Statistical approaches for treatments over time (repeated observations)‎ in Nile tilapia

الملخص EN

This study aims to model and analyze repeated observations in some biological sciences and veterinary practices (Nile tilapia fish).

Repeated measure ANOVA is used to assess the effect of some treatments over a specific time.

Data obtained from an experimental study examining the effect of some immunostimulants (Spirulina platensis (SP) and Salvia officinalis (SO)) on lysozymes activity in Nile tilapia fish which measured repeatedly at two times.

The analysis is applied by using the software SPSS version 20 on the data collected at two time points 14th day and 28th day so the correct test was two way repeated measure design.

The assumptions of the test were achieved where Huynh-Feldt and Greenhouse-Geisser measures were not significant (P-value > 0.05).

The P value for time, treatments and the interaction of them was 0.000, so they have a highly significant effect on the (outcome variable) lysozymes activity of Nile tilapia.

Bonferroni correction is used as a post hoc test and its result showed a difference between the groups for each parameter.

These results of univariate analysis agreed with the multivariate analysis results.