What direction is the guard rail ? N/S  or E/W ?  Wonder what kind of shade it makes after about 6 pm. When it is hot and no wind blowing, sometimes cattle will use shade till dark. Anything that makes shade from 9 am to 4 or 5 pm, does not do much for late afternoon to evening time frame. Is the rail flat enough to throw shade later in the day ? Take its not yours, and you did not build it, so maybe you dont know.  ??