Voluntary exercise at the expense of reproductive success in Djungarian hamsters (Phodopus sungorus).
Summary of "Voluntary exercise at the expense of reproductive success in Djungarian hamsters (Phodopus sungorus)."
Energy demands of gestation and lactation represent a severe challenge for small mammals. Therefore, additional energetic burdens may compromise successful breeding. In small rodents, food restriction, cold exposure (also in combination) and wheel running to obtain food have been shown to diminish reproductive outcome. Although exhibited responses such as lower incidence of pregnancy, extended lactation periods and maternal infanticide were species dependent, their common function is to adjust energetic costs to the metabolic state reflecting the trade-off between maternal investment and self-maintenance. In the present study, we sought to examine whether voluntary exercise affects reproduction in Djungarian hamsters (Phodopus sungorus), which are known for their high motivation to run in a wheel. Voluntary exercise resulted in two different effects on reproduction; in addition to increased infanticide and cannibalism, which was evident across all experiments, the results of one experiment provided evidence that free access to a running wheel may prevent successful pregnancy. It seems likely that the impact of voluntary wheel running on reproduction was associated with a reduction of internal energy resources evoked by extensive exercise. Since the hamsters were neither food-restricted nor forced to run in the present study, an energetic deficit as reason for infanticide in exercising dams would emphasise the particularly high motivation to run in a wheel.
Institute of Zoology, University of Veterinary Medicine Hannover, Buenteweg 17, 30559, Hannover, Germany, email@example.com.
This article was published in the following journal.
Name: Die Naturwissenschaften
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/20676598
- DOI: http://dx.doi.org/10.1007/s00114-010-0701-z
Medical and Biotech [MESH] Definitions
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
A genus of hamsters characterized by small size, very short tail, and short, broad feet with hairy soles.
Success in bringing an effort to the desired end; the degree or level of success attained in some specified area (esp. scholastic) or in general.
The exercise capacity of an individual as measured by endurance (maximal exercise duration and/or maximal attained work load) during an EXERCISE TEST.
Controlled physical activity, more strenuous than at rest, which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used. The intensity of exercise is often graded, using criteria such as rate of work done, oxygen consumption, and heart rate.
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