If you’re not already including a liquid feed such as molasses or a molasses blend in your rations, summer is a good time to realize the benefits.
Liquids feeds can improve the palatability of a ration, increase intake and reduce ingredient separation and potential sorting. There have been concerns that the rapidly degradable sugars in liquid feeds can lead to milk fat depression. But if fed correctly, liquid feeds can actually help to maintain or increase butterfat.
In a trial recently published in the Journal of Dairy Science, a liquid feed composed of molasses and corn steep liquor was fed at 3.25% or 6.5% of the dry matter. The liquid feed and soyhulls replaced corn in the ration to reduce the non fiber carbohydrate (NFC), while maintaining total starch and sugars. Basically, sugar replaced starch in the rations. Starch was reduced from 27% to between 18% and 21% on the liquid feed diets, while total sugar went from about 4% up to almost 9% of the dry matter. Forage NDF was maintained at 21%, and NFC was reduced from 41% to 38% of the dry matter with the liquid feed.
Milk fat test on the liquid feed diets didn’t differ from a control ration with no liquid feed, and cows gave significantly more fat corrected milk when fed 3.25% liquid feed on the lower NFC diet. Feeding 6.5% liquid feed increased dry matter intake, but not milk production. Milk fat percentage was not affected by the high liquid feeding rate, even when Rumensin was included in the diet.
I include a liquid feed in most of my diets. In most areas of the country, liquid feeds are very cost effective, especially when compared to current market corn prices. They are also a convenient and safe way to include NPN in the diet and are an excellent carrier for fat and certain minerals and vitamins.
Reference: Firkens, et al., Journal of Dairy Science, 91:1969-1984
Rick Lunquist is an independent nutrition and management consultant based in Duluth, Minn. You can contact him at siestadog@aol.com.
