Seasonal metabolic factors may be responsible for deaths in sheep exported by sea

Metabolic responses to persistent inappetance were studied in sheep transported by sea from Australia to the Arabian Gulf in May and August. In the May voyage inappetant sheep successfully mobilised fat and generated ketones to supply energy and few died (0.83%). However, in August, inappetant sheep failed to mobilise fat for more than a few days and the death rate was much higher (3.27%). The causes of death were similar in both voyages; approximately 65% of the deaths were due to inanition. We postulated that in May, sheep coming from dry pastures were nearing the end of a cycle of liveweight loss and were metabolically adjusted to using adipose reserves for energy. However, in August, sheep had entered a period of liveweight gain on green pastures and were consequently unable to sustain lipolysis for energy supply when inappetant.