Enhancing Ruminant Health
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The function of molasses and sugars in the ruminant diet has been studied for many years. Molasses was first extracted from the sugar refining process in the mid-19th century. Since then, refiners have been looking for markets for molasses, and animal feed has been an important component of that.

Like research in many areas, even after a couple of generations, while there are aspects that have become well known, there are others less well known. We still do not understand what form of “sugar” is most beneficial and in what nutritional circumstances.

Included below are a selection of articles and research studies relating to sugar and molasses, from basic considerations to an atomic level view.


Dry Cow Molasses Study - December 2019

Sweeten up your dry cow diet.

A recent study done at the University of Guelph demonstrated that adding molasses-based liquid feed to dry cow diets improves feed intake before calving, and stabilizes reticulorumen pH across the transition period.

Why feed molasses?
  • Incidence of ketosis in early lactation is related to the degree of negative energy balance (NEB) experienced at that time
  • How we feed cows in the weeks leading up to calving may play a significant role in the severity of NEB experienced after calving
  • Controlled-energy dry cow diets are commonly fed, however, these diets are often high in straw which has low digestibility and is easily sorted
  • Liquid molasses is highly palatable and known to encourage feed intake, while decreasing feed sorting

Research Questions
Does supplementing a high-straw dry cow diet with a molasses based liquid feed...
  • Improve dry matter intake (DMI) pre-calving?
  • Maintain dry matter intake post-calving?
  • Improve rumen function?
  • Discourage feed sorting?

University of Guelph Research Trial
Studied 40 Holstein dairy cows fed 1 of 2 dry cow diets, for a 6 week dry period:

20 Control dry cows (C) No molasses addition to TMR
20 Liquid Feed (LF) dry cows 2.0 kg/cow/d as fed (1.0 kg/cow/d DM basis) of molasses-based liquid feed added to the TMR

Diets contained, on a DM basis: corn silage (C=41%, LF= 39%), wheat straw (C=36%, LF= 33%), and dry cow supplement (C=23%, LF= 22%).

In Summary, adding liquid molasses to a high straw dry cow diet:

  • Improved DMI across the dry period
  • Reduced feed sorting during the dry period
  • Stabilized reticulorumen pH around the time of calving

For access to full article, view links below



Havekes, C., T. F. Duffield, A. J. Carpenter, and T. J. DeVries. 2020. Impact of molasses-based liquid feed supplementation to a high-straw dry cow diet on feed intake, health, and performance of dairy cows across the transition period. J. Dairy Sci. 103:5070-5089. https://doi.org/10.3168/jds.2019-18085