Statistical Analysis
Observations were marked as outliers and excluded
from the data set before statistical analyses if an observation
exceeding the parameter mean by more than
2.5 times the SD. The experimental data were analyzed
by ANOVA (GLM procedure) using GenStat statistical
software (14th edition, VSN International Ltd., Hemel
Hempstead, UK). Data were analyzed according to the
following model:
Yij = μ + Blocki + Treatmentj + eij,
where Y is the response parameter, μ is the overall
mean, Block is the effect of replicated block (i = 1
to 5 or 6), Treatment is the effect of zinc source and
dose level (j = 1 to 9), and e is the random error term.
Treatment means were compared by least significant
differences. A P-value < 0.05 was considered to be statistically
significant, whereas 0.05 ≤ P < 0.10 was considered
to be a near-significant trend.
The dose-response relationship between zinc level
on tibia zinc content was tested for linearity per zinc
source. Subsequently, the slope ratios of both zinc
sources were calculated. The slope ratio of zinc sulfate
was used as a reference to estimate the relative bioavailability
of the organic zinc source.