Ex-vivo growth rates of selected bacterial groups in stomach and jejunum samples of piglets fed diets containing 57 ppm (low Zn) or 2425 ppm (high Zn) dietary zinc oxide (n  = 4); significant differences between treatment groups highlighted in bold).

a, b<p>Means within rows for each zinc concentration and intestinal segment with different superscripts differ (<i>P</i><0.05; Mann-Whitney U test).