The Effects of 24h Water Deprivation when Associated with Some Aspects of Transportation on the Behaviour and Blood Chemistry of Sheep

When sheep are transported they are potentially exposed to a number of factors, including water and feed deprivation, low space allowance and elevated environmental temperature, that are not related to vehicle motion but could result in animal welfare problems, either on their own or in combination. In a 2x2 factorial experiment, groups of sheep (n = 6) 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 041m2 sheep−1 without feed. After 24h 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. This suggests 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.