Categorical covariates

[AlexandreHUBERT17]

Hi,

I try to include a qualitative covariate: the cage ID.
GEMMA seems to take into account the numerical variables.
If I transform the cages into numbers, will GEMMA perform a regression? This would be wrong because it requires an effect calculation for each cage.

Can you explain how GEMMA corrects the model for a qualitative effect?

Thanks in advance