The weeks leading up to calving and the weeks following calving can be extremely challenging for dairy cows. One of the most obvious stressors during this time is the shift from gestation to lactation and the sudden and dramatic nutrient demand for milk production that accompanies this shift.

Vitamin D is routinely supplemented to dairy cows to support a variety of physiological functions, such as mineral homeostasis and immune activity. Once absorbed, vitamin D is converted to 25-hydroxyvitamin D [25(OH) D] (calcidiol) in the liver and enters the circulating pool.

With increased pressure to reduce greenhouse gas emissions from all sources, agriculture must play a part by improving efficiency of the system and reducing emissions.

The Eighth Revised Edition of the Dairy NRC (National Research Council), now called NASEM (National Academies of Science, Engineering and Medicine) was published in December 2021, replacing the previous version published in 2001. The new book has a chapter dedicated to transition cow nutrition.

In 2021, the National Academies of Sciences, Engineering and Medicine (NASEM) published the 8th Edition of the Nutrient Requirements of Dairy Cattle (NRC). As with past publications, the NASEM 2021 was developed based upon the foundation of previous editions of the NRC publication and important updates reflecting scientific advances in nutrition and feeding programs for dairy cattle since the last publication in 2001.