You buying this?

[hhw]

Slugs are usually the result of overfeeding, which most of the hobby is prone to. By feeding small prey items like ASF, it's more difficult to overfeed and thus slug rate would go down.

Most prey items are at their most nutritious at the medium adult phase. Pinkies to weanlings, their bone structure hasn't yet developed, and with limited movement, they are much higher in fat. Conversely, as they get on the older side, their calcium content goes down and fat content goes up again. Medium adult is generally the ideal life stage for nutritional value. For an ASF, that's generally in the 30-50g range, whereas for rats, that's in the 75-150g range.

Rats have thicker fur than mice or ASF's, which could potentially be harder to digest in some species but not an issue at all with ball pythons. Rats also have more fat and less calcium. It's a reasonable proposition that ASF's would be more nutritious, but no way that's going to be anywhere near 100% more nutritious. Fat is also not necessarily a bad thing for a younger, growing snake.

Medium adult rats are a pretty ideal size for adult ball pythons, but multiple medium adult ASF's would be a much more natural diet. But it really shouldn't matter all that much.