Effects of birth weight and postnatal nutrition on neonatal sheep: I. Body growth and composition, and some aspects of energetic efficiency.
Effects of birth weight and postnatal nutrition on neonatal sheep: I. Body growth and composition, and some aspects of energetic efficiency.
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出生体重和产后营养对新生羊的影响：I.身体生长和组成，以及能量效率的某些方面。
DOI：
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发表时间：
1998
影响因子：
3.3
通讯作者：
Alan W. Bell
中科院分区：
文献类型：
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作者：
Paul L. Greenwood;A. S. Hunt;John W. Hermanson;Alan W. Bell
研究了初生重和产后营养对羔羊生长发育的影响。低出生体重和高出生体重的雄性羔羊单独饲养在高质量的流质饲料中，以快速（随意获取饲料）或缓慢（ADG 150 g）生长至各种体重，最高可达20 kg活重（LW）。高出生体重羔羊（平均值+/-SE 345+/-14 g）的平均日增重往往高于自由采食的低出生体重羔羊（329+/-15 g），这是由于产后期间新生羔羊较小，生长较慢。在出生时，在特定体重的基础上，小新生儿比高出生体重的新生儿含有少6.4%的氮，并且往往含有更多的灰分（8.9%）。每日的脂肪，灰分，和GE增长率更大，氮的增长往往是更大的快速增长的大型新生儿比他们的小同行。在任何给定的空体重（EBW）在饲养过程中，低出生体重羔羊含有更多的脂肪和更少的灰分，导致缓慢和快速增长的小新生儿分别含有39.3和42.7 Mcal GE，在研究完成时（17.5 kg EBW），而在他们的大同行34.8和40.5 Mcal。出生体重类别之间的脂肪和能量含量的差异归因于维持的能量需求约低30%，再加上出生后早期低出生体重羔羊的相对摄入量较高。此时，消耗超过瘦组织生长需求的营养物的能力在小的新生儿中比在大的新生儿中明显更明显，这导致用于组织沉积的能量利用效率较低。此外，身体组成之间的差异缓慢和快速饲养羔羊支持的概念，优先瘦肉组织脂肪时，营养供应有限。
We investigated the effects of birth weight and postnatal nutrition on growth characteristics of neonatal lambs. Low- and high-birth-weight male lambs were individually reared on a high-quality liquid diet to grow rapidly (ad libitum access to feed) or slowly (ADG 150 g) to various weights up to 20 kg live weight (LW). Average daily gain tended to be greater in the high- (mean+/-SE 345+/-14 g) than in the low- (329+/-15 g) birth-weight lambs given ad libitum access to feed owing to slower growth by the small newborns during the immediate postpartum period. At birth, on a weight-specific basis, small newborns contained 6.4% less nitrogen and tended to have more ash (8.9%) than the high-birth-weight newborns. Daily rates of fat, ash, and GE accretion were greater, and nitrogen accretion tended to be greater in the rapidly grown large newborns than in their small counterparts. At any given empty body weight (EBW) during rearing, low-birth-weight lambs contained more fat and less ash, resulting in slowly and rapidly grown small newborns containing 39.3 and 42.7 Mcal GE, respectively, at completion of the study (17.5 kg EBW), compared with 34.8 and 40.5 Mcal in their large counterparts. The differences in fatness and energy content between the birth weight categories are attributed to energy requirements for maintenance that were approximately 30% lower, coupled with higher relative intakes in the low-birthweight lambs, during the early postnatal period. At this time, the ability to consume nutrients in excess of lean tissue growth requirements was apparently more pronounced in small than in large newborns, which resulted in lower efficiency of energy utilization for tissue deposition. Furthermore, body composition differences between the slowly and rapidly reared lambs support the notion of a priority of lean tissue over fat when nutrient supply is limited.