Research Note

Optimal Transition:
Prepartum to Postpartum Dietary Strategy

Much recent research on transition diets has focused on reducing postpartum subclinical ketosis and hypocalcemia. Meanwhile, other work has further refined transition nutritional strategies, focusing on key periods — far-off, close-up, fresh, early lactation. What are the key takeaways?

Five areas “really matter”, says Cornell’s Dr. Tom Overton.

1. Far-off: Overton says that “well-implemented” controlled energy diets in dry cows help to improve postpartum metabolism and dry matter intake. Work at the University of Illinois, Cornell University and others led to lower postpartum non-esterified fatty acids (NEFA) and ketones such as ß-hydroxybutyrate (BHBA), which are markers for negative energy balance.

He notes that controlling dietary energy also involves providing adequate protein. In Cornell studies using three different dry period dietary energy strategies, researchers adjusted formulations to provide about 1300 g/day of metabolizable protein (MP).

Researchers compared a controlled energy prepartum diet (bulky, high fiber, 100% of energy requirement) versus a high energy diet (150%) and a ‘step-up’ (controlled energy followed by 125% during close-up). The controlled energy diet yielded lower NEFA and BHBA without affecting milk production or dry matter intake (DMI).

“Importantly,” Overton says, “glucose and insulin concentrations remained higher postpartum in the controlled energy group, confirming the Illinois work. The fresh cow needs glucose for normal immune cell function while insulin prevents excessive breakdown of adipose and muscle tissue.”

Adapted from “Moisture content of high straw dry cow diets affects intake, health, and performance
of transition dairy cows”, C. D. Havekes, et al., 2020

Controlled energy total mixed rations incorporate more fiber, often using straw or hay combined with corn silage and a grain mix. However, cows are good at sorting. Overton points to University of Guelph studies that show how reduced particle size and added moisture can decrease sorting, increase prepartum DMI, and help maintain postpartum ruminal pH. 

2. Close-up: “There are two distinct prepartum dietary strategies to decrease postpartum hypocalcemia,” Overton says. “Decreasing the dietary cation-anion difference (DCAD) and supplementation using a calcium-phosphorus binding compound like synthetic zeolite A both have been shown to be effective in improving calcium status.” See his paper from the 2025 Cornell Nutrition Conference.

3. Close-up & fresh: As Cornell studies and others show, metabolizable protein supply plays an important role during both close-up and fresh periods. Overton adds that amino acid balancing during the transition period improves metabolism and performance.

4. Postpartum: He notes that greater diet fermentability postpartum promotes better performance and metabolic status. Inadequate forage neutral detergent fiber (NDF) can degrade ruminal health, while too much NDF can limit DMI.

5. Opportunities: Overton points out that certain nutrients — like rumen-protected choline, chromium, and biotin — are likely to be “conditionally essential” in the transition cow. Certain additives, including monensin and yeast products, can help sustain ruminal balance during transition.

Questions?

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