Effect of loading practices and 6-hour road transport on the physiological responses of yearling cattle

Abstract

A controlled study using 16 yearling Angus steers was conducted to determine the physiological responses associated with loading practices followed by 6 h of road transport and 17 h of post-transport recovery. The cattle were quietly mustered from grazing at pasture and directly loaded onto a truck for transport. During loading, cattle received either four consecutive prods with a commercial electric prodder (n = 8) or no prodding (control, n = 8). The experiment was performed in four replicates, conducted on consecutive days, with four animals (n = 2 per treatment) utilised on each day. On the truck, cattle were confined to pens that each held a single animal facing the direction of travel. Blood samples were taken via jugular catheters before and during the 6 h journey and during the 17 h recovery phase. Samples were analysed for haematology, osmolality and plasma cortisol, total protein, creatine kinase, blood urea nitrogen and the acute phase protein haptoglobin. The physiological measurements indicated that most stress occurred during loading and the initial stages of transport, but after this, the cattle habituated and were able to cope with the 6 h of transport. After 17 h of recovery, nearly all the variables measured had returned to their pre-transport levels. Use of an electric prodder during loading did not modify the physiological responses to loading, transport or the rate of recovery compared with the controls.