Explain Please how the hay was 28% moisture.

Was it fairly early and baled just as the hay reached 28% moisture? In which case you could have had 40% moisture in the stems and leaves that were 14% Moisture.

I have baled hay around 10 am following the hay being as dry as pop corn at sunset the stems being about 12% moisture and the leaves being even drier. With the night dew the stems are about the same but the leaves are in the 30% range and it all baled very well. With out using any preservative.

This syatem allows Us here to start baling when the hay is an average 22% moisture. Nothing exciting. about an hour later we can shut off the preservative.

Damp leaves dry stems bales well. Damp Stems and Dry Leaves results in a bundle of moldy stems.

Actually I have not used my preservbative tank now in 10 years. Here being in reasonably flat Prairie country where the night humidity goes to 70% and the day Humidity goes to 20 to 30%

Seldom will we have a Night humidity (dew) less than 70% or a Day humidity less than 20%.
I like to bale when the evening before the hay was as dry as popcorn.
HERE is 31º N with no irrigation so we start baling alfalfa in Late March to April and bale nothing in July or August.  If we had irrigation it might be different, as In late July we seldom have enough Humidity to bale even at night. 

Just an example how baling conditions vary in this country.  

A few years ago  ( 25  ) there was a major blow up between a Michigan Forage Specialest and a NM Forgae Specialest.  
Both were correct, for their Climate.