The objective was to develop statistical models to estimate variations in the population of Protozoa in the light of forage: concentrate ratio and the presence or absence of additives in the diet. Excel spreadsheets with data on diet composition, presence and absence of additives and the number of protozoa in the rumen of cattle for work done in Brazil were using. These variables were used and tested to obtain the equation for predicting the profile of the population of protozoa. The models obtained were checked by residual analysis and selection of variables was performed considering the significance level of 5%. It was found for the total count of protozoa and Entodinium that the increased proportion of large positive effect and additive ionophores had a negative effect. The use of statistical models can provide a better understanding of dietary factors on the microbiota of the rumen and on the animal.
rumen ciliates; rumen microbial; ruminants