I found this poem in the collection Philosophia Patrum edited by Julius Wegeler.
Cum Stercore Noli Certare
Hoc scio pro certo, quod si cum stercore certo,
Vinco seu vincor, semper ego maculor.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are two words in this poem that are not on the DCC list:
maculō, maculāre: stain, pollute
stercus (stercoris, n.): dung, manure
certō -āre: decide by contest; fight, compete, vie
certus -a -um: sure, fixed; certē, certainly, surely
cum: with (prep. + abl.); when, since, although (conjunction + subj.)
ego meī mihi mē: I, me
hic haec hoc: this; hōc: on this account
nōlō nōlle nōluī: be unwilling
prō: for, on behalf of, in proportion to (+abl.)
qui quae quod: who, which, what / quis quid: who? what? which?
sciō -īre -īvī/-iī -ītum: know
semper: always, ever
sī: if
sīve seu: whether; sīve . . . sīve: whether . . . or
vincō vincere vīcī victum: conquer