Limits to sustained energy intake. XXIX. The case of the golden hamster (Mesocricetus auratus) [RESEARCH ARTICLE]

Sarah A. Ohrnberger, Catherine Hambly, John R. Speakman, and Teresa G. Valencak Golden hamster females have the shortest known gestation period among placental mammals, and at the same time raise very large litters of up to 16 offspring, which are born in a naked and blind state and are only able to pick up food from days 12 to 14 onwards. We quantified energy metabolism and milk production in female golden hamsters raising offspring under cold (8°C), normal (22°C) and hot (30°C) ambient temperature conditions. We monitored energy intake, subcutaneous body temperature, daily energy expenditure, litter size and pup masses over the course of lactation. Our results show that, in line with the concept of heat dissipation limitation, female golden hamsters had the largest energy intake under the coldest conditions and a significantly lower intake at 30°C (partial for influence of ambient temperature: F2,403=5.6; P=0.004). Metabolisable energy intake as well as milk energy output showed the same pattern and were significantly different between the temperatures (partial for milk energy production: F1,40=86.4; P<0.0001), with consistently higher subcutaneous temperatures in the reproductive females (F1,813=36.77; P<0.0001) compared with baseline females. These data suggest that raising offspring in golden hamsters comes at the cost of producing large amounts of body heat up to a level constraining energy intake, similar to that observed in some laboratory mice....
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research