Abstract: This study was aimed at evaluating the relationships between reproductive output and basal metabolic rate (BMR), energy budget and sustained metabolic rate (SusMR)during lactation in striped hamsters (Cricetulus barabensis) body mass, food intake, BMR, milk energy output (MEO) and body composition of the females, as well as litter size and litter mass were measured. Body mass decreased by 15.0 ± 0.8% throughout lactation, but food intake and gross energy intake increased significantly and the maxima were 13.9 ± 0.3 g / d and 222.1 ± 5.3 J/ d, respectively, which were 121% higher than during early lactation and 288% higher than in non-reproductive controls. MEO was 62.4 ± 2.3 kJ / d during peak lactation. BMR was 49.7 ± 1.1 kJ / d at weaning,and litter size and litter mass averaged 4.7 ± 0.2 and 50.5 ± 1.6 g. BMR was higher by 48% in the females during late lactation than early lactation. The correlation between BMR and the gastrointestinal tract was higher in lactating hamsters compared with controls. BMR was significantly positively related to litter size, litter mass,weight of mammary glands and MEO. It is suggested that the limitations on SusMR are set at a level of 4. 47 × BMR in first lactating hamsters. There might be a “trade-off in energy relocation”between BMR and reproductive output, i. e. the magnitude of increased BMR during late lactation was reduced by a decrease in body mass,which would be in favor of reproductive output.

Key words: Basal metabolic rate, Energy budget, Reproductive output, Striped hamster (Cricetulus barabensis)

摘要： 为了解黑线仓鼠繁殖输出与基础代谢率(BMR)的关系,阐明最大持续能量收支(SusMR)的限制水平, 揭示哺乳期能量收支对策,本文测定了哺乳期黑线仓鼠的体重、摄食量、BMR 和身体组成,以及哺乳期的胎仔数、胎仔重和泌乳能量支出(MEO)。结果显示,黑线仓鼠哺乳期体重降低了15.0 ± 0.8% , 摄食量显著增加, 哺乳高峰期平均摄食量为13.9 ± 0.3 g /d, 摄入能为222.1 ± 5.3 kJ/ d, 比哺乳初期增加121% , 比对照组高288% ;哺乳高峰期MEO 为62.4 ± 2.3 kJ/ d, 哺乳末期BMR 为49.7 ± 1.1 kJ/ d; 断乳时平均胎仔数4.7 ± 0.2、窝胎仔重50.5 ±1.6 g; 哺乳末期BMR 比对照组增加48% ,BMR 与消化系统各器官的相关性高于对照组; BMR 与胎仔数、胎仔重、乳腺重量和MEO 显著正相关。结果表明:初次繁殖的黑线仓鼠哺乳期SusMR 限制为4.47 ×BMR, 在自身维持和繁殖输出之间采取了“权衡分配”的原则,通过体重降低以减少BMR 的增加幅度, 从而有利于繁殖输出。

关键词: 黑线仓鼠, 繁殖输出, 能量收支, 基础代谢率