You would need to create an automation that runs a script when a record is updated (or created depending on how the record is made).
It would need to split the dates in column C, then do the math for each one, then create an array of the results, and plug it into column D (Age).
As far as I know there is now simpler way to do it in Airtable.
Hello @Andres_Hidalgo , we've built an app that you may find helpful here.
The app will generate a script that you can add to your "Run a Script" automation action, and the script will split the long text from multiple cells in the first table and create records in the second table, as well as linking the records together.
It does not matter how many data fields you have, so if you have the fields "IndividualAnchors1", "IndividualAnchors2", "IndividualAnchors3", "IndividualLink1", "IndividualLink2" for the same record, the app will still work fine.

This will help you to create one record Lot with the date in another table. You can then create a formula field to calculate the difference between the created date and birth date, and then use a rollup field to display the differences back in your original table!