WY-test statistics.

<p>Test statistics from WY-tests with 15% trimming for the silica concentration, microwear (primary surface only) and texture analyses of the primary surface (A), S-F surface (B), and S-L surface (C).</p><p>Values in bold indicate a significant difference (<i>p</i>≤0.05). <i>Ft</i> = test statistics, nu1 and nu2 = 1^st and 2^nd degree of freedom, <i>p</i> = significance level, <i>SC</i> = silica concentration [%] in animal feeds, <i>Np</i> = number of pits, <i>Ls</i> = length of scratches (µm), <i>Sda</i> = closed dale area [µm²], <i>Sdv</i> = closed dale volume [µm³], <i>S5v</i> = five point pit height [µm], <i>Sal</i> = auto correlation length [µm], <i>Sp</i> = maximum peak height [µm], <i>Ssk</i> = skewness, <i>Sv</i> = maximum pit height [µm], <i>Sz</i> = maximum height [µm].</p

Description of the ISO/FDIS 25178 parameters.

<p>Description and units of the applied parameters are indicated according to ISO/FDIS 25178 analysis. The most effective parameters that are found to discriminate rabbit diets are set in bold.</p

Schematic models.

<p>Schematic models of hypothetical surface textures indicating the parameter value of the ISO/FDIS 25178 parameter closed dale area (<i>Sda</i>) or maximum peak height (<i>Sp</i>) having high (left) or low values (right).</p

Box plots and discriminant analysis plot.

<p>Box plots indicating (a) the silica concentration (SC, %) in animal feeds, the microwear parameters (b) number of pits (<i>Np</i>), (c) length of scratches (<i>Ls</i>), the ISO/FDIS 25178-2 parameters: (d) closed dale area (<i>Sda</i> on primary surface, µm²), (e) maximum peak height (<i>Sp</i> on S-L surface, µm) within the feeding groups (G = grass meal, GO = grass meal with crushed oats, LO = lucerne with crushed oats, and L = lucerne), * = <i>p</i>≤0.05. Box plots showing the median (middle line), the interquartile range (IQR, box) and the minimum/maximum values 1.5×IQR (whiskers), extreme values are excluded. Discriminant analysis (f) using microwear (<i>Np</i>, <i>Ls</i>) and texture parameters (<i>Sda</i> on primary surface, <i>Sp</i> on S-L surface) indicating significant group differences (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056167#pone-0056167-t002" target="_blank">Table 2</a>). The canonical discriminant function coefficients are <i>Np</i>_score1/2 = 0.038/0.015, <i>Ls</i>_{score 1/2} = −0.128/−0.014, <i>Sda</i>_score1/2 = −0.532/0.015, <i>Sp</i>_{score 1/2} = −0.076/−0.226.</p