Since glucose is needed to produce energy less fat might be mobilized, a desirable condition. No increase in milk production was observed, however. Fat generally is not added to dry cow diets. However, many cows are switched after calving to rations that have added fat. This is acceptable but may not be ideal.
Cows tend to reduce intake with added fat to maintain a constant energy intake.
This may delay cows from reaching maximum dry matter intake and optimal rumen function. Some larger dairy herds have a post-calving ration to be fed for 10 to 14 days. This ration is high in protein, minerals, and vitamins, but contains no added fat. The goal is to get cows eating with a nutrient dense ration and then switch them to one with fat. Smaller herds probably can not justify this extra group.