。
There are lots of sheep on the farm.
Literal
Pasture [location-には] sheep [subject-が] lots exist-[animate-いる].
いる is the existence verb for animate beings, contrasted with ある for inanimate things. には marks the location with topic-emphasis: 'as for the pasture, (there are many).' たくさん ('lots') is the quantifier. A basic but natural existence sentence.