Background: Small intestine and peripheral organs are the main organs for digestion and absorption in the gastrointestinal tract. OBJECTIVES: To investigate effects of different levels of Vitamin E and Selenium on growth performance and small intestine morphometry in Japanese quail. METHODS: A total of 405 mixed sex Japanese quails were randomly allocated into 9 experimental groups by 3×3 facto...

Estimates of cell volume in fossilized bones of extinct dinosaurs indicate that genome size underwent a significant reduction in the early theropods, from which birds later evolved. This suggests that birds' small genomes are not an adaptation to metabolic demands associated with flight.

Homing pigeons were equipped with a pair of small coils around their heads. Birds with an induced field of 0.6 gauss and the south magnetic pole up, oriented toward home normally under both sun and overcast. Birds with the polarity reversed oriented toward home when the sun was visible but often flew away from home under overcast.

Seasonal phenotypic flexibility in small birds produces a winter phenotype with elevated maximum cold-induced metabolic rates (=summit metabolism, Msum). Temperature and photoperiod are candidates for drivers of seasonal phenotypes, but their relative impacts on metabolic variation are unknown. We examined photoperiod and temperature effects on Msum, muscle masses and activities of key cataboli...