A 2 × 2 factorial completely randomized design was conducted to study the effects of Pandanus
amaryllifolius Roxb. supplementation under two types of housing system on the egg production
performance and egg quality of laying hens. Three hundred-twenty Hisex Brown layers aged about 25
weeks were randomly divided into four groups each with eight replications. The animals in each replicate
were randomly fed with a laying-hen diet supplemented with either 0 or 5 g per hen per day of fresh P.
amaryllifolius Roxb. and were kept in an evaporative cooling house versus in an open house. The daily
egg production was collected over four periods with 28 d per period and the eggs from the last 3 d in
each period were collected to measure egg quality. The results showed that the egg production, daily
feed intake and egg quality, in terms of egg weight and eggshell thickness, of laying hens kept in the
evaporative cooling house were significantly better than those of hens raised under the open house
system (P< 0.01). Nevertheless, supplementation with P. amaryllifolius Roxb. in the diet significantly
improved the egg production (P< 0.01), whereas the daily feed intake of the hens was also likely to be
increased (P = 0.06). The egg production of laying hens kept in the open house system could be improved
by about 11% through the supplementation with 5 g per hen per day of P. amaryllifolius Roxb. in the
diet, which had no significant effect on the egg production of hens kept in the evaporative cooling house.
Key words: layer diet, Pandanus amaryllifolius Roxb., closed house, open house, evaporative cooling