RESUMO
In order to assess the effects of chitosan supplementation on immune function, antioxidant enzyme activities and histological changes in Leiothrix lutea exposed to acute heat stress, 80 healthy adult birds were randomly divided into five experimental groups. The normal-temperature group (NTG) was maintained at 21°C and fed the basic diet. The treatment groups were fed the basic diet supplemented with 0%, 0.1%, 0.5% and 1.0% chitosan, respectively, in normal-temperature environment for 30 days and then exposed to heat (35°C and 40% relative humidity) for 3 hr. The results showed that the immune function and anti-oxidative enzyme activities in L. lutea in heat-stressed environment were enhanced by chitosan supplementation, whereas oxidative damage of tissues and cells were alleviated. The results revealed that addition of 0.5% chitosan to the diet may be optimal, playing a key role in meeting the demands of captive-bred L. lutea in high-temperature environments. This may constitute a useful feeding strategy in accordance with the behavioural selection of wild L. lutea, and could effectively promote ex situ conservation.