“Goldilocks” Meets NASEM 2021:
Controlled-energy Diets for Dry Cows
Optimizing nutrition during the dairy cow’s transition or periparturient period is an ongoing challenge, with knock-on effects resulting from how she was fed during the entire dry period. New guidance in NASEM 2021 offers greater control in dry cow diet formulation.
“We still have too many transition-related diseases,” says Professor James Drackley at the University of Illinois, “such that more than 30% of cows have at least one clinical disease during the first 21 days in milk.”
Drackley also notes that post-calving metabolic disorders reduce dry matter intake (DMI) by 8-10% and increase body weight (BW) losses. Transition problems lead to fat cows at next calving, which interrupts what researchers call “the high fertility cycle.”
He endorses “best practices” throughout the dry period that help sustain a smooth transition:
- Optimize cow comfort (minimizing stressors and inflammatory challenges)
- Prevent hypocalcemia (using anionic salts)
- Meet metabolizable protein (amino acid) requirements
- Support the cow’s immune system, control inflammation and oxidative stress
- Target 3.0 BCS (body condition score) for calving
In particular, he warns against overfeeding energy in the far-off dry period. And the close-up diet should be intermediate in energy to the far-off and fresh diets.
Using NASEM 2021
Drackley notes that the new DMI equations show…
For far-off dry cows (>3 weeks prepartum):
- DMI at 1.8-2.0% of BW
- Negatively correlated with dietary NDF
For close-up dry cows (<3 weeks prepartum):
- DMI starts decreasing ~2.5 weeks prepartum
- Rate of decline negatively correlated with dietary NDF
He adds that, at about week 1 prepartum, DMI is about the same for all NDF (1.65% of BW).
