animal feed technology

Sugar blocks – a new generation animal lick technology

Published on: 5/10/2010
Author/s : P.George Kunju John (Animal Feed Consultant)


Live stock feeding has been progressed today to a conversion efficient technology from the ancient concept of converting non-edibles and low nutrient feed stuffs to good animal products like milk, meat and egg. Often it was noted that the ruminant livestock production is almost entirely dependent on feeds consisting of fodder and crop residues. These feeds are generally of poor quality, usually deficient in protein, energy and minerals. To improve production, the efficiency of utilization of the available feed resources can be optimized by the use of feed technology treatments and supplementations that provide the deficient nutrients. The above technology therefore is mostly applied for ruminant nutrition as the conversion efficiency is noted very poor in those animals. The bulk of their ration is fibre as their digestive system is equipped with the fibre digestion more than protein. They derive protein through microbial fibre fermentation thereby the synthesis of microbial biomass utilizing the soluble nitrogen, volatile acids and ATP. Even though the above digestive process is low efficient owing to higher nutrient loss in the system yet it has been established widely. The development of Urea Molasses Mineral Block is the latest tool in feed technology to improve the fibre utilization in ruminant animals.

Urea Molasses Block

It was recognized that when animals are offered a low-nitrogen, high fiber roughage such as rice straw (RS), one of the critical nutrients is fermentable nitrogen (N) available to rumen microbes (ARC, 1984). The use of urea/molasses blocks is a convenient way for avoiding excessive intake of urea, and will ensure an almost continuous supply of ammonia-N (PJG Kunju & Leng 1981; Preston, 1986). Urea/molasses block feeding yielded positive results in many parts of the world (PJG Kunju, 1986; Hadjipanayiotou et al., 1993; Chen et al., 1993).  The advent and application of UMB in the field was aimed at manipulating the rumen fermentation of fiber thereby derive more dietary energy and microbial protein from the ration. The microbes in rumen control the rumen fermentation and they depend on their nutrients on the cattle ration. Their major essential nutrients are nitrogen, carbon, ATP and co-factors. When the UMB supply them those nutrients as per the requirements, they may proliferate in rumen and degrade fiber most efficiently. (30g N/kgFOM see ARC, 1984). This was found more efficient and economical than the mechanical treatments. The molasses blocks are usually kept in front of animals to make it accessible all the time for licking. The main control on intake of blocks for bovines and ovine is the ammonia concentration in the rumen fluid. It has been found to have a bio- rhythmic reaction in rumen for the intake of block. When the rumen ammonia level falls below 50mg/ltr of rumen fluid the animal will have an urge to lick the molasses block. In the same way when the level rises above 200 mg/ltr there will not be any tendency for licking. (PJG Kunju, 1982). In order to get the above axiom in operational the molasses block should contain urea or ammonium salts as nitrogen source. However, to utilize the ammonia thus ingested by the animal ATP should be readily available. The bottom line is the molasses blocks should contain a minimum of 40% molasses and 5% urea. Once the licking is biologically controlled, it would help to create a healthy rumen flora in side the rumen. This means larger population of micro flora. It could cause the larger colonization of microbes on the feed particles, which can ultimately, digest. (See PJG Kunju 1982) The innovation of this novel technology in National Dairy Development Board (NDDB), India in 1981 caused its wide application through FAO/UN into various parts of the world. NDDB had patented this technology in 1983.

The Plant developed for the manufacture of UMB in India consisted of a surface scraped heating vessel to squeeze out water molecules from molasses. The shearing paddles rotating at opposition circles fill the dry feeds in the vacuum of moisture displacement through scraped heating. The gelling of mixture with Sodium bentonite make a high viscous hot dry substance which is flow able due to the trapping of steam in layers. The mixture filled in moulds hardens to solid block while cooling. The high pressure steam <7 bar needed to elevate the temperature of molasses to 120 deg C and the high tork of electric energy needed to mix the dough  increased the cost of production over 50%. The labor handling of hot dough for steam removal and moldings further made the process intrinsic. The obsolete technique used to pack the new product and store beyond the shelf life of the product came out of an engineering skilled plant utterly put down it aesthetically and commercially. The developers put no efforts to modify the packing to preserve the product and technology. 

In order to improve the technology two methods were tried like microwave technology to remove the moisture from molasses and to coat calcium/potassium soaps on the dried mixture to solidify the block which will be non-hygroscopic, hard to texture and well balanced in nutrients. However, the above technology development was terminated in the ACIAR/NDDB project for unknown reasons. Further more the lick feed technology was a new concept to Indian farmers. The farmers orientation was inefficient to encourage them and the pricing was kept at par with cattle feed. (See J Patel, IRMA, and Anand). However, the concept of feeding microbes was received with great welcome in several parts of the world. In order to make it cheaper several low cost methods were evolved like CaO, cement etc. It is interesting to note the development of 500 3kg blocks per day by NDDB where in it is setting up large scale feed plants in India. ( Garg, Mehta & Singh 1998) 

The commercial block plants with larger capacities are set up in many countries. In USA itself, there are several patents to the production of molasses solid blocks. The UMMB recently developed in NDDB and FAO (cold process) essentially target to the feeding of urea. The earlier invention of UMMB, which was patented, was a rumen manipulator to enhance the microbial protein synthesis, enable protein bypass by maintaining the rumen ammonia concentration in rumen, encourage the saliva production and prevent pica character in cows (Kunju & Leng 1986). The hygroscopy, melting and deshaping could be prevented by proper process technology. The cold process examined and adopted the solidification capacity of CaO on storage ignoring the pH of blocks, possible interferences in mineral composition in rumen and interferences in ammonia concentration in rumen.

The molasses block preparation (cold process) suggested by NDDB is not trying to exploit the 'solid to solid' phenomenon noticed in sugar. The large-scale plants heat molasses to reduce the viscosity and melt sugar before mixing with dry feeds and metallic slats. (see US Patents).The approach was to reduce the moisture by adding brans, gelling with bentonite and hardening with CaO. The pH is adjusted with Phosphoric acid where the cost could be acceptable. The fibre digestion improvement through urea incorporation is helping the utilization of low nutrient fibrous feeds. The bottom line is UMMB has been marked a feed supplement for straw feeding where as the technology could be utilized for in a better way to manipulate rumen fermentation, bypass nutrients, fibre digestion and microbial proliferation.

Sugar Blocks.

The large proportion of UMMB is molasses (45 - 60). The high viscous molasses makes the mixing of brans, minerals and protein meals energy demanding. The poly saccharide/glu mixed with high ash content makes the hardening slower. The molasses with 59% organic matter has only 46-48% total sugar as invert. Therefore, the dietary energy availability from molasses is very low like brans. Again, the coupling of molasses with brans and high ash reduce the dry matter digestibility. The low efficiency of 'solid to solid' phenomenon of sucrose in molasses makes the block more hygroscopic. Eventually the molasses blocks remain as supplement feed to low yielding cattle, fattening sheep and goat and beef.

Sugar syrup has been developed as an animal feed at Al Khaleej Sugar Co, Dubai (PGK John, 2006). It is used in animal ration for the following reasons: 

  • Increases the palatability of the feed.
  • Improves the dry matter digestibility
  • Bypasses sucrose in rumen
  • Reduces the dustiness of the feed
  • Inhibits the mould formation on the feed
  • Stops insect infestation on storage
  • Use as a binder for feed pelletisation
  • Increases energy density of the ration
  • Masks the less palatable ingredients.
  • Substitutes the grain in feed formula
  • Improves the fiber utilization my ruminant animals 

Table 1. A typical analysis of Sugar syrup





Crude Protein


Crude fat


Crude fibre




Total Sugars
















Met. Energy  MJ/kg


TDN for ruminants


Copper       mg/kg












Folic acid




Pantothenic acid



2.6- 5.0









 Sugar syrup is the first liquid separation from sugar crystallization. This could be called 'High Test Molasses' or 'A

Molasses. The high content of sugar, low ash and low viscosity are good attributes for the production of animal licks. 

Sugar Block Process.

Sugar syrup could be sprayed at 70 deg C as a mist into the mixer chamber where in the other ingrediants could be mixed using a tulip shaped paddle mixer. This would coat the sugar syrup evenly onto the feed particles. The process would evaporate moisture from sugar syrup. In case higher percentage of sugar syrup is added, the hot air could be passed through the mixer. The mixed material coming out of the mixer would be almost dry ( 12-14%) moisture. The mixture could be pressed into solid blocks in hydraulic press. The pressed blocks are packed in cardboard boxes of 5, 10 or 20kg sizes and shrink packed. 


The formula could be varying according to the type of animals. A formula for dairy cow is shown below:

  • 1. Sugar syrup 60%
  • 2. Protein meal 5%
  • 3. Urea 15%
  • 4. Phosphoric acid 2%
  • 5. Salt 3%
  • 6. Corn flour 10%
  • 7. Mono calcium phosphate 5%
  • 8. Calcium carbonate 4%
  • 9. Trace minerals 1% 

Different sugar blocks could be prepared for other animals like horses, camels, sheep and goat. 


In order to manufacture 100 MT blocks ( 10,000 blocks of 10kg) the plant may need the following components.

1. Sugar syrup storage tank     1000 M3

2. Process tank with oil heating      4 M3

3. Mixer                                        2 M3

4. Drive   15 HP                            1                                   

5. Sprayer nostles                        10

6. Sprayer pump                        4 HP 7 bar pressure

7.  The Storage bin                     10 M3

8.  Conveyors/augurs

9. Hydraulic press                         100 MT/sq inch

10 Shrink packing                         2


The plant is a batch process with 1000kg per batch. The process time is 10 minutes per batch. In order to make the operation more pragmatic it would be appropriate to install the unit in a feed mill.        


Fig 1. Sugar syrup Coater for BLOCK Production. 

The Sugar syrup coater shown on the fig 1 is of continuous process line. However, it could be made as batch process and opened to a process silo to hold the mix before blocking.


The Sugar Blocks could be made non-hygroscopic, hard to texture but readily soluble on saliva, can be hanged on rope like salt lick. The use of right formulation can make the block to supply soluble nitrogen to the level of rumen ammonia concentration, supply bypass protein, bypass sucrose, fatty acids, minerals, vitamins and pro biotic. The release of sucrose could be bypassed partly and a part of sucrose and the reducing sugar could be fermented in rumen for the supply of ATP. The solid texture of block avoid melting it like molasses blocks. The low viscosity of Sugar syrup will enable homogenous mixing of protein meals, starch, fatty acids and other nutrients. The sucrose would inhibit the mould formation on blocks. Because of the high purity materials used in Sugar syrup it would be a new technology animal lick for high yielding cows too. The general reputation of UMMB as a feed supplement for crop residue feeding construe the technology low cost and none sophisticated. The advent of Sugar Blocks would bring sea changes in Lick feeding technology in animal nutrition. 

Dr. George K John graduated in 1967 on Bachelor of Veterinary Science from University of Kerala, India. He then began to work as a veterinary officer at Amul dairy, the largest dairy cooperative in Asia. He carried out extensive research in rumen manipulation and bypass protein after his post graduation from University of New England, Australia. He developed Urea Molasses Block, bypass protein feed, broiler goat and several feed supplements. Currently he is actively engaged in freelance consultancy to feed plants, Livestock farms, universities in India and abroad.
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