LR cannot output a Slideshow in a file format playable on most DVD players. You will need to use DVD authoring software to convert the LR .MP4 video file to a compatible format DVD disk. The DVD disk format has much lower resolution (720 x480) than your computer screen so not the best choice for viewing your pictures.
The LR slideshow .MP4 video file (1080p) is playable on most Blu-ray players. The file can be copied to a USB drive, SD memory card or DVD disk depending on what media the Blu-ray player supports.