NITROGEN-METABOLISM IN GENETICALLY FAT AND LEAN CHICKENS
NITROGEN-METABOLISM IN GENETICALLY FAT AND LEAN CHICKENS
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DOI：
10.3382/ps.0691911
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发表时间：
1990-11-01
期刊：
影响因子：
4.4
通讯作者：
LECLERCQ, B
中科院分区：
文献类型：
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作者：
GERAERT, PA;MACLEOD, MG;LECLERCQ, B
本试验旨在研究饲粮蛋白质含量（试验1为170 ~ 230 g/g，试验2为137 ~ 251 g/kg）和初始生长率（以4周龄活重计算）对遗传肥（FL）和瘦（LL）种鸡4 ~ 7周龄生长速率、氮沉积、能量代谢和氨基酸分解代谢的影响。在能量利用方面，无论是代谢率还是消耗（基础代谢率、维持或饮食诱导的产热），品系之间都没有差异。细胞系之间唯一的差异是在脂质和蛋白质沉积之间相似的保留能量的分配上。在两个试验中，LL鸡的蛋白质保留效率均高于FL鸡；此外，LL系对饲粮低蛋白质含量的敏感性并不高于FL系。根据生长率或4周龄活重进行选择，可选择不同的育肥率。事实上，生长缓慢的FL和LL鸡在氮代谢方面的差异小于生长迅速的鸟类，后者也更胖。FL鸡较低的蛋白质保留效率与饲粮中氨基酸降解的增加有关，这与饲粮中尿酸排泄率的增加有关。
Two experiments were conducted to investigate the effect of dietary protein content (170 to 230 g/g in Experiment 1 and 137 to 251 g/kg in Experiment 2) and initial growth rate, estimated from live body weight at 4 wk of age, on growth rate from 4 to 7 wk of age, nitrogen retention, energy metabolism, and amino acid catabolism in genetically fat (FL) and lean (LL) lines of chickens. There was no difference between lines in energy utilization either in metabolizability or in expenditure (basal metabolic rate, maintenance, or diet-induced thermogenesis). The only divergence between lines was in the partition of a similar amount of retained energy between lipid and protein deposition. In both experiments, LL chickens showed greater protein retention efficiency than FL birds; moreover, the LL line did not appear more sensitive to low dietary protein contents than the FL line. Selecting birds on their growth rate or live body weight at 4 wk of age resulted in the selection of different rates of fattening. Indeed, the slow-growing FL and LL chickens differed less in their nitrogen metabolism than did fast-growing birds, which were also fatter. The lower protein retention efficiency observed in FL chickens was related to an increase of dietary amino acid degradation as revealed by a greater rate of uric acid excretion in the fed state.