Burrin D G, Ferrell C L, Britton R A, Bauer M
Department of Animal Science, University of Nebraska, Lincoln 68583-0908.
Br J Nutr. 1990 Sep;64(2):439-48. doi: 10.1079/bjn19900044.
Thirty-two crossbred wether lambs (initial live-weight 31 kg) were fed on a diet (metabolizable energy (ME) 12.8 MJ/kg) ad lib. (ADLIB) or restricted to maintain body-weight (MAINT) for a 21 d period. On days 0, 7, 14 and 21, four lambs per treatment were slaughtered, visceral organs weighed and tissues sampled. During the 21 d period, ME intake in ADLIB lambs increased quadratically with an average rate of live-weight gain of 425 g/d. In MAINT lambs, live weight (30 kg) was maintained, and daily ME intake (kJ/kg empty body-weight (EBW)0.75) declined (P less than 0.01) quadratically with time. Weights of liver, stomach and small intestines as a percentage of EBW were increased in ADLIB lambs and decreased by 10-33% in MAINT lambs (treatment x day, P less than 0.01). In vitro liver oxygen consumption was not affected by level of feed intake. Estimates of whole-liver O2 consumption (mmol O2/d per kg EBW) increased in ADLIB lambs and were relatively constant in MAINT lambs. These findings suggest that level of feed intake changes the relative proportion of visceral organs to body mass. In addition, the effect of level of feed intake on changes in the relative contribution of visceral organs to whole-body metabolic rate appears to be primarily a result of differences in organ size rather than tissue-specific metabolic activity.
32只杂交去势公羔羊（初始活重31千克）被饲喂一种日粮（代谢能（ME）12.8兆焦/千克），自由采食（ADLIB）或限饲以维持体重（MAINT），为期21天。在第0、7、14和21天，每种处理宰杀4只羔羊，称量内脏器官重量并采集组织样本。在21天期间，ADLIB组羔羊的ME摄入量呈二次方增加，平均日增重率为425克/天。在MAINT组羔羊中，体重（30千克）保持不变，每日ME摄入量（千焦/千克空体重（EBW）0.75）随时间呈二次方下降（P<0.01）。ADLIB组羔羊肝脏、胃和小肠的重量占EBW的百分比增加，MAINT组羔羊则下降10%-33%（处理×天数，P<0.01）。体外肝脏耗氧量不受采食量水平的影响。ADLIB组羔羊全肝耗氧量估计值（每千克EBW每天的毫摩尔氧气量）增加，MAINT组羔羊相对恒定。这些发现表明，采食量水平改变了内脏器官与体重的相对比例。此外，采食量水平对内脏器官对全身代谢率相对贡献变化的影响似乎主要是器官大小差异的结果，而非组织特异性代谢活性的差异。
