Cane molasses blends can be a valuable ingredient in the formulation of optimal transition diets according to Georgina Chapman, technical support manager with ED and F Man.

“We ask a lot of our dry cows,” she said. “Within 150 days of being dried off, we expect them to achieve target body condition, regenerate udder tissue, calve down with no transition problems, settle into lactation, rapidly increase dry matter intakes and get back in calf again. Getting the diet right throughout the dry period is one of the biggest drivers of lactation profitability.”

She says molasses blends have fallen down the list of ingredients preferred in transition diets based on a perception of mineral imbalances but says they can play a valuable role in preparing the rumen for post-calving intakes while exploiting the benefits of straw based diets

To tackle the requirements of low energy density and assist with achieving the DCAB balance, straw based dry cow diets have grown in popularity, offering more control than grass silage-based rations.

“Straw is seen as a way to limit energy intakes to manage condition score and can also help maintain high rumen fill to prepare the cow for higher intakes post-calving. However, straw is fairly indigestible and as one of the aims of dry cow diets must be to prepare the rumen microflora in advance of post-calving intakes, including a high sugar molasses blend can play a significant role.”

She explains the sugar fraction in molasses is a blend of different sugars including sucrose and glucose which are the important six carbon sugars.

“They are more highly rumen fermentable and more effective at improving fibre digestion, increasing microbial protein production and stimulating rumen fungi, all of which are important in dry cow diets.”

She says cane molasses also has a significant impact on the rate of rumen fermentation. Sugars are rapidly fermented, and most will have been fermented within two to three hours of feeding. But trials show that the rumen fermentation remains more active long after the sugars gone.

“By promoting faster and more active fermentation, they will increase rumen throughput and so stimulate dry matter intakes. Sugars also have a positive impact on volatile fatty acid (VFA) production.

“Where sugars are fed, we see an increased production of butyrate in particular. Butyrate is a growth factor for the rumen epithelium and promotes more efficient nutrient absorption through the rumen papillae which is key during transition.

While molasses blends can help prepare the rumen pre-calving and improve the use of straw in diets, they have often been excluded from transition diets because they were thought to have a negative impact on DCAB balance, as disruption of this can increase the risk of milk fever.

She says the principle behind DCAB diets is that you can create the slightly acidic conditions in the blood which in turn promote calcium mobilisation from the bone and help prepare the cow for the huge increase in calcium demand at calving.

“The aim is to reduce the DCAB around three weeks ahead of expected calving, ideally so it is in the range 200 meq/kg to -200 meq/kg. Our new data shows many molasses blends have DCAB values which make them a realistic option for dry cow and transition diets (see table).

“Many nutritionists have avoided feeding molasses and associated products to transition cows due to concerns over Potassium levels and high DCAB increasing the milk fever risk,” she comments.

“However, with careful product selection, and balancing of mineral levels across the whole ration, high sugar liquid products can be successfully used for calving cows.”

ED and F Man’s Transition Cow Syrup is a high sugar blend to improve palatability of diets and promote dry matter intakes. The addition of magnesium chloride, which is an anionic salt, helps to counteract cations in the diet contributing to lowering the DCAB of the ration.

Glycerine is included as it is a high energy ingredient which helps raise the energy density of the blend. It is also very palatable and being low in potassium contributing to lowering the DCAB.

“Use of sugar based liquid feeds and Regulated Release Urea products can maintain palatability of high straw diets as well as improving the physical properties of the mix and so help prevent ration sorting while maintaining an optimal DCAB balance, helping cows transition smoothly,” Ms Chapman observes.

DCAB Values of molasses blends

Blend Name DCAB

(meq/100g DM)

Economol 34.99

Stockmol 20 47.29

Molale 55.91

StiMOLator 55.35

Pot Black 51.25

Regumix 42.72

Regumaize 44 29.60

Regupro 38 60.38

Glycomol 79.17

Transition syrup -251.83