Aardsma M P, Parsons C M
Department of Animal Sciences, University of Illinois at Urbana-Champaign, IL.
Department of Animal Sciences, University of Illinois at Urbana-Champaign, IL
Poult Sci. 2017 Jan 1;96(1):108-117. doi: 10.3382/ps/pew184. Epub 2016 Jun 22.
The precision-fed rooster assay (PFRA) frequently yields TME values for fats and oils in excess of their gross energies. Six experiments were conducted to determine if the PFRA could be combined with a slope-ratio type assay to yield more useful lipid TME values. In experiment (EXP) 1, refined corn oil (RCO) was fed to conventional and cecectomized roosters at zero, 5, 10, 15, and 20% of a ground corn diet. In EXP 2 through 6, lipids were fed to conventional roosters at zero, 5, and 10% in a ground corn diet. Palomys (a novel lipid), high stearidonic acid soybean oil (SDASO), 2 animal-vegetable blends (AV1, AV2), a vegetable-based oil blend (VB), and corn oil from an ethanol plant (DDGSCO) were evaluated and compared to refined soybean oil (RSO) or RCO as the reference lipid. Multiple linear regression of diet TME on supplemental lipid level generated regression coefficients that were used to calculate relative bioavailability values (RBV). In EXP 1, RCO was a suitable reference material as TME linearly increased up to 20% RCO inclusion. There were some minor differences in TME of RCO between conventional and cecetomized bird types. In EXP 2, Palomys was found to have a lower (P < 0.05) RBV (87%) than RCO. In EXP 3, there were no significant differences between SDASO and RSO. In EXP 4, the RBV of AV2 (79%) was lower (P < 0.05) than RCO, while the RBV of AV1 was not different from RCO. The RBV of DDGSCO (116%) was higher (P < 0.05) than RCO in EXP 5. The RBV of VB (84%) was lower (P < 0.001) than RCO in EXP 6; however, this may be an underestimation for low levels of VB, as there was an interaction (P < 0.01) between lipid type and lipid supplementation level. These results indicate that the precision-fed slope-ratio rooster assay can detect differences among lipids and yields practically useful lipid TME values.
精确饲喂公鸡试验（PFRA）测定的脂肪和油类的真代谢能（TME）值常常超过其总能。开展了六项试验，以确定PFRA是否可与斜率比型试验相结合，从而得出更有用的脂质TME值。在试验（EXP）1中，将精炼玉米油（RCO）以占玉米基础日粮0%、5%、10%、15%和20%的比例饲喂给常规公鸡和切除盲肠的公鸡。在试验2至6中，将脂质以占玉米基础日粮0%、5%和10%的比例饲喂给常规公鸡。对Palomys（一种新型脂质）、高十八碳四烯酸大豆油（SDASO）、两种动植物混合油（AV1、AV2）、一种植物基混合油（VB）以及来自乙醇工厂的玉米油（DDGSCO）进行了评估，并与精炼大豆油（RSO）或RCO作为参考脂质进行比较。日粮TME对补充脂质水平的多元线性回归产生了回归系数，用于计算相对生物利用率值（RBV）。在试验1中，RCO是一种合适的参考物质，因为当RCO添加量高达20%时，TME呈线性增加。常规公鸡和切除盲肠的公鸡类型之间，RCO的TME存在一些细微差异。在试验2中，发现Palomys的RBV（87%）低于RCO（P < 0.05）。在试验3中，SDASO和RSO之间没有显著差异。在试验4中，AV2的RBV（79%）低于RCO（P < 0.05），而AV1的RBV与RCO没有差异。在试验5中，DDGSCO的RBV（116%）高于RCO（P < 0.05）。在试验6中，VB的RBV（84%）低于RCO（P < 0.001）；然而，这可能低估了低水平的VB，因为脂质类型和脂质添加水平之间存在交互作用（P < 0.01）。这些结果表明，精确饲喂斜率比公鸡试验能够检测脂质之间的差异，并得出实际有用的脂质TME值。
