ST. CLOUD, Minn. — Every dairy operation has many, many components that must work well and blend together seamlessly in order to have a successful dairy business. There is a lot to keep track of, and it’s important that nothing slips through the cracks, especially when it comes to dry cows. Dry cows do not benefit from a “one size fits all” approach when it comes to their nutrition, but there are some common practices to keep in mind.
Consider body condition score. Using the 5-point scale, cows at or above a 3.5 BCS at calving are more susceptible to metabolic disorders and mobilize more fat after calving. Late lactation BCS should be around 3.25 at dry off. There is research out of Illinois that found overfeeding energy for an 8-week period can lead to excessive internal fat and be harmful to cows. This is especially true during the transition period due to inflammation and impaired liver function. Internal fat is not always indicated in body condition score, and when thin cows are overfed, they can respond as if they were fat.
Observe cows regularly and watch for various symptoms. There are five key symptoms of overfeeding and/or excessive insulin resistance; large decreases in intake as a cow approaches calving, low intake or sluggish increases in intake in fresh cows, excessive body weight or BCS gain during the dry period, excessive body weight or BCS loss during early lactation, and higher incidence of subclinical and clinical ketosis and displaced abomasum.
There are two key components to dry cow nutrition that should help control BCS as well as body weight: maintaining dry matter intake through calving and optimizing nutrient intake and supply. Dry matter intake can be maintained, while energy intake is controlled by formulating diets appropriately for fiber and energy density. Typically corn silage-based diets provide too much energy. Controlled-energy diets typically incorporate low-energy feedstuffs such as straw, grass hay or hay crop silage. These feedstuffs allow cows to consume feed ad libitum without over-consuming energy.
Once dry matter intake is set, the diet can be formulated with protein feedstuffs to supply at least 1100 g/day of metabolizable protein. Meeting the protein requirements benefits immune function, mammary development and protein reserves. Protein reserves are used for metabolic functions in the first few weeks of lactation when the cows experience negative protein balance along with negative energy balance.
Dry cow nutrition and management are important to the success of any dairy business.
— Emily Wilmes, University of Minnesota Extension
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