Sibbald I R, Morse P M
Poult Sci. 1984 May;63(5):954-71. doi: 10.3382/ps.0630954.
The change in carcass composition associated with intake of true metabolizable energy (TME) by young broiler chicks was investigated. The experiment comprised 17 treatments, 16 of which formed a 2 X 4 X 2 factorial design with six replications; the experimental unit was a pen of four male chicks. The factorial treatments consisted of two basal diets (lipogenic and proteogenic ), four levels of cellulose dilution (to cause a range of basal diet intakes), and two feeding periods (10 to 17 and 10 to 24 days of age). The birds were fed ad libitum, feed intake was recorded, and final carcass composition was measured. The 17th treatment comprised 24 pens of chicks killed at the start of the experiment to estimate initial carcass composition. The gross energy of carcass fat and protein was estimated by chemical and physical analysis and by regression analysis, the latter yielded estimates of 24.5 and 39.5 MJ/kg for protein and fat, respectively. Basal diet intake was reduced by more than 50% at the highest level of cellulose dilution and increased by about 60% when the feeding period was extended from 17 to 24 days. Pen weight gain and carcass composition were affected by basal diet intake. The energy retained in the carcass (MJ/W X 75 kg/day) (RE') increased in a linear manner with the intake of TME (MJ/W X 75 kg/day) ( ITME ), the slope of the line being greater for the lipogenic than for the proteogenic diet. Projected back to zero ITME ', the regression lines for pens in positive energy balance gave an estimate of .420 MJ loss, After 7 days on experiment, the energy retained as fat (RE'f) and as protein (RE'p) increased approximately linearly with ITME ', but after 14 days some curvature was apparent, the deposition of protein increasing more rapidly at the lower levels of energy input, and the deposition of fat increasing more rapidly at the higher levels of energy input. The RE'p was only slightly higher on the proteogenic diet than on the lipogenic diet, at the same level of ITME ', but the effect of basal diet on RE'f was considerable. For both diets at RE' = 0 there was gain in body protein accompanied by loss of body fat.
研究了肉仔鸡摄入真代谢能（TME）后胴体组成的变化。试验包括17个处理，其中16个处理采用2×4×2析因设计，重复6次；试验单元为每栏4只雄性雏鸡。析因处理包括两种基础日粮（生脂日粮和生蛋白日粮）、四个纤维素稀释水平（以形成一系列基础日粮摄入量）和两个饲喂期（10至17日龄和10至24日龄）。雏鸡自由采食，记录采食量，并测定最终胴体组成。第17个处理包括24栏雏鸡，在试验开始时宰杀，以估计初始胴体组成。通过化学和物理分析以及回归分析估计胴体脂肪和蛋白质的总能，回归分析得出蛋白质和脂肪的估计值分别为24.5和39.5 MJ/kg。在纤维素稀释水平最高时，基础日粮摄入量减少超过50%，当饲喂期从17天延长到24天时，基础日粮摄入量增加约60%。栏增重和胴体组成受基础日粮摄入量的影响。胴体中保留的能量（MJ/W×75 kg/天）（RE'）随TME摄入量（MJ/W×75 kg/天）（ITME）呈线性增加，生脂日粮的直线斜率大于生蛋白日粮。将回归线外推至零ITME'，处于正能量平衡栏的回归线给出了0.420 MJ损失的估计值。试验7天后，作为脂肪（RE'f）和蛋白质（RE'p）保留的能量随ITME'大致呈线性增加，但14天后出现了一些曲线，在较低能量输入水平下蛋白质沉积增加更快，在较高能量输入水平下脂肪沉积增加更快。在相同ITME'水平下，生蛋白日粮的RE'p仅略高于生脂日粮，但基础日粮对RE'f的影响相当大。对于两种日粮，当RE' = 0时，体蛋白增加而体脂肪减少。
