The cows have dropped 3 to 5lbs per day, so holding up awfully well considering the definite heat stress. I would have expected a drop of 10lbs/day or more if it were not for 100' of sprinkler hose overhead at the feed bunk & 4 new fans in the freestalls. Heck, without those things, we'd have cows dropping dead all over the place!
I'd say you are doing well under the circumstances. Last Week the Iowa Cattlemans association said over 4000 hed had died in this heat. And that does not take count on those since. This morning the National Weather Service said July was the hottest July since 1955 in Iowa.