By the time fat reaches the mixer wagon it has been rendered or crushed, transported, stored and blended, and each of those steps has consumed part of its protection. The consequences are lower metabolizable energy from the fat fraction, loss of vitamins A, D and E, reduced palatability, and peroxides that the animal has to handle metabolically. In transition dairy cows and under heat stress, that additional oxidative load arrives exactly when the animal has least capacity to absorb it.