I realised the value in feeding open cows for a while in the first of our dry years. Because I was buying hay I wanted to sell every open ASAP. The problem is our vets assistant accidently poured 2. As they both had raised steer calves I just threw them in with the replacement heifers. The market went up and they gained a bunch. Even if I had bought feed for them the profit would have paid my whole yearly vet bill.