Hoofed mammal in Kansas occasionally (3)
I believe the answer is:
ass
'hoofed mammal' is the definition.
(ass is a kind of hoofed mammal)
'kansas occasionally' is the wordplay.
'occasionally' means one should take alternating letters.
The alternate letters of 'kansas' are 'ASS'.
'in' is the link.
(Other definitions for ass that I've seen before include "Turkey" , "Dipstick" , "Silly fellow in passionate state" , "Nincompoop" , "An American backside" .)