Heat produced by broiler chickens in a commercial transport vehicle

Calorimetric measurements have been made for broiler chickens in a commerci al transport vehicle. A standard poultry transport vehicle, which consisted of a lorry and drawbar trailer combination, was equipped with ventilating fans and the air movement restricted to a single inlet and single outlet ar rangement on each of the two elements of the vehicle. Measurements of tempe rature, relative humidity and the concentration of carbon dioxide (CO2) wer e made at the inlets and outlets for a known set ventilation rate. For the calorimetry, the fully laden vehicle was held stationary for a period of 2 h prior to the birds being unloaded into lairage. The measurements showed t hat there was a significant period before heat production stabilized, parti cularly, on the lorry, where conditions during transport were not controlle d. The inadequacy of natural ventilation on the trailer required fan ventil ation to operate at all times and hence conditions on the trailer were more stable. Once stability had been reached, the sensible and latent heat prod uction were measured, together with the CO2 production. The calculated resp iratory quotient was consistent with values derived elsewhere for adult fow l in a fasted condition. A minimum design ventilation rate based on livewei ght is proposed subject to uniformity of ventilation throughout the vehicle . (C) 2000 Silsoe Research Institute.