Hopefully she is climbing back up in her health and production.
Did you happen to change her feed just before she got sick?
I wasn't quite clear on how much grain you were feeding.You said---
2 gallons each the pellets and cob. 1/2 gal soybean meal. 3 gal barley. 2 flakes alfalfa and 1/3 bale grass.
It sounds like you were feeding 2 gal pellets 2 gal cob 1/2 gal soybean, and 3 gal barley.
Am I correct on that?
If so that would be a total of 7 --1/2 gal of concentrates per feeding. which sounds a bit on the high side from what I am used to.
I don't know if there is any connection, but I have seen on a dairy farm that I used to work on, there was an accidental over feeding of grain ( I was NOT involved in the "boo-boo")
and it shut off the milk production just like shutting a tap off, and these were very high producing holsteins that ended up giving only a couple of squirts of milk. When their acidosis calmed down, their milk production came back to normal, or near normal. With the over feeding of grain also came lots of mastitis.
You said you were feeding barley. Barley is a very "hot" feed, which we have fed when fattening 4-H steers, but a local feed specialist told me that when feeding lots of barley one needs to give cattle something that is high is calcium like beet pulp, as barley is low in calcium.
I can't ever recall seeing cattle "steaming" when being fed barely, but other people who have fed it swear up and down that cattle when fed high amounts of barley, literally start sweating, because it is a "hot" feed.
Maybe talk to a local feed specialist at your local feed store, or maybe government ag specialist and see what they recommend for lactating cattle in your area and dryland situation.
Our climate and situation is quite different, so would have different feed requirements than you.
Hope things work out..