THE ENERGETICS OF LACTATION IN THE NORTHERN ELEPHANT SEAL, MIROUNGA-ANGUSTIROSTRIS
THE ENERGETICS OF LACTATION IN THE NORTHERN ELEPHANT SEAL, MIROUNGA-ANGUSTIROSTRIS
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DOI：
10.1111/j.1469-7998.1986.tb03563.x
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发表时间：
1986-05-01
影响因子：
2
通讯作者：
ORTIZ, CL
中科院分区：
文献类型：
--
作者：
COSTA, DP;LEBOEUF, BJ;ORTIZ, CL
利用质量变化和水流入数据，测量了在26.5天的哺乳期，海象母亲向幼崽传递的能量和物质。在6只雌性象海豹和它们的幼崽身上监测了氚和氘标记水的稀释情况。在哺乳期间，幼崽的体重每天增加10.4%，而母崽的体重每天减少4.19%。在整个哺乳期间，女性体重下降了42.2。是他们最初体重的4.9%母犬向幼崽的质量转移是有效的；幼崽的体重增加了母亲体重损失的54.9%。女性的瘦体重只减少了14.9%，而脂肪却减少了57.9%。雌性的空腹代谢率为66.2 +-。7.5 mJ/天，是同等体型陆生哺乳动物预测标准代谢率（SMR）的2.41倍；总能量输出为163。11兆焦耳/天，是预测SMR的5.98倍。整个哺乳期的能量消耗为4330 .+-。460年乔丹。产奶占这一能量消耗的60%。这种高效的产奶量是通过哺乳和喂养的时间分离而实现的。从哺乳中分离觅食具有几个能量和生态上的优势：减少用于维持岸上新陈代谢的代谢负荷，减少满足哺乳需求所需的觅食努力，因为觅食可以分散在一个明显较长的间隔内，并且由于没有幼崽，在海上觅食时具有更大的灵活性。
The energy and material transferred from Northern elephant seal mothers to their pups during the 26.5-day lactation interval was measured using mass change and water influx data. The dilution of tritium- and deuterium-labelled water was monitored in six female elephant seals and their pups. During the nursing period, pup mass increased by 10.4% of the initial body mass per day while females lost 4.19% of their initial body mass per day. Over the entire nursing period, females lost 42.2 .+-. 4.9% of their initial body mass. Maternal mass transfer to the pup was efficient; pups gained 54.9% of the mass lost by their mothers. Females lost only 14.9% of their lean mass compared to 57.9% of their adipose mass. The fasting metabolic rate of females was 66.2 .+-. 7.5 mJ/day, 2.41 times the predicted standard metabolic rate (SMR) of a terrestrial mammal of equal size; the total energy output was 163 .+-. 11 MJ/day, 5.98 times the predicted SMR. Energy consumption for the entire lactation interval was 4330 .+-. 460 MJ. Milk production accounted for 60% of this energetic expenditure. This efficient milk production was made possible by temporal separation of lactation and feeding. Separation of feeding from lactation confers several energetic and ecological advantages: reduction in the metabolic overhead used for maintenance metabolism onshore, reduction of foraging effort required to meet the demands of lactation, since feeding can be spread out over a significantly longer interval, and a greater flexibility while foraging at sea due to the absence of the pup.