The poem
The widest prairies have electric fences, For though old cattle know they must not stray Young steers are always scenting purer water Not here but anywhere. Beyond the wires
Leads them to blunder up against the wires Whose muscle-shredding violence gives no quarter. Young steers become old cattle from that day, Electric limits to their widest senses.

Wires is a lovely poem.Taken literally it is simply a poem about a bunch of cows but on a symbolic level it is about the rebelliousness of youth and the problems they have with authority.They are the 'young steers' who are scenting new waters -they are always finding something new and interesting to do. The elctric fence is the law or authority who dispense justice on these cattle. When the youth have been dealt…
Read the whole commentWires is a lovely poem.Taken literally it is simply a poem about a bunch of cows but on a symbolic level it is about the rebelliousness of youth and the problems they have with authority.They are the 'young steers' who are scenting new waters -they are always finding something new and interesting to do. The elctric fence is the law or authority who dispense justice on these cattle. When the youth have been dealt with by '...muscle shredding violence...' they become 'old steers', with the law a firm guiding system in their life.They will no longer search out new water because they do not want to 'blunder up against wires...'.
It's quite sympatheic in tone and I think Larkin feels quite sad that their freedom and innocence has been lost once they go against that electric fence, which will be ever present in their minds.
Another interesting thing to note about this poem is the rhyme scheme.The first and last lines of the poem rhmes and the second line and second to last line rhyme and so on.Sadly I can't remember the correct term for this sort of rhmye.
This particular rhyme scheme is called arch-rhyme.
Rachel's analysis is perfect, but i'd like to add a final consideration. Larkin conveys the "wisdom" of conformity and implictly critizices society's limitations imposed to its whole population.
'always finding something new and interesting to do'. I'm not sure they ever do get beyond the wires. They may want to but they can't escape. The wires aren't any literal authority but life, society, the tangible. Our youthful hopes are crushed violently by the realisation that we are fenced in and once we realise, once we give up on finding an exit from this mediocre world, we become old cattle.
Wires
Wires is another of Larkin's poetry that seems to convey both a sense of hopelessness but also an epiphany of sorts - that last line, as he guides us to a greater understanding of humanity. There is added resonance in that last line - the "electric limits" - in today's digital age. The structure of the poem traps us within the "wires" (the last word at the end of both line 4 and 5), and the unusual rhyme scheme supports the sense of containment the poem describes.