INTAKE AND USE OF MILK NUTRIENTS BY RAT PUPS SUCKLED IN SMALL, MEDIUM, OR LARGE LITTERS
INTAKE AND USE OF MILK NUTRIENTS BY RAT PUPS SUCKLED IN SMALL, MEDIUM, OR LARGE LITTERS
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DOI：
10.1152/ajpregu.1991.260.6.r1104
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发表时间：
1991-06-01
影响因子：
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通讯作者：
REEDS, PJ
中科院分区：
文献类型：
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作者：
FIOROTTO, ML;BURRIN, DG;REEDS, PJ
我们调查了不同大小的窝（每窝 4、10 和 16 只幼仔）中哺乳的大鼠幼仔的体重增加变化在多大程度上归因于乳汁营养摄入的差异。在对测量期间沉积在身体组织中的水和乳碳进行校正后，根据在 4、8 和 14 日龄施用的 (H2O)-H-3 剂量在 2 天内的稀释率来估计牛奶摄入量。蛋白质和能量的摄入量是根据每只幼崽消耗的牛奶量和每只母犬的牛奶成分来估算的。观察到产仔数对乳脂和蛋白质浓度的显着影响。在 4 和 10 窝中哺乳的幼崽中，体重增加与能量摄入高度相关，但在 16 窝中则不然。这些发现归因于 10 日龄以下、在 16 窝中哺乳的幼崽能量消耗较高；具体来说，这些幼崽比 4 和 10 窝中的幼崽具有更高的维持能量需求，并且组织合成的能量成本更高。后者归因于未成熟幼崽能够最大限度地提高蛋白质利用效率，从而减弱营养摄入减少对蛋白质沉积的有害影响。
We investigated the extent to which the altered weight gain of rat pups suckled in litters of varying sizes (4, 10, and 16 pups/litter) is attributable to differences in milk nutrient intake. Milk intake was estimated from the rate of dilution over 2 days of a dose of (H2O)-H-3 administered at 4, 8, and 14 days of age after correction for the water and milk carbon deposited in body tissues over the measurement period. Protein and energy intakes were estimated from the volume of milk consumed by individual pups and the composition of milk from each dam. Significant effects of litter size on milk fat and protein concentration were observed. Weight gain was highly correlated with energy intake in pups suckled in litters of 4 and 10 but not 16. These findings were attributed to a higher energy expenditure of pups < 10 days old suckled in litters of 16; specifically these pups had higher maintenance energy needs than pups suckled in litters of 4 and 10 and a higher energy cost of tissue synthesis. The latter was ascribed to an ability of immature pups to maximize the efficiency of protein utilization, thereby blunting the deleterious effects of a reduced nutrient intake on protein deposition.