Fresh Cow Nutritional Needs

Fresh Cow Nutritional Needs
3/27/2018

Replacing lost nutrients and trace elements

The loss of nutrients and trace elements such as calcium, magnesium and potassium for dairy cows after calving has been well documented. Because most metabolic issues occur within the first two weeks of lactation, it is important to quickly provide supplemental trace elements.

A fresh cow’s requirement for calcium triples after calving. Boosting blood calcium levels to prevent ketosis is critical. Much has been written on how soluble sources of calcium increase blood calcium for six to 10 hours after dosing.

Calcium chloride represents a source of highly soluble calcium and has a 95 percent absorption coefficient. Another approach to prevention is oral calcium supplements around calving. A study in the Journal of Dairy Science discusses how calcium chloride may be particularly beneficial as an oral supplement because it is a more potent acidifier than other anion sources.

While calcium plays an important role in fresh cow recovery, other trace elements play essential roles for the reduction of metabolic diseases. Two of these trace elements are magnesium and potassium. Insufficient absorption of magnesium and an increased amount of potassium from the transition period can also contribute to hypocalcemia.

A 2008 Veterinary Journal study describes how meta-analysis has revealed the important roles of dietary calcium, magnesium and phosphorus as well as the duration of exposure to the pre-calving diet in milk fever control strategies.

Harnessing live yeast to accelerate the rumen

Active dry yeasts are increasingly used in ruminant nutrition as feed additives to improve feed efficiency and performance and, at the same time, to prevent health disorders. Animal science studies have shown them to be particularly useful in high-producing ruminants whose digestive microbial balance can be altered by high dietary energy input. Overall, the results show live yeast supplementation tended to improve meal patterns and rumination, rumen temperature and milkfat production.

Another important factor influencing dry matter intake of fresh cows is jump-starting the rumen mucosa and papillae, in both length and texture. This is important, as the papillae typically lengthens and increases its surface area for absorption after calving. This, in turn, leads to the absorption of various nutrients required for energy and, ultimately, milk production.

This was profiled in a study by Nocek, Holt and Oppy in which live-cell yeasts were shown to exert a more direct and accelerated effect in the rumen, usually associated with oxygen scavenging or reduced fermentation rate.

In addition to overall health for the fresh cow, yeast supplementation during early lactation significantly improved dry matter intake, milk yield, crude protein digestibility and acid detergent fiber digestibility for cows. It has also been noted supplementation of live yeast increases milk yield and milk protein yield percentage without a significant increase in feed consumption.

A 2017 study in the Journal of Applied Animal Research showed a connection between greater milk and milk protein yields and improved rumen function due to feeding live yeast products.

In 2012, a study published in Journal of Dairy Science discussed how the addition of supplemented live-cell yeast in a high-starch diet increased total tract digestibility and tended to increase milkfat content. Additional studies have shown fat-corrected milk was 4 percent greater in live yeast groups, concluding live yeast supplementation to dairy cows improved the rumen environment in a way that increased dry matter intake, thereby enhancing productivity and efficiency.

Additional research has shown live yeast removes oxygen from the rumen, leading to increased anaerobic bacterial viability. Increased bacterial viability means greater microbial population turnover, cellulose digestion and microbial protein production, potentiating a greater influx of post-ruminal substrates essential for liver glucose production.

Using an effervescence bolus to improve bioavailability

Effervescent delivery technology presents some interesting opportunities to enhance bioavailability of critical nutrients. Effervescence is the formation and release of gas bubbles from a liquid by a chemical reaction. Effervescence increases the surface area within the digestive tract for key ingredients.

The result is increased absorption, speed of absorption and overall bioavailability. In addition, effervescent technology provides an ideal environment for any moisture-sensitive trace elements such as potassium.

Wrapping it up

Minimizing treatment and the time spent managing fresh cows can be costly. Getting fresh cows off to a good start is critical. The question is how to get fresh cows drinking, eating and producing more quickly. This is best accomplished by recognizing the importance of replacing lost nutrients and trace elements and by stimulating the development of fiber-digesting bacteria in the rumen to increase energy.

Nathan Upah for Progressive Dairyman Published February 2018

Tags: Nutrition, Transition Cows