高纤维食物对黑线仓鼠哺乳期能量收支的影响OA北大核心CSTPCD

Reproduction period is one of the most important stages of life history in small mammals,during which the maternal energy requirements are maximized in lactation.To meet the energy requirements of their offspring,mothers usually increase energy intake to a ceiling,i.e.the maximal sustained energy intake(mSusEI).The notable plasticity of the digestive morphology and function is important for a variety of animals to cope with the changes in energy require-ments.However,so far it is unclear if the mSusEI during peak lactation is constrained by the digestive system.In the present study,body mass,food intake,gross energy intake,digestibility,resting metabolic rate,and milk energy output,as well as the mass of gastrointestinal tracts and the digestive enzymes activity of the small intestine were examined in striped hamsters(Cricetulus barabensis)that were fed with high-fiber diet during lactation.The maternal energy intake and reproductive output were analyzed in the hamsters raising different litter sizes.The activity of digestive enzymes was also compared in the hamsters raising small,medium,and large litter sizes under the high-fiber diet feeding.The re-sults showed that the energy budgets of the hamsters during lactation were correlated with litter size.The mSusEI was not significantly affected by high-fiber diet.The hamsters fed with high-fiber diet decreased digestive energy intake and digestibility significantly,but did not change their gross energy intake,compared to those fed with low-fiber control diet.The milk energy output was significantly decreased in the hamsters fed with high-fiber diet,which could not meet the en-ergy requirements of offspring,resulting in decreased growth rate during the lactation period.The masses of stomach,small intestine,large intestine and caecum,as well as the activity of amylase,maltase and aminopeptidase of the small in-testine were significantly higher in the hamsters fed with high-fiber diet than those fed with low-fiber control diet,while neither tract mass nor digestive enzyme activity was significantly affected by litter size.These data indicate that the mSusEI at peak lactation is constrained by the digestive system,providing support for the central limitation hypothesis.Based on the central limits to the mSusEI at peak lactation,the increases of fiber content in diet may decrease reproduc-tive value.