... supplementary thyroid hormones (THs) or the inhibitor methimazole during lactation at 21 or 32.5°C, and measured food intake, resting metabolic rate (RMR), milk energy output (MEO), serum THs and mammary gland gene expression of females, and litter size and mass of their offspring. Lactating females developed...

... rodents compensate with larger litters than low altitude (LA) conspecifics. Rodent mothers are the sole source of heat and nutrition for altricial offspring and lactation is energetically costly. Thus, it is unclear how HA females balance energy allocation during the nursing period. We hypothesized...

...Guang-Min Deng; Jing-Xin Yu; Jia-Qi Xu; Yu-Fan Bao; Qian Chen; Jing Cao; Zhi-Jun Zhao ABSTRACT High temperatures and heatwaves are rapidly emerging as an important threat to many aspects of physiology and behavior in females during lactation. The body's capacity to dissipate heat is reduced by high...

...Meng-Huan Bao; Li-Bing Chen; Catherine Hambly; John R. Speakman; Zhi-Jun Zhao ABSTRACT Exposure to high temperatures (heatwaves) is rapidly emerging as an important issue of climate change, in particular for female mammals during lactation. High temperatures adversely affect the ability...

... or reduced litter size in mice during their first lactation, and then followed them through a successive unmanipulated lactation. Measurements of food intake, body mass, milk energy output (MEO), litter size and litter mass were taken. Offspring from the first lactation were also bred to investigate...

...Jing Wen; Song Tan; Qing-Gang Qiao; Wei-Jia Fan; Yi-Xin Huang; Jing Cao; Jin-Song Liu; Zuo-Xin Wang; Zhi-Jun Zhao ABSTRACT Limits to sustained energy intake (SusEI) during lactation are important because they provide an upper boundary below which females must trade off competing physiological...

... to disproportionately high rates of mortality at the end of lactation in this species. To examine and quantify metabolic changes associated with reproduction, we measured the resting metabolic rate (RMR) of a female sea otter across gestation, lactation and non-reproductive periods. Concurrently, measurements were made...

...Ji-Ying Zhang; Xiao-Ya Zhao; Jing Wen; Song Tan; Zhi-Jun Zhao ABSTRACT In small mammals, marked phenotypic plasticity of digestive physiology has been shown to make it easier for them to cope with energetically stressful periods, such as lactation. It has been proposed that the capacity of the gut...

..., their metabolisable energy intake significantly increased over the first 13 days of lactation and then reached a plateau. At peak lactation, MH mice assimilated on average 45.3% more energy than ML mice (222.9±7.1 and 153.4±12.5 kJ day −1 , N =49 and 24, respectively). Moreover, MH mice exported on average 62.3 kJ...

... financial interests. 17 11 2013 8 1 2014 © 2014. Published by The Company of Biologists Ltd 2014 Oxidative stress Cost of reproduction Basal metabolic rate Lactation Artificial selection The evolution of high basal metabolic rate (BMR) and endothermy are hypothesized...

...Elizabeth M. Dlugosz; Cynthia J. Downs; Irina S. Khokhlova; A. Allan Degen; Boris R. Krasnov Reproduction is an energy-demanding activity in mammalian females, with increased energy requirements during pregnancy and, especially, during lactation. To better understand the interactions between...

... in lactating compared with non-reproductive gerbils. These changes were in line with the selective resource allocation predictions. However, the phytohaemagglutinin response and serum total immunoglobulin (IgG) were not suppressed, and other markers of oxidative damage [malondialdehyde (MDA) (TBARS...

...Deng-Bao Yang; Li Li; Lu-Ping Wang; Qing-Sheng Chi; Catherine Hambly; De-Hua Wang; John R. Speakman SUMMARY We evaluated factors limiting lactating Mongolian gerbils ( Meriones unguiculatus ) at three temperatures (10, 21 and 30°C). Energy intake and daily energy expenditure (DEE) increased...

... and the rest came from one unrelated female (i.e. fostered pups). Food intake increased linearly during early lactation and reached a plateau during late lactation (day 9–13, called the asymptotic food intake, FI AS , equivalent to SusEI). Parent–offspring regression showed that FI AS , MEO and litter mass...

...Osei A. Duah; Kweku A. Monney; Catherine Hambly; Elzbieta Król; John R. Speakman SUMMARY Several studies have suggested that lactation performance may be programmed by the number of fetuses during pregnancy, whereas other studies indicate that processes during lactation are more important...

... number of secretory cells in the gland, its potential effect on the structural development of lobulo-alveolar tissues has not been directly investigated. To examine whether reproductive experience affects lobulo-alveolar development, we took mammary gland biopsies at early and peak lactation from...

...Elzbieta Król; Samuel A. M. Martin; Ilpo T. Huhtaniemi; Alex Douglas; John R. Speakman SUMMARY It has been proposed that the performance of lactating animals is limited by the capacity of the female to dissipate body heat – the heat dissipation limit (HDL) theory. This theory predicts that milk...

...Jian-Guo Cui; Gang-Bing Tang; De-Hua Wang SUMMARY Both pregnancy and lactation are associated with hyperphagia, and circulating leptin levels are elevated during pregnancy but decreased during lactation in Brandt's voles, Lasiopodomys brandtii . Previous findings suggest that impaired leptin...

...Zhi-Jun Zhao The combination of two stressors, lactation and cold, is suggested to be an excellent model for testing the factors limiting sustained energy intake (SusEI). Limits to SusEI during peak lactation may be imposed peripherally by the capacity of mammary glands to produce milk or may...

... – the ‘central limitation’ hypothesis. Experimental evidence from lactating mice exposed to different ambient temperatures allows us to reject this and similar ideas. Two alternative ideas have been proposed. The ‘peripheral limitation’ hypothesis suggests that the maximal sustained energy intake reflects...