La. Code Civ. Proc. art. 1457

A. Any party may serve upon any other party written interrogatories to be answered by the party served or, if the party served is a public or private corporation or a partnership or association or governmental agency, by any officer or agent, who shall furnish such information as is available to the party. Interrogatories may accompany the petition or be served after commencement of the action and without leave of court.

B. During an entire proceeding, written interrogatories served in accordance with Paragraph A shall not exceed thirty-five in number, including subparts, without leave of court. Additional interrogatories, not to exceed thirty-five in number including subparts, shall be allowed upon ex parte motion of any party. Thereafter, any party desiring to serve additional interrogatories shall file a written motion setting forth the proposed additional interrogatories and the reasons establishing good cause why they should be allowed to be filed. The court after contradictory hearing and for good cause shown may allow the requesting party to serve such additional interrogatories as the court deems appropriate. Local rules of court may provide a greater restriction on the number of written interrogatories.