The effects of 24 h water deprivation when associated with some aspects of transportation on the behaviour and blood chemistry of sheep

In a 2×2 factorial experiment, groups of 6 sheep were moved from individual pens where they had access to hay and water to environmental chambers kept at either 14°C or 21°C. Within each chamber, half the sheep had access to water but they were all kept at a space allowance of 0.41 m²/sheep without feed. After 24 h they were returned to their individual pens and offered hay and water. Behaviour and a range of biochemical measurements of dehydration and feed restriction were recorded before, during and after the treatment period. During the treatment period there was no evidence of dehydration, and sheep with access to water drank less than they did before the treatment. The plasma concentration of free fatty acids increased during fasting and, post-treatment, the intake of hay was greater than before treatment. The rapid post-treatment intake of dry feed was associated with some evidence of dehydration, as indicated by increased plasma osmolality and plasma vasopressin concentration. It is suggested that following provision and consumption of large quantities of feed after a period without access to feed and water during transportation, sheep must be allowed sufficient time to drink before a subsequent journey is undertaken.