La. Stat. tit. 9 § 5136
The parties to a mortgage of either immovable property or movable property, or both, or the parties to a security agreement under Chapter 9 of the Louisiana Commercial Laws (R.S. 10:9-101, et seq.), may designate a keeper of the property to be appointed pursuant to R.S. 9:5137 by expressly naming or identifying in the mortgage or security agreement the person who is to serve as keeper or by describing the method by which he is to be selected. The parties may designate the mortgagee, or secured party, or his agent as the keeper or may permit the mortgagee or secured party to name the keeper at the time the seizure is effected. If the designation of the keeper by the parties to the mortgage or security agreement is not made in the original instrument, it may be made by any other instrument executed by them, either concurrently with or subsequent to the act of mortgage or security agreement, which in the case of a mortgage on immovable property shall be by an instrument duly acknowledged by the parties in the presence of a notary public and two witnesses.
La. R.S. § 9:5136