Effect of feeding a diet containing MiaTrace Zn or zinc oxide on productivity and health in weaned piglets
Published:August 9, 2019
Summary
Background and objectives The therapeutic use of zinc oxide in high doses (e.g. 2,500 ppm Zn) has yet demonstrated beneficial effects on growth performance in piglets as well as the prevention of post-weaning diarrhea. The precise mode of action is still not known, but recent results indicate that the zinc-ions affect the gastrointestinal milieu and thus prevent the adhesion of pathogens. The ...
I see problems here:
1. No actual BW or ADG values reported. Just p-values
2. Only a single FCR value reported, but P-values for all intermediate time points
Combined, points 1 and 2 suggest that the live animal performance was somehow unflattering. Either all performance was poor, or despite there being no statistically significant differences, the ZnO numerically out performed the MiaTrace product. With improved FCR being a result of reduced gain and feed intake, as opposed to increased gain and unchanged feed intake.
3. PTO is not a standard measurement.
4. PTO is significant on day 28 according to the p-value for the row, but not according to the multiple comparison test.
Disagreement between overall p-value (row)and the multiple comparison test p-value (superscript), or in fact the use of a multiple comparison test AT ALL suggests there is a 3rd (or possibly more) treatment(s) hidden from us.
Multiple comparison tests are not needed for a single pair-wise comparison (ZnO vs. MiaTrace), only when there are 2 or more comparisons, necessitating 3 or more treatments. (for example: ZnO vs MiaTrace, ZnO vs a negative control, MiaTrace vs. a negative control) If this is the case (or somethign like it) then the overall difference (P = 0.05 for the row) would be related to the control differing from the ZnO and MiaTrace, but no difference between each other.
Feels like someone is trying to put lipstick on a pig and hope we don't notice.