Molasses supplementation

Key messages

  • Molasses alone only provides energy. Mixing in urea improves the protein content.
  • Supplementation with molasses will increase pasture intake. Stocking rates will need to be adjusted.
  • Urea must be completely dissolved if being fed to cattle to reduce the risk of urea poisoning.

Cattle supplementation plays an important role in Northern beef production systems where a high percentage of cattle are grazing native pastures in a highly variable rainfall climate. Molasses based mixtures are widely used, especially in those districts within a reasonable distance of the sugar mills. In the Northern Territory and Western Australia, high transport costs of molasses mean that other energy supplements such as locally grown grain may be cheaper.

Properties regularly using molasses mixtures need an efficient feed-out system including bulk storage tanks, mixer, troughs, truck or trailer for distribution, and reasonable roadways to allow delivery around the property.

Molasses by itself only supplies energy. To increase its nutritional value, molasses needs to be thoroughly mixed with urea (for protein content) to provide a balanced energy-protein supplement. This is commonly used in the dry season in Queensland.

Molasses-based supplements have a role in keeping weaners moving forward, spike feeding heifers and breeders, and in certain circumstances, finishing steers (production feeding). It’s suitable for all classes of stock including weaners over 100 kg in weight.

Be sure to pay attention to available pasture as molasses supplementation can result in more pasture being consumed. If stocking rates are not adjusted, the over utilisation may lead to reduced ground cover. Molasses-based supplements can be a very useful production tool, but will not replace good herd and grass management practices. At all times, it is vital to ensure adequate pasture roughage is available to livestock.

Proactive management will ensure stock numbers are decreased, or removed, before livestock run out of roughage.

Value of molasses as an energy supplement

Molasses is primarily an energy supplement, but is deficient in protein. Therefore, it is generally not suitable as a long-term, low-level supplement (e.g. like a dry lick) unless used as a carrier or attractant and intake is controlled and kept to a very low level (e.g. roller drums, lick blocks). Because molasses is not a balanced feed, it is usually of little benefit when it is not fortified with urea. When its energy is balanced with key nutrients, it becomes an excellent supplement for cattle.

  • Molasses is about 25% water (cereal grains are about 10% water).
  • On a wet weight basis, molasses has about two-thirds the energy per kilogram that cereal grains have. Molasses has 8.7 megajoules of metabolisable energy (MJ ME) per kilogram.
  • Molasses is low in nitrogen and high in sulphur. Therefore, a sulphur source should NOT be included in molasses-based supplements.
  • Molasses has high potassium levels and low sodium levels. Generally, salt is added.
  • Molasses is also low in phosphorus.

Main ingredients included in molasses-based supplements


Molasses is deficient in protein so it is necessary to add a minimum of 3-4 kg of urea per 100 kg of molasses (for the rumen bugs to be able to efficiently utilise the molasses). It is highly recommended to use prilled urea, not granulated urea, as prilled urea dissolves about four times as fast in a mechanical mixer. Molasses urea mixtures must be mechanically mixed for a minimum of 30 minutes depending on your mixer design; mixing for over an hour is a common practise. If the molasses is thin (fresh and warm), prilled urea should dissolve in less than 20 minutes in a mechanical mixer. It will take longer if the molasses is thicker.

Urea supplies 2.87 g of crude protein per gram of urea (46% nitrogen).

Protein meals

Extra protein may be required for young weaners for extra animal performance. Vegetable protein meals (copra,  palm kernel extract (PKE) and soybean meals) are commonly used.  The recommendation is to use the cheapest protein meal available. Adding protein meals to molasses thickens the mixture considerably, and necessitates reduction gearing on mixing equipment. Adding protein meals also increases palatability and intake.


Salt is added to rectify the low sodium levels in molasses. It also counters the high potassium content in molasses which tends to produce very loose dung. Salt is always added into the molasses, urea, and protein meal (MUP) mixtures which are designed to allow high daily intakes and performance. Flossy fine salt is best used in molasses mixtures.


Dicalcium phosphate (DCP) and technical grade monoammonium phosphate (MAP) are the most commonly used concentrated phosphorus sources included into molasses-based production supplements.

Rumen modifiers

Rumen modifiers increase feed efficiency; that is, cattle get added benefit from the same feed and include Rumensin® 100 Premix and Bovatec®. Rumensin® 100 Premix (active ingredient monensin) should be included at 500 g per tonne. Directions for use must be strictly adhered to because of potential toxicity of some of these compounds. Small amounts of these products will quickly kill dogs and horses. Including Rumensin® in young weaner feeds will prevent coccidiosis developing but is ineffective in treating animals that have already contracted the disease.

Common molasses mixtures

SupplementRecipeCattle class
M8U (Molasses + 8% urea)1000 kg molasses 1
87 kg urea
Cows & calves
First calf heifers
Steers & heifers
Weaners over 150kg
M8U + phosphorus1000 kg molasses 1
87 kg urea
10 kg phosphorus 2
Cows & calves
First calf heifers
Weaners over 150kg
M8U + phosphorus + Rumensin® 1001000 kg molasses 1
87 kg urea
10 kg phosphorus 2
Plus 500 g Rumensin® 100
Cows & Calves
First calf heifers
Weaners over 150kg
MUP (Molasses + urea + protein meal)1000 kg molasses 1
40 kg urea
60 -100 kg protein meal
10 kg salt
10 kg phosphorus 2
Plus 500 g Rumensin® 100
Weaners over 100kg
Growing & fattening cattle
MP (molasses + protein meal)1000 kg molasses 1
100 kg protein meal
Weaners under 150 kg
Roller drum mix 1150 kg molasses 3
225 L water
35 kg urea
2.5 kg Gran-am
Suitable for 100 head of cows for a week (aiming to get 50 g per head per day urea intake)
Roller drum mix 2 45 L molasses
90 L water
14 kg urea
1 kg Gran-am
Suitable for 40 cows (or 80 yearlings) for a week
1Approximately 740 L
2 DCP, kynofos, MDCP or 6.4 kg technical grade MAP or Liquifert® P or equivalent per tonne of molasses
3 Approximately 110 L

M8U (molasses plus 8% urea)

M8U is a common supplement for survival/drought feeding, spike feeding pregnant heifers and cows, and keeping young stock growing slowly during the dry season. The 8% urea content is designed to regulate intake by making the mixture quite bitter.  It is an excellent crisis supplement to prevent deaths in all classes of cattle when there is adequate dry feed available. Cows will eat up to 2–3 kg/day in the late dry season, weaners may eat less than 1 kg/day. Much higher intakes have been recorded at times.  It is an expensive supplement option during the dry season compared to dry supplement formulations. Controlled mating and herd segregation by pregnancy status should be considered to minimise breeder numbers that regularly need M8U.

M8U plus phosphorus

This mixture with the added phosphorus can be fed during the dry season to wet cows and first calf heifers to replace some energy, protein, and phosphorus going out in their milk. It’s also suitable for weaners and steers that are grazing pasture that may have positive weight gain during the dry season e.g. seca stylo paddocks.

M8U plus phosphorus plus Rumensin® 100

The addition of Rumensin® here is claimed to improve digestive efficiency but at the low diet quality and poor animal performance in the typical dry season where M8U is being used, this is questionable. Higher levels of Rumensin® inclusion (up to 2 kg per tonne molasses) have been used in an attempt to restrict intakes of M8U in very dry years, and it’s usually successful for a short time but eventually, cattle can get back to high intake levels over 3 kg per day.

MUP (molasses plus urea plus protein meal)

MUP is regularly used for feeding weaners over 100 kg and is often cheaper per kilogram than alternative concentrates. Adequate infrastructure is needed though to handle feeding large numbers of weaners.

Include Rumensin® right from the start of feeding if coccidiosis is a risk. It is advisable to keep weaners in separate management groups (e.g. under 100 kg, 100–120 kg, and 120–140 kg). Good quality hay also needs to be fed at the same time. For cattle classes over 140 kg protein meals can be replaced in part or completely with cracked grain if it’s a cheaper option.

All cattle on MUP rations must have a roughage-grass supply as well. Intake levels of MUP will vary with available pasture quality. With low quality pasture, animals will eat up to 1.8% of their body weight of MUP per day (500 kg animal eats 9 kg/day).

MUP mixtures are used to grow/fatten suitable cattle classes for live export or the meatworks. The standard MUP recipe can be boosted with extra protein meal/grain/vegetable oil to bolster energy and protein levels and improve daily weight gain.

Similar to feedlotting, producers need to have a handle on daily intakes, and costs versus animal live weight gain, to ensure an economic result. In North Queensland, cattle being fed under this system, are ideally targeting boat trade or fat cattle markets late in the season when suitable cattle supply is shrinking and prices are rising.

Daily live weight gain will vary widely depending on the quality of the MUP ration, the class and weight of cattle and the quality and availability of dry grass, hay or roughage being grazed. Most feeding operations will be aiming for at least 0.6 kg/day live weight gain and, in numerous feeding trials, there have been records of over 1 kg\day live weight gain. The use of hormone growth promotants (HGPs) will improve daily animal weight gain.

MUP can be used in preference to M8U when there is very little dry feed available to cattle. It can stop deaths in crisis situations. Intakes for breeders are usually at least 4–5 kg/day and often about 1.5% of body weight.  In crisis situations, cattle may need to be fed roughage as well to meet animal welfare standards.

MP (molasses plus protein meal)

Straight molasses-protein meal mixtures can be used for young weaners 100-150 kg when the property doesn’t have access to a molasses mixer for dissolving the urea. But if intake levels are too low these young cattle will not be getting adequate energy-protein intakes per day for reasonable daily live weight gain, and producers need to change to a good (12 MJ energy, 20% crude protein) pellet or crumble type supplement.

Feeding methods

Roller drum mix

Roller drum mixes were a very common, safe way to feed out urea during the dry season, but have largely disappeared because of the cost of mixing gear and feeding out. High maintenance costs on mixing gear, vehicles, roads, and roller drums have seen a big move over to the use of dry supplement urea based loose licks.

Example recipes are provided in the table above. A mixer must be used to dissolve the urea into the water and molasses. To introduce cattle to roller drums start with a 50/50 mixture of molasses and water. Urea levels then need to be built up over several weeks or 4-5 mixes. If wet cows and/or heifers are being fed with roller drums and phosphorus needs to be added, tech grade MAP or phosphoric acid are the only suitable products.

Lick blocks

Many blocks incorporate molasses, usually as an attractant, or to bind the ingredients together.

Feedlot rations

Up to 17% of the ration can be molasses.

Horse supplement

Molasses can also be used to supplement horses. An example of a horse mix is molasses + protein meal + DCP + salt in the ratio by weight of 100:10:1:1. Horses on poor feed eating about 3 kg/day of this supplement will be kept in good working condition. Rumensin® must not be added as it is toxic to horses.

Unlike in cattle, straight molasses can still be a useful supplement for horses; therefore, protein levels can be lower than indicated above. Horses won’t gorge this like grain supplements, thus eliminating the potential of founder.

Targeting the right animals

As is the case with all molasses feeding, it is important to target animals in which a biological and economic response can be expected. Examples include:

  • Spike feeding only mid-late pregnant heifers and cows, not those which are empty or early-pregnant.
  • Targeting molasses to cattle close to marketable range.
  • Discontinue feeding where a response is not occurring.



Urea toxicity is rare when at least 8% urea is dissolved in molasses.

The risk of urea toxicity is reduced if mixes with high levels of urea (e.g M8U) are kept in front of cattle at all times. Intermittent feeding increases the risk of gorging, and therefore toxicity.

Urea toxicity and molasses bloat are less likely if cattle are introduced to 8% urea on day one and graded up. Starting cattle at lower levels may result in gorging. Gorging will result in deaths, when the level of urea is in the range of 3 to 8% in molasses-urea; a trap when introducing it to hungry cattle.

Rain on well-mixed M8U is almost invariably not toxic. However, if rain does fall on M8U, the water should be bailed off. Do not mix it into M8U as cattle may drink the mix and deaths may occur.

Undissolved urea concentrates in the top layers of the molasses. Add rainwater to the top of the mix and the urea will concentrate becoming lethal to the cattle that drink it.

Symptoms of urea poisoning include muscular tremors, frothing at mouth, drunken gait, weakness and collapse, and violent struggling before death. Death is usually quick with the animals found close to supplement troughs. Administer treatments quickly if symptoms are observed. Dose the animal with 4-8 litres of a 50/50 mixture of vinegar and water.


Two syndromes can occur with molasses, both when there is very little other feed for cattle to eat: molasses toxicity and molasses bloat.

  1. Molasses toxicity
    The flow rate through the rumen is so slow that Vitamin B is destroyed. Essentially, the syndrome is a vitamin B deficiency and presents as ‘molasses drunkenness’; i.e. the animals stagger around blinded. Treatment with either a Vitamin B injection, or green feed (e.g. lucerne), is usually spectacularly successful.Prevention is simply achieved by adding salt (at 1%) to the mixture, and providing extra dry matter, even if it is a small amount of low-quality roughage. Both the salt and roughage will increase the flow rate through the rumen, thereby denying the opportunity for breakdown of all the Vitamin B.
  2. Molasses bloat
    The rumen blows up with the formation of a foam. Cattle can go down and die from respiratory failure, simply because of the pressure on the lungs. Treatment for molasses bloat is the same as the treatment for standard bloat.Prevention is the same as for molasses toxicity, and is very effective. Bloat often occurs when cattle have a rapid intake of a molasses-protein meal mix after a period without feed, e.g. when intakes are being controlled by intermittent feeding.

Molasses feeding equipment and logistics


  • On-farm storage is vital. Storage requirements depend on the availability of molasses from suppliers, and the rate at which it is fed out. Water tanks are suitable for molasses storage if they are heavy duty, lined or reinforced. The base must be very sound, particularly for fibreglass tanks.
  • Molasses is heavy and very corrosive. Metal tanks will corrode at the storage line due to condensation and formation of weak acids. To minimise the damage caused, keep tanks filled, especially outside peak supplementation periods.
  • Cement tanks corrode and start to leak below the storage line. Avoid corrosion by lining the tank with a resistant coating before filling.
  • Molasses has a storage life of many years providing it is not contaminated with water. Water contamination leads to rapid fermentation and spoilage.


It is best to set up for gravity filling of storage tanks and gravity emptying into distribution tankers. Outlets of at least 150 mm are needed on storage and distribution tanks to ensure adequate flow rates. The outlet of the distribution tanker needs to be higher than the top of the troughs.

Remove the need to man-handle troughs where possible. For example, an outlet on the side of the distribution tanker allows it to be driven up beside the trough.

Molasses can be pumped using either a gear pump or a helical rotor pump. Using pumps not designed for the job will break. Augers are often used to feed components of molasses-based supplements into mixers. For ease of handling and efficiency, set up bulk handling facilities at truck-height.

Components for molasses supplement mixes are cheaper in bulk (i.e., 0.5 to 1.0 tonne bags), and may be easier to handle with equipment such as augers.

Contract bulk carriers (20–40 tonne semi or B-double loads) are often the most efficient for replenishing stores.

When a lot of supplement is being fed, it is probably best to have a large molasses mixer (e.g. 6 plus tonnes) mounted on a truck rather than a towed mixer which is generally smaller (e.g. 1.5 tonnes). Molasses mixers mounted on tippers are better as tipping the truck can substantially increase flow rate when the level in the tank is low.


Ideally, there should be sufficient troughs to necessitate feeding only once a week, or as long as it takes for a full tanker load to be eaten, whichever is the shortest period.

Provide enough troughs to allow equal access for all in a mob. Troughs should not be too high for the animals, especially calves.

Unless troughs are on concrete or very compacted areas, the dirt around them will be dug out. Therefore, the troughs need to be shifted regularly.


Plan well. Transport, storage, mixing, and feeding can be a logistics nightmare if planning is inadequate. One thousand breeders will eat about 15 tonnes (2400 gallons) of molasses and 1.2 tonnes of urea each week.


There are substantial capital costs involved in molasses feeding, particularly storage tanks, mechanical mixers, and troughs. The total cost of molasses-based supplements must be calculated delivered to the animal and often is high as for most energy concentrates.

As for any significant cost, the risk and financial return on feeding molasses-based supplements should be thoroughly evaluated before purchasing any infrastructure or supplement.

These notes are an introduction to molasses feeding to stock. More detailed information is available from your beef extension officer.

Written by Bernie English, Department of Agriculture and Fisheries.

The GrazingFutures Project reviewed this article. GrazingFutures is funded by the Queensland Government’s Drought and Climate Adaptation Program (DCAP) that aims to build drought and business resilience for Queensland livestock producers.

Recommended reading

Dry season management of a beef business: a guide to planning, managing and supplementary feeding, 2021, Queensland Department of Agriculture and Fisheries.