The relation between the size of southern elephant seal mothers, the growth of their pups, and the use of maternal energy, fat and protein during lactation
The relation between the size of southern elephant seal mothers, the growth of their pups, and the use of maternal energy, fat and protein during lactation
复制标题
DOI：
10.1086/physzool.69.4.30164234
复制
发表时间：
1996-07-01
期刊：
影响因子：
--
通讯作者：
Boyd, IL
中科院分区：
文献类型：
--
作者：
Fedak, MA;Arnbom, T;Boyd, IL
怀孕的雌性南象海豹在上岸分娩和护理幼崽时，体型的变化超过三倍。幼崽完全由母亲的身体储备喂养，这与她分娩时的体重成比例。我们测量了使用的身体材料和能量在哺乳过程中使用的同位素稀释和质量变化相结合，在四个繁殖季节南格鲁吉亚。平均而言，母亲在哺乳期分娩时失去了35%的质量。这包括母亲体内大约52%的能量，61%的脂肪和24%的蛋白质。母亲在幼崽身上花费的相对数量变化很大，与母亲的体重几乎没有一致的趋势。一些大的母亲使用大约30%的储存能量（包括大约40%的储存脂肪和20%的身体蛋白质）来生产中型或大型的幼崽。虽然一些较小的母亲只生产小的幼崽，但其他人使用了所有或更多的储备，估计不会产生有害影响（68%的能量，80%的脂肪和27%的蛋白质）。这些小动物可能会危及它们未来的繁殖。由这些较小的雌性产生较小的幼崽可能反映了幼崽的生存和母亲未来成功之间的妥协。虽然我们预计，最大的女性可能会表现出降低效率，在哺乳期间的质量转移（因为高代谢费用），他们的能力，以减少哺乳期的持续时间似乎弥补了这一点，并没有这样的减少可以显示。
Pregnant female southern elephant seals vary in size by more than a factor of three when they come ashore to give birth and nurse their pups. Pups are fed exclusively from the mother's body reserves, which vary in proportion to her mass at parturition. We measured the use of body materials and energy over the course of lactation using a combination of isotope dilution and mass change during four breeding seasons on South Georgia. On average, mothers lost 35% of their mass at parturition during lactation. This included approximately 52% of the energy, 61% of the fat, and 24% of the protein in the mother's body. The relative amount that mothers expend on their pups is highly variable and shows little consistent trend with the mother's mass. Some large mothers used approximately 30% of their stored energy (comprising around 40% of stored fat and 20% of body protein) to produce medium- or large-sized pups. Whereas some smaller mothers produced only small pups, others used all of or more than the reserves estimated to be available without incurring deleterious effects (68% of energy, 80% of fat, and 27% of protein). These small animals may be at risk of compromising their future reproduction. The production of small pups by these smaller females ma3' reflect a compromise between the survival of the pup and the future success of the mother. While we expected that the largest females might show a reduced efficiency, of mass transfer during lactation (because of high metabolic overheads), their ability, to reduce the duration of lactation seems to compensate for this, and no such reduction could be shown.