Thermal Micro-Environment during Poultry Transportation in South Central United States

Abstract

Simple SummaryThis project monitored the internal micro-environments of live poultry transport trailers during loading and transport. For the 28 trips evaluated, trailers were modified using common USA industry mitigation practices designed to optimize bird comfort under a wide range of environmental conditions. In the cold season, double boarding of the exterior area of the transport modules elevated the internal temperature more than 8 °C above ambient temperatures as low as −16 °C. However, the temperature elevation may not be sufficient when ambient temperature was below 0 °C. In the warm season, surface wetting of birds and evaporative cooling applied during on-farm loading maintained trailer thermal conditions at or below ambient temperature for part of the road transport. However, this study suggests that additional improvement in equipment design or management is warranted when temperatures are extremely cold or hot.AbstractThis observational study was conducted to characterize the thermal micro- climate that broilers experienced in commercial poultry transporters under various weather conditions and typical management practices in the South Central USA. We continuously monitored temperature and relative humidity in 45 interior locations of 28 fully-loaded commercial trailers over 2 year spans from 2015–2016 in South Central USA. In the cold season, double boarding of the exterior area of the transport modules maintained temperatures at least 8 °C warmer than ambient temperatures as low as −16 °C. Overall, temperature at all locations decreased as transporters traveled from farms to processing plants during winter trips with double boards. In the hot season, assistance by evaporative cooling during on-farm loading resulted in interior temperatures within ± 2 °C of ambient conditions (up to 36 °C) during road transport. In the summer months, trailers uniformly gained 2 °C as vehicles travelled for 45 min from farms to plants. Apparent equivalent temperatures of the monitored summer trips averaged 80.5 °C, indicating possible heat stress conditions based on the thermal comfort zones defined by literature index values. For longer trips, cooling assistance on the farms may be insufficient to prevent temperatures from rising further into extremely hot conditions in the transporters, leading to a dangerous thermal environment.

Comparison of the Automatic and Manual Broiler Pre-Slaughter Chain Based on Trailer Microclimate during Transportation and Its Effect on m. pectoralis major

“…Under optimal conditions, broilers should be exposed to a temperature in the so-called thermoneutral zone during transport. The results of our study do confirm previous research by Webster et al [27], in which the optimal thermal zone is 8-18 • C. In contrast to the earlier findings of Meltzer [28], these results suggest an optimal thermal zone from 24 to 28.5 • C. Temperature fluctuations and relative humidity may be a particular problem causing higher mortality and frequent injuries of transported broilers [7,9,[29][30][31].…”

“…The climatic conditions in crates and trailers are frequently overlooked while transporting poultry [8]. Poor welfare quality related to morbid conditions during transportation, caused by the thermal environment and pressure of transportation (air movement, low ambient temperature, and winter precipitation) and the decline in meat quality of slaughtered birds, cause big economic losses [9,10]. Stressful events (as well as interactions between animals and humans) trigger reactions in animals that translate into physical, physiological, and behavioral stress [10,11].…”

Post‐mortem indications of poor welfare—an hypothesis upon supine broilers: stress and efforts to ameliorate suffering in a low throughput abattoir

“…The use of water misting in hot climates is the main heat stress treatment, welfare aid, and DOA control method. Jiang and others,18 Xing and others16 and Aldridge and others19 in China and the USA employed water misting to control heat stress and reduce or avoid PSE broiler pectorals.…”

Influence of Long-Distance Transportation Under Various Crating Densities on Broiler Meat Quality During Hot and Humid Weather

“…Global warming is severely affecting the climatic conditions particularly of developing countries such as Pakistan by widening the gap between winter and summer temperatures ( Abbas, 2013 ). High ambient temperature coupled with high humidity not only reduces growth performance but also threatens the well-being of broilers during their journey towards abattoirs ( Aldridge et al , 2019 ). Temperature and humidity variations during transportation can cause high mortalities ( Arikan et al , 2017 ), oxidative damage to muscles ( Estévez, 2015 ), and can also reduce physical appearance and functional characteristics of meat by inducing protein denaturation, pale color, and drip loss ( Wilhelm and Maganhini, 2010 ; Xing et al , 2015 ).…”