Digestive Responses of Birds to Increased Demand for Food

9318675一些鸟类在迁徙前的育肥期间、冬季暴露在低温下和出生后生长期间的卡拉索夫喂食率和消化率特别高。PI将研究禽类肠道如何适应高摄食率，因为这很重要，而且研究很少。这些调整很重要，因为它们可能会影响迁徙期间的中途停留时间、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，对消化能力和局限性的了解应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具有经济价值的动物的饲养实践。PI将研究几种鸟类在迁徙、冷驯化和出生后生长过程中对高摄食率的胃肠调节。PI将测试消化保留时间、胃肠道组织数量以及特定组织消化酶和营养吸收水平的变化。之所以选择这些特征，是因为它们决定了整个动物的营养表现特征，如消化效率和消化速率。***

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. ***