In this article, I put together direct quotes from a few popular press publications on feeding sugars to dairy cows. The articles were written by different field dairy nutrition experts, who expressed their views on feeding sugars based on their own experience feeding cows.
The Relationship Between Sugar and Milk Protein
By Rick Lindquist, Nutrition Professionals Inc.
Dairy Herd Management, April, 2021
- “Over the years, I’ve noticed that my clients that fed rations inherently higher in sugar and soluble fiber generally produced milk with higher protein.”
- “Many diets are 10% sugar, with starch in the low 20’s, forage percent in the 30’s and much of the NDF coming from high sugar byproducts.”
- “Cows grazing lush pasture may be consuming over 20% sugar. Sugar ferments to butyric acid and doesn’t end up as lactic acid so it’s rather benign when it comes to acidosis.”
- “Dr. Mike Van Amburgh describes how fermentable sugar and soluble fiber increase microbial yield, which can increase milk protein. More sugar promotes more protozoa, which are efficient at digesting fiber. Protozoa can make up 20% of microbial yield. Dr. Van Amburgh agrees that our current field models do not consider protozoa contributions to microbial protein, and milk protein predictions.”
- “Recent published research showed that milk protein yield was greatest when total dietary sugar was between 6.75 and 8% of dry matter.”
Specific sugar types and sources for dairy cows
Mary Beth de Ordanza, Paradox Nutrition LLC
Progressive Dairy, March, 2021
- “Added sugar often increases milk fat percentage and/or milk fat yield. This may be because butyrate generated from sugar is used for milk fat synthesis. Also, if sugars moderate rumen pH, one would expect an improvement in milk fat percentage. Finally, sugars may promote the normal fatty acid biohydrogenation pathway, decreasing the amount of the trans-10 isomer of the 18:1 fatty acid implicated in milk fat depression.”
- “In a recent analysis of published research, it was found that supplemental dietary sugar increased yield of milk, 3.5% fat-corrected milk and milk true protein. Fat-corrected milk (3.5% FCM) increased from 71.2 to 74.4 pounds per cow per day with 5% to 7% added dietary sugar. Higher-producing cows had greater responses to added dietary sugar. Cows producing more than 73 pounds per day of milk produced 4.7 pounds per day more 3.5% FCM with 5% to 7% added dietary sugar. However, cows producing less than 73 pounds per day only responded with 1.7 pounds per day more 3.5% FCM.”
Could dietary sugar be your next ration adjustment?
Mary Beth de Ordanza, Paradox Nutrition LLC
Hoards Dairyman, December 2020
- “Sugars are digested and used by the rumen microbes very rapidly. Studies show that adding sugars to diets almost always reduces the amount of ammonia in the rumen. This suggests that sugars help the rumen microbes capture and use more of the nitrogen in the diet, especially nitrogen coming from rapidly digestible sources such as the soluble protein in silages.
- Dietary sugars can help to control rumen acidity (increase pH) via a few different mechanisms. First, if more sugars end up as part of the rumen microbes, a lower percentage of the total rumen degraded carbohydrate is converted into fermentation acids. Second, because sugars are rapidly available, they are more apt to be converted into the storage polysaccharide, glycogen, by rumen bacteria and protozoa, slowing fermentation to control rumen acidity. Finally, dietary sugar is more likely to be converted to butyrate. The production of butyrate generates only one hydrogen ion, while the production of propionate from starch generates two hydrogen ions. So, if sugar is substituted for dietary starch, its fermentation to butyrate would help to reduce rumen acidity. Butyrate also stimulates the rumen epithelial cells, improving absorption of volatile fatty acids from the rumen to reduce rumen acidity.
- Consider supplementing sugar in locating dairy diets to achieve 6% to 8% total diet sugar for optimum rumen function and performance. Generally, 1.5 to 2 pounds per cow per day of supplemental sugar would be needed to achieve 6% to 8% total sugar in typical U.S. diets. Higher-producing cows would be expected to have more positive responses to added dietary sugar. Liquid sugar sources have the added benefit of potentially reducing TMR sorting.