Limits to sustained energy intake. XXVII. Trade-offs between first and second litters in lactating mice support the ecological context hypothesis

Lobke M. Vaanholt, Osei A. Duah, Suzanna Balduci, Sharon E. Mitchell, Catherine Hambly, John R. Speakman
  • Journal of Experimental Biology, January 2018, The Company of Biologists
  • DOI: 10.1242/jeb.170902

Investment by female mice in their first lactation impacts investment in the next lactation.

What is it about?

During lactation female mice increase their energy intake by about a factor of five over when they are not breeding. However after the initial increase in early lactation the intake reaches a plateau suggesting intake is limited. We have been interested in what imposes this limit. One idea is that the intake at peak lactation isn't limited but females choose how much to invest based on a trade off with their subsequent lactation performance. In this paper we manipulated how much females invested in litter number 1 and looked at how much they then invested in litter number 2. We found that there was indeed a trade ff between litters. In principle then the limit might not be a rigid physiological limit but part of a female investment strategy responsive to ecological context.

Why is it important?

Limits on maximal intake are important to understand because these limits impose constraints on performance in all sorts of different spheres - particularly reproduction.

Perspectives

Professor John Speakman

Showing that there is a trade off indicates that in principle the limit we observe in lactation 1 may be part of an allocation strategy. It is important to note however that it is consistent with such a strategy but that doesn't mean that it definitely is the result of such a strategy. That demonstration requires much more work.

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http://dx.doi.org/10.1242/jeb.170902

The following have contributed to this page: Professor John Speakman