Here's a slightly more detailed critique (what the hell, it's lunchtime). I've marked the feet with '|'.

To some|, in in|come-anti|cipation,

Four feet, not five. Third foot is a three-syllable anapaest (dum-dum-DUM). Fourth foot also has three syllables, but we can disregard the last one and treat '-ation' as a single syllable (this is sometimes called a 'feminine rhyme').

    Horse-bal|king at gates |is a small |debase;

Four feet again, two anapaests. It's spelt 'baulking' with a U. You don't mean 'horse-baulking', which would mean the act of baulking a horse, but 'A horse baulking' or 'To see a horse baulking'. There's no such noun as 'debase', and I don't know what it's meant to mean here ('disadvantage'? 'annoyance'?).

To me, |it seems |a memo|ry/fe|ar case|

Just about works as long as you pronounce 'fear' with two syllables, which most people don't.

    Over| the com|ing whip|-castigation.

Four feet - a trochee, two iambs and a dactyl (DUM-dum-dum).

To some|, the winn|ing jock|ey's elation

Four feet - three iambs and an anapaest

    Is the |highlight| of an| ended| horserace;

Five feet, every one of them a trochee. Seriously, look at this. The only way this is iambic is if you can read 'Is the highlight' and emphasise 'the' and 'light'.

To me|, the hor|se's bulged| veins and |scared face

Three iambs and two trochees. Usually you'd say 'bulging' veins and you wouldn't refer to a horse's 'face'.

    Un|dermine| the win|ners' cel|ebration.

I'll let you call this iambic, even though there's a syllable missing at the start.

I can't |condone| a pun|ter's desire|

Four feet, last one an anapaest.

    To gam|ble ra|ther than earn| a living,

Four feet, third one an anapaest. (And is that really why punters gamble? They can't keep at it for very long if so.)

    But can |acknow|ledge a joc|key's courage;

Four feet, third one an anapaest. Maybe you've invented a new metre.

I can't |see and |think as |a raced| sire,

Two trochees and one foot with a missing syllable - and what's a 'sire' in this context?

    Nor feel |the scrapes |hedges| are giving,

Four feet, one of them a trochee.

    But find |horses |choiceless in |their bondage.

Four feet: iamb, trochee, dactyl, iamb. Also, doesn't rhyme - when you're using feminine rhymes, the rhyme needs to include the stressed syllable as well as the trailing unstressed syllable, and 'cour-' doesn't rhyme with 'bond-'.

Summary: most of the rhymes are either bad or forced, and the metre's terrible - there are only two lines of iambic pentameter in the whole thing, and both of them are debatable.