Yes, and quite big ones at that.>Lactating females can carry 3–4 kg (6.6–8.8 lb) of milk in their udders.>Spotted hyena milk has the highest protein and fat content of any terrestrial carnivore.
That's over one gallon of the highest quality milk you can get.
To put that into perspective, Holstein cows typically hold around 14kg of milk in their udders. While that is, in absolute terms, much higher than hyenas, things are a bit different when looking at proportional milk production. In a Holstein cow, their milk makes up approximately two percent of their weight. In hyenas, however, their milk makes up approximately five percent of their weight. A Holstein cow produces ten tons of milk per year. A spotted hyena of the same size would produce nearly twenty-six tons of milk in the same timeframe.
Tl;dr hyenas continue to mog everything else.