Reason 1: Cows are naturally adapted to high-sugar diets. High-starch diets (greater than 28 percent) or high starch fermentability may depress ruminal fiber digestion, but high-sugar diets (6.5 to 8.5 percent) do not.
Pasture grass, grass hay and alfalfa hay are all high in sugar. Currently, dairy cows are fed large amounts of starchy grains, which can increase the risk of acidosis and other health issues. Feeding molasses-based liquid supplements helps to increase ration sugar content, which can reduce the risk of acidosis compared with high-starch diets.
Reason 2: Rations with excessively high starch content and fermentability reduce rumen pH and may reduce neutral detergent fiber (NDF) digestibility and trigger milkfat depression. On the other hand, feeding a high-sugar diet using molasses products can help maintain a higher rumen pH and has been shown to improve milkfat yield and help correct milkfat depression.
Reason 3: Feeding a high-starch diet may depress ruminal butyrate and acetate production. On the other hand, feeding a molasses-based higher sugar diet can promote the production of ruminal butyrate and acetate, two key short-chain fatty acids contributing to milkfat synthesis.
Reason 4: Recent research found de novo fatty acid production has a strong positive correlation with the production of milkfat and protein. De novo fatty acids are the fatty acids synthesized within the mammary gland from short-chain fatty acids, which are produced by the rumen fermentation of fiber. When feeding diets containing 7 to 10 percent total sugar, ruminal butyrate concentration is increased. Butyrate is used as a substrate for de novo fatty acid and milk component synthesis. Instead, starch fermentation may reduce rumen pH, which does not facilitate de novo fatty acid synthesis.
Reason 5: Molasses-based sugar products do not contribute to rumen fill. Inclusion of molasses-based sugar products typically helps increase feed intake. Every pound of additional intake usually converts to 2 pounds of milk yield.
Reason 6: Molasses-based products stick the total mixed ration (TMR) together and reduce sorting. Sorting causes variations in TMR consumption, rumen pH, manure consistency and milk components. Many cows develop acidosis and lameness because of sorting. Feeding 4 to 5 pounds of molasses-based sugar supplements can reduce sorting and promote more consistent rumen fermentation patterns, increase milk components and decrease vet costs. On the other hand, most cows sort for starchy grains, resulting in harmful effects on health and production.
Reason 7: Molasses-based liquid supplements can especially help drive feed intake in pre-fresh and fresh cows due to increased palatability and stickiness of the ration. Excessive starch fermentation may depress intake and cause fat cows. By stimulating the dry matter intake of fresh cows, molasses-based supplements help to reduce fresh cow health issues and increase start-up milk.
Reason 8: Molasses-based sugar supplements can help improve feed digestibility, while corn starch reduces total tract digestibility. In addition, using molasses-based liquid supplements allows for the feeding of higher forage diets, which are more economical and beneficial to rumen and cow health.
Reason 9: Molasses-based sugar products have little to no shrink, while starchy grains have shrink. Shrink accounts for 10 to 15 percent of feed loss on a commercial dairy. Dairy producers can reduce feed shrink by feeding molasses-based liquid products. Some molasses-based products allow for the delivery of protein, minerals, vitamins and additives through liquid feeds. Once mixed into liquid products, expensive minerals, vitamins and additives can be delivered to each individual cow much more consistently in a TMR without shrink.
Reason 10: High-sugar diets reduce the risks from poor management factors, while high-starch diets exacerbate the risks. Dr. Charlie Sniffen recommended different feeding rates of starch and sugar based on different cow management and environment factors. If the stocking density is high and bunk space is limited, you need to feed more sugar and less starch. This is consistent with the concept that poor feeding environments exacerbate ruminal dysfunction and acidosis, and that replacing some starch with sugar can reduce the harmful risks caused by starch. 
Katie Raver is a dairy technical services manager for Quality Liquid Feeds.
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Kai Yuan
- Dairy Technical Services Manager
- Quality Liquid Feeds
PHOTO: Molasses-based products stick the TMR together to reduce sorting, which in turn promotes more consistent rumen fermentation patterns, increased milk components and decreased vet costs. Photo provided by Kai Yuan.
