“We know that adding sugary liquids to rations can reduce ration sorting and as a result increase rumen efficiency and ultimately milk yields,” says Bronwen Pihlwret, QLF nutritional advisor. Yet she adds that molasses-based liquids are often overlooked as a cost-effective way of utilising rations.
“With many farmers having access to good quality silages this winter, the addition of molasses will be an efficient way of making the most of forages and therefore could potentially save farmers money if they can reduce concentrate inputs,” says Bronwen.
Sucrose sugars from molasses are known to increase rumen efficiency by altering the balance of rumen microbes and volatile fatty acid production. “As a result, rumen pH is often found to increase, creating a more efficient rumen environment, resulting in increased fibre digestion and improved forage intakes.
“And, as well as offering a source of energy for efficient rumen processing, the addition of liquid sugar has also been proven to increase neutral detergent fibre (NDF) intake,” says Bronwen.
Sugar comes in many shapes and sizes, for example Bronwen explains that molasses based liquid feeds contain, sucrose, glucose and in some cases lactose. Further to this to achieve optimal microbial protein production a target of between 5-7 % of a cows’ DMI is required from fermentable (six carbon) sugar in the diet.
She adds that studies have confirmed that feeding a six-carbon sugar found in molasses increases DMI compared to a five-carbon sugars, such as xylose or ribose which are found in fermentation co-products like wheat syrups, processed feeds and silages.
“It goes without saying that maximum dry matter intakes are needed if producers are to achieve consistent high milk yield and quality milk composition,” says Bronwen.
Further research has shown the profound effect that sugars can also have on milk quality.
“The addition of molasses can lead to improved milk fat and protein (See Table 1). The research identified that milk fat increased by 8% when cows consumed a molasses-based liquid feed within their ration compared to a control diet.
“Not only were positive constituent results seen, cows also produced more milk per kilogram of feed consumed,” says Bronwen. She adds that this indicates that forage optimisation was achieved without the need for extra concentrates in the ration, proving that sugar can provide an economical solution for maintaining margins and increasing milk from forage.
Reducing ration sorting
However, in order to maximise the full potential of forages, producers need to ensure that optimal rumen conditions are maintained.
“When feeding a TMR it’s vital for rumen health that long-fibre particles cannot be easily sorted away from the rest of the ration,” explains Bronwen.
“This is likely to delay consumption until later in the day or cause them to be refused completely and induce a risk of sub-acute rumen acidosis (SARA).”
SARA is subtle condition in high yielding dairy herds that is caused by a drop in rumen pH. “When the pH falls below 5.6 for an extended period, SARA can be induced,” says Bronwen. She adds that optimal rumen pH conditions should fall between 6.0 and 6.4.
“To help prevent SARA, and avoid economic losses, farmers should be presenting their herd with a well formulated TMR which includes high-quality forages that have been cut at optimum chop lengths,” says Bronwen.
Research has shown molasses-based liquid feed markedly reduced the sorting of long particles. “In the trial over two thirds of cows that were fed a TMR containing a liquid feed consumed more long particles compared to just over half of control cows.”
“By ensuring long-fibre particles are presented to cows in less than 5cm lengths, and by having adequate moisture in the form of molasses based liquid feed, ration sorting can be reduced significantly,” says Bronwen.
She explains that cows are sensitive to unpalatable feeds and will actively sort for preferable taste and texture. “Naturally a fresh palatable feed will encourage intake, however it’s important that cows are consuming all parts of the ration to achieve its full nutritional benefit.”
Including a liquid molasses in a TMR will not only increase the palatability of the ration but will also help to combine particles which means cows will eat a more balanced diet, resulting in a more stable rumen environment,” advises Bronwen.
Increased NDF intake
Liquid feed plays a key role in dairy rations, as cows consume more NDF when they cannot sort longer particles out of forage.
Bronwen explains that forage NDF varies widely in its degradability in the rumen. “Forages are unique compared with other dietary ingredients because they provide long fibrous particles that are retained in the rumen for longer, as a result they tend to ferment more slowly than smaller feed particles.
“By adding a molasses-based liquid to a forage based TMR, it will aid rumen efficiency and reduce sorting which will help increase NDF intake,” says Bronwen.
She adds that this is supported by research published in the Journal of Dairy Science . The study found that by feeding a molasses-based liquid feed as part of a silage-based TMR, dry matter intakes (DMI) were increased significantly, along with NDF intake. As a result, milk fat yield and milk protein yield increased significantly compared to the control diet.
“The research supports the view that if you increase DMI and maintain optimum rumen conditions, not only will you achieve optimum milk yield and quality but you will also increase feed efficiency whilst reducing production costs,” adds Bronwen.
Increased rumination time
Research has proven that feeding a QLF molasses-based liquid feed can increase rumination time by 25 minutes per day.
“The additional rumination time is significant as it influences DMI and stimulates the production of saliva secretion which may also improve rumen function,” says Bronwen.
“And as already identified, we know that by increasing DMI producers will see a cost-effective increase in milk outputs,” she adds.
“To achieve an ideal milk composition and maintain margins it’s important that quality forage is utilised as the main source of energy. The multiple benefits of adding a liquid sugar to rations can help to deliver milk yield potentials without the need for large amounts of concentrates. This makes liquid sugar a cost-effective choice when supplementing winter rations.”