Partitioning of metabolizable energy intake in sucking altricial and precocial rodent pups

Authors

  • M. Kam,

    1. Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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  • I. S. Khokhlova,

    1. Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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  • A. A. Degen

    1. Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Correspondence
Michael Kam, Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel. Tel/Fax: 972-8-6460674
Email: mkam@bgu.ac.il

Abstract

We partitioned the metabolizable energy intake (MEI) into energy for maintenance (MEm) and for growth (MEg) in sucking precocial and altricial rodent pups. Each of the two components includes energy loss due to the heat increment of feeding. MEm of precocial pups expressed as average daily energy costs or as a proportion of MEI was greater than in altricial pups of similar size and, therefore, less energy was available for growth. Consequently, the overall energy cost (via total MEI) per unit postnatal growth of precocial pups was greater than for altricial pups of similar size. We used the proportion of calculated MEm to that predicted by body mass as an index of precociality in rodent pups. The proportion of MEg to MEI in precocial pups was lower than in altricial pups and was inversely related to the index of precociality.

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