Pellets livestock ultimately pick at? Not the first (6)
I believe the answer is:
kibble
'pellets livestock ultimately pick at? not the first' is the definition.
I can't tell whether this definition defines the answer.
'livestock ultimately pick at? not the first' is the wordplay.
'ultimately' suggests the final letters.
'pick at?' becomes 'nibble' ('nibble' can be a synonym of 'pick at').
'not the first' means to remove the first letter.
The last letter of 'livestock' is 'k'.
'nibble' with its initial letter taken off is 'ibble'.
'k'+'ibble'='KIBBLE'
Can you help me to learn more?
(Another definition for kibble that I've seen is " Crush or grind grain coarsely".)