Limits to sustained energy intake II. Inter-relationships between resting metabolic rate, life-history traits and morphology in Mus musculus
Year: 2001
Type: article
Abstract: Late lactation is the most energetically demanding time for a female mammal (Millar, 1977;Gittleman and Thompson, 1988;Kenagy et al., 1990;Forsum et al., 1992;Thompson, 1992;Speakman and McQueenie, 1996).Sustained energy intake during late lactation has been suggested to be limited (Hammond and Diamond, 1992;Hammond and Diamond, 1994;Hammond and Diamond, 1997;Hammond et al., 1996;Speakman and McQueenie, 1996) at around seven times resting metabolic rate (RMR) (Kirkwood, 1983;Peterson et al., 1990;Hammond and Diamond, 1997), which has consequences for the size and mass of litters produced.As litter size increases, there is a decrease in the mean mass of individual pups (Meyer et al., 1985;König et al., 1988;Hammond and Diamond, 1992;Kam and Degen, 1994;Rogowitz, 1996;Rogowitz, 1998), indicating that the female may be unable to supply larger litters with more energy.The MF1 strain of mouse has been shown to reach a plateau of food intake during late lactation and over litter sizes of 9-15 pups (Johnson et al., 2001a), suggesting that the females are not able to supply sufficient energy for pups of larger litters to wean at the same size as those from smaller litters, possibly because of limits in their capacity to ingest more food or to supply more milk.Many rodents have a postpartum oestrus (Bateman, 1957;Asdell, 1964) and can therefore conceive on the day after parturition, but thereafter not until the litter is weaned.These animals become pregnant whilst lactating.An advantage of mating during a postpartum oestrus is that there is a shorter inter-1947
Authors: Johnson, M S, Thomson, S C, Speakman, J R
Institution: University of Aberdeen
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7073863315