Akpe M P, Waibel P E, Larntz K, Metz A L, Noll S L, Walser M M
Poult Sci. 1987 Apr;66(4):713-20. doi: 10.3382/ps.0660713.
Two experiments were conducted to examine the relative precision of bone densitometry and bone ash methodologies as response criteria in measurement of bioavailability of phosphorus from various supplements for turkeys. Multivariate analyses of variance were used to analyze data collected. Coefficients of correlation and variation and F ratios were used for evaluation. Bone densitometry with one scan at each of 3 points on the bone was faster than bone ash and as precise as bone ash analysis in measuring phosphorus availability in turkeys. The coefficient of correlation between percentage ash (of dry bone) and scan density (milligrams per centimeter length of bone) measurements for treatment effects was .986. The coefficient of variation was about the same for the bone ash (5.8) and the three-point bone scan (6.9) methods. As indicated by the F ratio for testing treatment effects, bone densitometry was better able to detect differences among phosphorus sources. A technician may scan 50 cleaned bones in 3 hr, but with the bone ash method, drying, ashing, and weighing may require 3 working days. Bone sampling technique, multiple operators, different bone sizes, and decay of iodine source were the major factors affecting precision of the bone densitometry technique. Relative biological availabilities of phosphorus from various supplements were about the same by the two methods.
进行了两项试验，以检验骨密度测定法和骨灰测定法作为衡量火鸡各种磷源生物利用率响应标准的相对精度。采用多变量方差分析来分析收集到的数据。使用相关系数、变异系数和F比率进行评估。在火鸡磷利用率的测定中，对骨骼上3个点各进行一次扫描的骨密度测定法比骨灰测定法更快，且与骨灰分析的精度相同。处理效应下，（干骨）骨灰百分比与扫描密度（每厘米骨骼长度毫克数）测量值之间的相关系数为0.986。骨灰法（5.8）和三点骨扫描法（6.9）的变异系数大致相同。从检验处理效应的F比率来看，骨密度测定法更能检测出磷源之间的差异。一名技术人员在3小时内可扫描50块清洁骨骼，但采用骨灰法时，干燥、灰化和称重可能需要3个工作日。骨采样技术、多名操作人员、不同骨骼大小以及碘源衰减是影响骨密度测定技术精度的主要因素。两种方法测得的各种磷源的相对生物学利用率大致相同。
