Abstract: The objective of this study was to determine the park energy assimilation capacity by cold induction in Brandt’s vole (Microtus brandti). Maximum assimilation energy was measured by two cold-induction procedures: group I was lowered temperatures gradually from 23℃ to –6℃; and group II was directly exposed to cold temperatures 5℃ and 0℃. The assimilation energy was increased with the decreasing in temperature, kept stable from 5℃, and reached the park (3.37 kJ/g•d) at 0℃in the group I. The maximum assimilation energy in group II was 2.39 kJ/g•d, The maximum assimilation energy in two group was 1.8-2.5 BMR (basal metabolic rate,1.35 kJ/g•d ),suggesting that the actual energy budgets of Brandt’s vole in their natural environment keep fairy near to the upper physiological limit. Our results indicate that the limitation for energy budgets in Brandt’s vole is consistent with the central limitation model.

Key words: Maximum energy assimilation, Brandt's vole(Microtus brandti), Digestibility, Inner Mongolia grassland

摘要： 利用低温诱导，以食物平衡法对内蒙古草原布氏田鼠的最大同化能进行了测定：实验分为两组．一组为逐渐降温，温度梯度依次为：23℃、l5℃、l0℃、5℃、0℃、–3℃和–6℃。结果显示动物的同化能5℃后基本维持不变．0℃达峰值，为3.37±0.33 kJ/g·d。另一组动物则直接进5℃和℃测定同化能，在0℃时测得突然降温组最大同化能为2.39±0,22 kJ/g·d 布氏田鼠的基础代谢率(Basal metabolic rate, BMR)为2.796±0.209 ml O₂/g·h (1.35±0.10 kJ／g·d)。两种方式诱导的最大同化能是基础代谢率的1.8～2.5倍，在所有已测定的哺乳动物的最大同化能范围之内，表明布氏田鼠在自然状态下可能长期保持其实际能量收支接近其生理极限。本文的结果支持中心限制假说。

关键词: 最大同化能, 布氏田鼠, 消化率, 内蒙古草原