nificance level of α = 0.05. The difference of the cholecalcif-erol concentrations in egg yolk of the 5 diets was examined
by GLM after the logarithm transformation. The relationship of cholecalciferol content in egg yolk and D3 enrichment level was fitted in a generalized linear model with gamma distribu- tion and identity link, and the likelihood-ratio test for lack of fit was conducted using R. The estimated deposition rate of cholecalciferol in yolk in response to dietary level (within the first 3 wk) was obtained by fitting the following linear model:
Yij k = (β0,i + β1,i X j ) • I X j ≤ 3 + εij k ,where Yij k denotes the