*2.7. Statistical Analysis*

Statistical analyses were performed using IBM SPSS Statistics 25. Means and standard errors of the means were computed for all parameters separately for each treatment. To determine the differences in growth performance, carcass, and meat quality parameters for all treatments, we applied one-way analysis of variance (ANOVA). The statistical model used was as follows:

$$\chi\_{i\bar{\eta}k} = \mu + T\_{\bar{\imath}j} + e\_{i\bar{\jmath}k}$$

where *Yijk* is *k*- investigated the characteristics of *j*- bull within *i*-treatment, *μ* is total mean, *Tij* is the *j*-bull of *i*-treatment (CON, TAN 1, TAN 2, TAN 3), and *eijk* is error component.

The assumptions of normality and homoscedasticity were verified using Shapiro– Wilk's and Levene's tests. In case of finding significant results in an ANOVA, post hoc analysis using the Duncan method was performed.

One-way ANOVA was applied to examine the differences in the total number of *Clostridia* (MPN) at the beginning and the end of the feeding trial. In the case of selected *Clostridium,* the non-parametric Kruskal–Wallis test was used and pairwise comparisons were performed using the Dunn–Bonferroni post hoc test. If the *p*-value was lower than 0.05, the results were considered significant.
