great, huge, large, vast
small
entire, whole
national (= all the animals of a particular type in a country)
Bad weather has decimated the national herd.

beef, breeding, dairy
The farm has only a small dairy herd.

pedigree (BrE)
wild
cattle, cow, elephant, etc.

instinct

in a/the herd
The animals tend to graze in a herd.

herd of
a large herd of cows

a member of a herd

common
thundering (esp. AmE)
They hired a thundering herd of corporate executives.

follow
If you feel so strongly, why follow the herd (= do the same as everybody else)?

stand apart from (AmE), stand out from
She prided herself on standing out from the common herd.

instinct, mentality