KMS 3rd cut is all grass with no seedheads and very few stems if any. The 2nd cutting they have right now is nice hay but lots of stalks (still has a decent amount of leaf). Oxbow doesn’t distinguish between cuttings so if you order Oxbow online, you may get 1st or 2nd cutting. Small Pet Select has a softer 2nd cutting right now but it does have thin stalks and alot of short pieces in it.
1st cutting hay is normally very stalky with lots of long seedheads and less leaf than 2nd cutting. It has the most fiber because of the stalks. 2nd cutting is normally a softer hay, still has stalk but has more leaf than 1st cutting, and has shorter seedheads. 3rd cutting is normally all leaf. I say “normally” because the weather and timing of the harvest will affect how tall the hay grows, when the farmers can cut the hay (the longer it grows the taller and stalkier it will be), and whether or not they even getva 3rd cutting.
Some bunnies (mine included) don’t like the stalks as well so many online distributors focus on 2nd cutting for bunnies.