The effect of road and sea transport on inflammatory, adrenocortical, metabolic and behavioural responses of weanling heifers

At the end of the grazing season, 60 Charolais × beef heifers (mean live weight 245, s.e. 4.3 kg and mean weaning age 219, s.e. 4.9 days) were abruptly weaned from their dams on day 0. The animals were assigned by live weight to two treatments, transport (T) (n = 40) (mean 246, s.e. 5.4 kg) and control (C) (n = 20) (mean 247, s.e. 7.2 kg) on day 0. The T animals were transported from Ireland to France on a roll-on roll-off ferry at a stocking density of 0.93 m2/animal and then by road for 9 h to a French lairage while C animals remained in Ireland and were not transported. On arrival at the French lairage (d 2), 20 T animals were unloaded (ULT) and rested for 12 h in the French lairage and 20 animals rested (RT) on the transporter. All animals had access to hay and water. After the rest period, the ULT animals were re-loaded. The subsequent journey by road from France to Spain was 9 h travel, 7 h rest (on the transporter) and a further 7 h travel by road. All T animals were blood sampled prior to transport (day (d) 0; baseline), on arrival in the French lairage (d 2), after 12 h rest in the French lairage (d 2), on arrival at the feedlot in Spain (d 4) and on d 6, d 8, d 10 and d 34. Control animals were blood sampled at the same times as T animals.ULT and RT animals had lower (P < 0.05) live weight than C animals on d 6. WBC number was lower (P < 0.05) in control animals on d 10 and greater on d 34 compared with baseline values. RT and ULT animals had greater (P < 0.05) WBC number than baseline on d 2 (arrival in France) to d 34. Neutrophil % was unchanged in RT, ULT and control animals compared with baseline. Control, RT and ULT animals had lower haematocrit % (P < 0.05) throughout the study compared with d 0. There was no difference (P > 0.05) in plasma protein concentration between RT and ULT animals from day 2 to d 34. Plasma concentrations of urea were higher (P < 0.05) in RT animals from d 2 to d 34 compared with C animals. RT and ULT animals had lower (P < 0