Miski A M, Quazi S
Poult Sci. 1981 Apr;60(4):781-5. doi: 10.3382/ps.0600781.
Two experiments were conducted to study the influence of age, sex, body weight, and strain of the bioassay bird on its 24-hr combined endogenous urinary and metabolic fecal energy (Yec) losses, expressed as kJ/100 g body weight per 24 hr. In the first experiment, one-day-old broiler chicks of mixed sexes were used and their Yec losses determined at 18, 32, 47, 62, 77, 92, and 107 days of age. In the second experiment, the Yec losses of four White Leghorn roosters were determined at 122 days of age only. Birds were fed a commercial broiler-starter diet through-out the experimental period. It was concluded that the sex of the broiler chick between 18- and 107-days of age does not affect the Yec losses, i.e., the energy the unfed bird loses daily per unit body weight in its voided excreta. However, the average Yec losses expressed (either per unit body weight or per unit body size, Wkg.75 were influenced by age. The Yec losses showed a progressive fall as broiler chicks progressed in age between 18 and 77 days of age and later were stabilized at a minimum between 77 and 107 days of age. As the observed decrease in the Yec losses with increases in age followed a similar trend to that reported in the literature for the basal metabolic rate (BMR) energy needs of the chick, it was tentatively concluded that the Yec losses of broiler chicks vary with age according to the BMR energy needs per unit body weight of the animal. The average Yec losses of White Leghorn roosters at 122 days of age was significantly higher than that of 107-day-old broiler pullets even though the average weight of the rooster was only 53% that of the pullets. It was tentatively concluded that variations existing in the Yec losses of adult birds of same or different strains and sex are mainly attributed to differences in their body composition and BMR energy needs. However, further research is needed in order to verify this conclusion.
进行了两项实验，以研究生物测定鸡的年龄、性别、体重和品系对其24小时内源性尿液和代谢粪便能量（Yec）损失的影响，以每24小时千焦/100克体重表示。在第一个实验中，使用了混合性别的一日龄肉鸡雏鸡，并在18、32、47、62、77、92和107日龄时测定它们的Yec损失。在第二个实验中，仅在122日龄时测定了四只白来航公鸡的Yec损失。在整个实验期间，给鸡喂食商业肉鸡育雏日粮。得出的结论是，18至107日龄的肉鸡雏鸡的性别不影响Yec损失，即未进食的鸡每天在其排出的粪便中每单位体重损失的能量。然而，所表达的平均Yec损失（无论是每单位体重还是每单位体表面积，Wkg.75）受年龄影响。随着肉鸡雏鸡年龄从18天增长到77天，Yec损失呈逐渐下降趋势，随后在77至107天之间稳定在最低水平。由于观察到的Yec损失随年龄增加而减少的趋势与文献中报道的雏鸡基础代谢率（BMR）能量需求的趋势相似，初步得出结论，肉鸡雏鸡的Yec损失根据动物每单位体重的BMR能量需求随年龄而变化。122日龄白来航公鸡的平均Yec损失显著高于107日龄的肉鸡小母鸡，尽管公鸡的平均体重仅为小母鸡的53%。初步得出结论，相同或不同品系和性别的成年鸡Yec损失存在的差异主要归因于它们身体组成和BMR能量需求的差异。然而，需要进一步研究以验证这一结论。
