SOURCE: Odo of Cheriton's' Latin fables are available in Hervieux's edition at GoogleBooks, and there is a delightful English translation by John Jacobs: The Fables of Odo of Cheriton.
This is fable 73 in Hervieux's edition. This is not in the classical Aesopic corpus, but Perry does list in his medieval appendix as Perry 623.
READ OUT LOUD. Choose which marked text you prefer to practice with - macrons or accent marks - and read the text out loud until you feel comfortable and confident. Then, try reading the unmarked text at the bottom. It should be easy for you after practicing with the marked texts. :-)
MACRONS. Here is the text with macrons:
Hircus semel factus est servus Asinī, et vīdit eum simplicem et humilem. Ascendit Asinum et voluit equitāre. Asinus īrātus ērexit pedēs anteriōrēs et cecidit rētrō super dorsum suum, et Hircum oppressit et interfēcit, dīcēns: Sī Asinus est dominus tuus, nē equitēs ipsum.
ACCENT MARKS. Here is the text with ecclesiastical accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Hircus semel factus est servus Ásini, et vidit eum símplicem et húmilem. Ascéndit Ásinum et vóluit equitáre. Ásinus irátus eréxit pedes anterióres et cécidit retro super dorsum suum, et Hircum oppréssit et interfécit, dicens: Si Ásinus est dóminus tuus, ne équites ipsum.
UNMARKED TEXT. Here is the unmarked text - after practicing with the marked text that you prefer, you should not have any trouble with the unmarked text:
Hircus
semel factus est servus Asini,
et vidit eum simplicem et humilem.
Ascendit Asinum
et voluit equitare.
Asinus iratus
erexit pedes anteriores
et cecidit retro super dorsum suum,
et Hircum oppressit et interfecit,
dicens:
Si Asinus est dominus tuus,
ne equites ipsum.
IMAGE. Here is an illustration for the story (image source) that actually shows a goat on a donkey!