ENERGY EXPORT AND OFFSPRING GROWTH DURING LACTATION IN COTTON RATS (SIGMODON-HISPIDUS)
ENERGY EXPORT AND OFFSPRING GROWTH DURING LACTATION IN COTTON RATS (SIGMODON-HISPIDUS)
复制标题
DOI：
10.2307/2390558
复制
发表时间：
1995-04-01
影响因子：
5.2
通讯作者：
MCCLURE, PA
中科院分区：
文献类型：
--
作者：
ROGOWITZ, GL;MCCLURE, PA
1. 研究了哺乳期棉鼠（Sigmodon hispidus）的母体能量输出（乳汁）、食物摄入和质量损失与小窝（3只后代）和大窝（6只后代）哺乳后代生长的关系。 我们预测，能量输出将增加从早期到后期的哺乳期，为后代的生长提供能量，并与大尺寸的窝母亲可能会达到他们的能力，以滋养哺乳动物的限制。 哺乳小窝的母亲比那些大窝的母亲表现出更大的能力来应对不断增长的后代的能量需求。 从哺乳早期到后期，每只哺乳幼犬的化学能输出量增加。 相比之下，在整个哺乳期，大窝中个体幼崽的能量流仍然很低。 大窝仔个体能量流的低速率显著影响其出生后的生长。 大窝仔中的个体幼仔获得了能量含量为73.7%的牛奶，并且以小窝仔中幼仔的71.2%的速度生长。 大窝产奶动物所产的奶是稀的（有一小部分奶固体），每干质量的能量含量低于支持小窝产奶动物所产的奶。 支持大窝仔的母亲没有获得足够的能量从食物摄入或组织catenorization，以抵消低利率的能源出口到他们的后代。 食物摄入和组织分解的最大速率可能已经达到。 支持大窝（平均质量= 134克）的母亲的能量输出是一致的高。 能量流的峰值速率约为220千焦日-1.7。 这些结果表明，对大窝母亲的身体限制限制了产奶量，从而限制了后代的生长。
1. Maternal energy export (in milk), food intake and mass loss were examined in lactating Cotton Rats (Sigmodon hispidus) in relation to the growth of suckling offspring in small (three offspring) and large litters (six offspring). We predicted that energy export would increase from early to late lactation to provide energy for offspring growth, and that mothers with large-sized litters may reach a limit in their ability to nourish suckling young.2. Mothers nursing small litters showed a greater ability than those with large litters to respond to the energy demands of growing offspring. Their export of chemical energy per suckling pup increased from early to late lactation. In contrast, the energy flow to individual pups in large litters remained low throughout lactation.3. The low rate of energy flow to individual offspring in large litters significantly affected their postnatal growth. Individual pups in large litters obtained milk with 73.7% the energy content and grew at 71.2% the rate of pups in small litters.4. The milk produced by lactating animals with large litters was dilute (had a small fraction of milk solids) and had a lower energy content per dry mass than did the milk produced by animals supporting small litters.5. Mothers supporting large litters did not acquire sufficient energy from food intake or tissue catabolism to offset the low rate of energy export to their offspring. Maximal rates of food intake and tissue catabolism may have been attained.6. The energy export by mothers supporting large litters (mean mass = 134 g) was uniformly high. The peak rate of energy flow was approximately 220 kJ day-1.7. These results indicate that physical constraints on mothers with large litters limit milk production and, consequently, offspring growth.