Allowing a cow to successfully transition into lactation means reducing stress in both the dry and fresh periods. Part of limiting stress is providing the right balance of nutrients for a cow’s body to meet its changing needs during this transition.
On an episode of the Penn State Extension “Bovine Banter” podcast, Heather Dann from the W.H. Miner Institute discussed what a cow needs during the dry and fresh periods. More specifically, she honed in on how we can meet the requirements of both far-off and close-up dry cows.
Far-off cows — those more than three weeks out from expected calving — don’t have a lot of nutrient requirements, but that doesn’t mean we can ignore them. This is a time to focus on maintaining animal health and preparing them for lactation. A less nutrient-dense diet is sufficient, but Dann emphasized that we have to watch intake during this period. It is easy for cows to overeat during the far-off period and gain too much weight, raising the risk for early lactation problems. She advised feeding diets high in forage to help control how much cows eat.
On the other hand, close-up cows require a more nutrient-dense diet to support the rapid growth of the fetus that is happening during this time as well as the cow’s imminent transition into lactation. We achieve this by formulating close-up rations with less fiber and more digestible nutrients, protein, minerals, and vitamins, Dann said. As cows near calving, dry matter intake will naturally decline, so we need to provide a ration that encourages consumption.
When a farm does not have enough dry cows at one time to justify formulating and delivering separate far-off and close-up rations, a one-ration approach can be effective. If this is what your farm requires, Dann said the diet needs to align with the energy needs of the close-up cows more. A moderate energy level is advised so that cows are not gaining excess weight prior to calving. Vitamin and mineral levels should also be balanced on more of a close-up cow level. Be sure the ration also has adequate fiber to help control intake and encourage rumen health.
While feeding one ration to all dry cows may result in providing a more expensive ration than necessary to the far-off cows, if it is the best option for the farm, it is more critical to meet the needs of the cows closer to entering the milking herd.
Heifers and fresh cows
Rations can also get complicated if bred heifers are housed with dry cows because these animals are still growing themselves as they prepare to calve for the first time. Dann said this dual demand means heifers want more energy, protein, vitamins, and minerals. When they are comingled with older cows, feeding one ration with a slightly higher energy and protein content can be a good compromise between the needs, she said. Just be sure to monitor that the higher energy doesn’t cause metabolic problems for the mature cows.
Once an animal calves, Dann noted that an effective fresh cow diet should encourage intake, which can be a concern if a cow is dealing with metabolic issues. We accomplish this with a balance of fermentable carbohydrates, the right amount of neutral detergent fiber (NDF) that fills the gut but doesn’t limit intake, and sufficient metabolizable protein. Particularly for fresh cows, slug feeding can lead to subacute rumen acidosis, so we want to encourage several small meals throughout the day by providing a palatable, consistent ration that is regularly available.
Stressors all stack on top of one another like building blocks, Dann concluded. Don’t let a poor dry period and fresh cow nutrition be contributing factors to early lactation problems.
