

“…Many transport factors might induce stress in animals, such as distance and duration, microclimatic conditions, trailer design (Schwartzkopf-Genswein et al, 2012) and stocking density (Warriss et al, 1998;Pilcher et al, 2011), as well as the location inside the trailer (Barton Gade et al, 1996;, mixing of unfamiliar animals at loading (De jong et al, 2000;Barton Gade, 2008a and2008b), microclimatic conditions inside the trailer (Driessen, et al, 2020) loading/unloading systems (Faucitano & Goumon, 2018), trailer vibration (Stephens et al, 1985;Gebresenbet et al, 2011;Alambarrio et al, 2022).…”