Briar Hens are a variant of the chicken in Slime Rancher 2 and are much less common – we have a location guide for you on where to find them in Ember Valley.
Slime Rancher 2 – Briar Hen Locations – Where to find
If you're looking for "Meat" in Slime Rancher 2, your only option to feed the Slimes is "Chickens". Even in the earlier parts of the game, you can find chickens roaming around the Rainbow Fields (East) and around The Conservatory.
Carnivorous Slimes include Pink Slimes, Ringtail Slimes, Tabby Slime and Angler Slime.
This does not include Gordo Slimes.