I did this way, may be even better
varlist=names(df)[i:j] #define what vars you want
blups.models <- lapply(varlist, function(x) {
lmer(substitute(i ~ (1|par1)+(1|par2)+(1|par3), list(i = as.name(x))), data = df, na.action=na.exclude)
})
here you have the list of models for all vars you want