The cold temperature, a common environmental stress, reduces the immunity and re-production activities of the poultry. This study aims to investigate the role of acute and chronic cold exposure in the regulation of cyclooxygenase-2 (COX-2) and prostaglandin E synthase (PTGES) expression in the duodenum, jejunum, and ileum of quails. A total of 96 quails with 15 days of age were randomly allocated into 12 groups (8 each group) for exposure to acute (up to 12 h) and chronic (up to 20 days) cold temperature (12±1°C). After that, different segments of the intestine were harvested and subjected to morphology observations under the light and electronic microscopes. qRT-PCR was performed to analyze expression of COX-2 and PTGES, and DNA sequencing was performed to analyze PCR products. The data showed that under acute cold stress, expression of COX-2 and PTGES mRNA was first decreased and then increased in the duodenum, jejunum, and ileum of quails. However, chronic cold stress induced expression of COX-2 and PTGES mRNA in the duodenum, jejunum and ileum of quails, which was then reduced after 20 days of cold exposure. Morphologically, significant changes were also observed in the duodenum, jejunum and ileum after both acute and chronic cold stresses to the animals. The data from the current study indicated that both acute and chronic cold stresses were able to induce inflammation responses in the duodenum, jejunum and ileum, which might be due to the cold-damaged intestinal morphology.

Key words: Cold stress, Cyclooxygenase-2, Duodenum, Ileum, Jejunum, Prostaglandin E Synthase, Quail