剃毛对大绒鼠持续能量摄入的影响

Effect of Shaving on Sustainable Energy Intake in Eothenomys miletus

持续能量摄入(Sus EI)的上限对于哺乳期母体的生存非常重要。先前的研究表明大绒鼠Eothenomys miletus Sus EI的限制可能受到外周限制假说,而不支持热散失假说。为了再次验证这2个假说,本研究在哺乳早期对大绒鼠剃毛,测定剃毛组和对照组的体质量、食物摄入量、静止代谢率、胎仔数、胎仔质量和泌乳输出。结果表明:剃毛可以显著增加大绒鼠的食物摄入量和静止代谢率,但是对于胎仔数和泌乳输出没有影响。所有结果不支持热散失假说,而支持外周限制假说,说明大绒鼠在哺乳期的Sus EI可能受到乳腺泌乳能力的限制。暗示在泌乳高峰期Sus EI的限制在不同物种间的反应可能是不一样的。

The limits to sustainable energy intake（ SusEI） are very important to the mammals＇ survival during lactation.Previous studies suggested that the Sus EI limitation of Eothenomys miletus may be constrained by peripheral limitation hypothesis instead of heat dissipation limitation hypothesis. To distinguish the two ideas,E. miletus were shaved at early lactation,followed by multiple examination of body mass,food intake,resting metabolic rate（ RMR）,litter size and mass,and milk energy output（ MEO） among the shaved mothers and non-shaved controls. The results showed that shaving could significantly increase food intake and RMR,but had no significant effects on litter mass and MEO. These data supported the peripheral limitation hypothesis rather than the heat dissipation limitation hypothesis,indicating that Sus EI was more likely peripherally caused by the capacity of mammary gland to produce milk. The inconsistent responses to sustainable limits suggested that the limitations on Sus EI during peak lactation might be differed in all species.