Es - why would the slave masters keep slaves ignorant of their own birthdays?
only impertinent people need to know when they are born.
if a slave knew of his birthday, he would demand a paid holiday.
focusing on the birthdays of slaves would call attention to the older
slaves.
keeping personal information secret from slaves meant that they were not
considered human, therefore, more easily controlled.

Keeping personal information secret from slaves meant that they were not

considered human, therefore, more easily controlled.

Explanation:

In the American colonial slavery era,  the constant abuse  and the social status difference between races was easily notable, this kind of actions, like not inform o commemorate a  single day to determined slave, was made basically  to keep the rights, and will of them at a minimum expression.  This means that for the masters was important to remove from the slaves conscience the fact that they can be treated better or recognized by an action, ¨special date¨ or have benefits of a normal human being.

The subordination was a key point for the masters, so having their slaves in a high grade of repression and submission, allowed them to have way more control over the black people.

the answer is a quran

fertile good for trade etc