Digestive Responses of Birds to Increased Demand for Food

9318675 Karasov：某些鸟类在迁徙前的育肥期、冬季低温期和产后生长期间的摄食和消化率特别高。PI将研究鸟类肠道如何适应高摄食率，因为这很重要，但研究很少。这些调整很重要，因为它们可能会影响迁徙期间的停留时间、鸟类的冬季分布以及生长和发育模式的演变。对鸟类肠道调节的研究也将补充具有生物医学意义的哺乳动物的类似研究。最后，对消化能力和限制的了解应该有助于为圈养动物设计人工饲料，从而改善动物园濒危物种和有经济价值动物的饲养实践。该项目将研究几种鸟类在迁徙、寒冷适应和出生后生长过程中对高摄食率的胃肠调节。PI将检测食糜滞留时间、胃肠道组织数量、组织特异性消化酶水平和营养吸收的变化。选择这些特征是因为它们决定了全动物营养性能的特征，如消化效率和消化率。＊＊＊

9318675 Karasov Feeding and digestion rates of some birds are particularly high during fattening prior to migration, during wintertime exposure to low temperature, and during postnatal growth. The PI will study how the avian gut adjusts to high feeding rate because it is important and has been little studied. The adjustments are important because they might influence stop-over times during migration, wintertime distribution of birds, and the evolution of growth and development patterns. Study of the gut adjustments of birds will also complement similar kinds of studies in mammals that have biomedical significance. Finally, knowledge of digestive capabilities and limitations should help in the design of artificial diets for animals in captivity, and hence improve husbandry practices for both endangered species in zoological parks and animals with economic value. The PI will study gastrointestinal adjustments to high feeding rate in several avian species during migration, cold acclimation, and postnatal growth. The PI will test for changes in digesta retention time, amount of gastrointestinal tissue, and tissue-specific levels of digestive enzymes and nutrient absorption. These features are chosen because they determine features of whole-animal nutritional performance such as digestive efficiency and rate. ***