中文摘要：

体重可影响动物几乎所有的生物学变量。高体重双亲通常产生较大胎仔数。繁殖过程代价很高,可能伴随着氧化损伤。为比较双亲体重对繁殖期能量学特征、繁殖输出和氧化损伤的影响,检测了高体重组（雌性：51.5 g±1.6 g;雄性：60.4 g±2.5 g）和低体重组（雌性：35.5 g±1.2 g;雄性：49.6 g±2.8 g）布氏田鼠繁殖过程中母体的体重和摄食量,分娩时的胎仔数和胎仔总重,及后代断乳时母体的身体成分、激素含量（血清瘦素和催乳素）和氧化损伤（血清丙二醛、蛋白质羰基和肝脏丙二醛含量）。结果显示：（1）高体重组妊娠末期的母体体重增量显著高于低体重组;（2）高体重组母体的出生胎仔数显著高于低体重组,但出生及断乳时的平均胎仔重、胎仔总重和母体繁殖期间的能量摄入无显著差异;（3）血清激素含量、身体成分、身体脂肪重量及氧化损伤指标均无组间差异。结果表明,高体重布氏田鼠可产生较多的出生胎仔数,但母体并不通过摄入更多的能量来保证其繁殖输出,对氧化损伤也没有影响。这些结果对于理解不同体重的动物在繁殖期间的能量策略以及繁殖与生存之间的权衡等生活史理论具有重要意义。

英文摘要：

Body mass can affect almost all biological variables of animals. Parents with high body mass usually have large litter sizes. As a costly physiological process,reproduction is often accompanied by oxidative damage. The present study was designed to explore the effects of parental body mass on life history characteristics,reproductive output and oxidative damage. Adult Brandt’s voles（ Lasiopodomys brandtii） were divided into two groups： high（ HBM： female,51. 5 g ±1. 6 g; male,60. 4 g ± 2. 5 g） and low body mass（ LBM： female,35. 5 g ± 1. 2 g; male,49. 6 g ± 2. 8 g）. Parental body mass and energy intake during reproduction,litter size,litter mass,body composition,serum hormones（ leptin and prolactin）,and oxidative damage parameters（ serum protein carbonyl,serum and liver MDA levels） were measured. The results showed：（ 1） At the end of pregnancy,the body mass gain in the HBM group was significantly greater than that of the LBM group.（ 2） Litter size at birth in the HBM group was significantly greater than that of the LBM group,but there were no significant differences in pup mass,litter mass at birth or weaning and maternal energy intake during reproduction between the HBM and LBM groups.（ 3） No significant differences in serum leptin and prolactin,body composition,body fat,serum protein carbonyl,serum and liver MDA levels were detected between these two groups. These results suggested that Brandt’s voles with HBM give birth to more pups,but the mothers do not increase energy intake to support the added reproductive output. Thus,the parental body mass can affect the litter size at birth,but has no effect on reproductive output and oxidative damage. These findings are important for understanding energy strategies during reproduction,and life historytheory of trade-offs between reproduction and survival in animal with different body masses.