Transition cow diets have been the focus of considerable research the last few decades. However, 90 percent of that research has been done on dry cow or prefresh rations, says Ric Grummer, University of Wisconsin-Madison professor emeritus and current ruminant technical director at Balchem.
"Maybe we have missed the boat by not putting the emphasis on the postfresh cow," Grummer noted in his presentation at the Professional Dairy Producers of Wisconsin's Transition Cow Workshop last week. "In reality, it is easy to meet the energy requirement of a dry cow," he said.
It is the postpartum cows that do not consume enough energy to meet requirements and are likely to experience negative energy balance, he explained. "Negative energy balance is blamed for a lot of things, including poor immune response, poor reproduction and more metabolic disorders," Grummer said.
Dry matter intake is the key. Negative energy balance is more closely related to depressed dry matter intake than high milk yield. From the research that is available, it appears cows in early lactation respond with more milk production when diet energy density is improved by adding NFC (nonfiber carbohydrate) and lowering NDF (neutral detergent fiber).
"We should do whatever we can to get energy into those cows. Feed forages that are highly digestible, and avoid forages that are not digestible," Grummer advised.
More protein is also needed due to the onset of lactation. Protein is different than energy, Grummer said, as there are limits to how much corn and fat can be fed, but there are no real limits to protein.
Still, there is pressure to reduce dietary protein because of its effects on the environment and the wallet, Grummer explained. "I would advise against going too low. Tightening protein may be a good strategy for a majority of cows, but cows in early lactation will be cheated with just one diet."
He recommends a 21-day postfresh pen or ration that would allow for a brief period of feeding high crude protein. In general, a more nutrient-dense ration in early lactation will provide a fresh cow with more of her daily requirements in every bite, even if dry matter intake is down.
The author is an associate editor and covers animal health, dairy housing and equipment, and nutrient management. She grew up on a dairy farm near Plymouth, Wis., and previously served as a University of Wisconsin agricultural extension agent. She received a master's degree from North Carolina State University and a bachelor's from University of Wisconsin-Madison.
