H Bheekhee


Agricultural Research and Extension Unit





Molasses is a major by-product of the sugar industry in Mauritius and is still under-utilised for livestock production because of legislation and handling problems. A combination of urea, molasses and other feed ingredients can be used to produce urea-molasses multinutrient blocks (UMMB) that can be fed to livestock as a supplement. The main objective of UMMB supplementation is to provide a constant source of degradable nitrogen throughout the day, to promote growth of rumen microbes in ruminants fed poor quality forage. Studies with cattle, goats and sheep elsewhere indicate that supplementation with UMMB resulted in increased milk yield and growth rate when no other form of supplementation was given. In Mauritius, studies have shown that UMMB can be utilised as a supplement in the smallholder dairy cattle production system as well as in the deer production sector.




Ruminant livestock production is almost entirely dependent on feeds consisting of fodder and crop residues. These feeds are often of poor quality, usually deficient in protein and minerals. To improve production, the efficiency of utilisation of the available feed resources can be optimised by the use of supplements that provide the deficient nutrients. Generally for such purpose, concentrates such as cottonseed cake and cowfeed which are high in protein are used as supplements. The purpose of supplements is to provide nutrients that are deficient in the basal diet and nutrients needed for production. Some of these supplements can sometimes be manufactured using locally available ingredients and agro-industrial by-products.


Molasses which is a major by-product of the sugar industry in Mauritius, is a good, palatable and cheap source of energy for ruminants. Use of liquid molasses by small farmers, however, is very limited due to problems related to transport, storage and legislation. One strategy to get over this obstacle and increase the use of molasses is through the manufacture of urea-molasses multinutrient blocks (UMMB). The technique is to mix the different ingredients in a container and to pour the mixture in moulds to solidify into blocks. Major advantages of using the blocks are their convenience in terms of packaging, storage, transport and ease of feeding. Blocks can thus provide an avenue to maximize the use of locally available feed materials such as molasses and bran for feeding ruminants, thereby reducing the use of high cost concentrate feeds. This strategy of producing UMMB has been proposed by the International Atomic Energy Agency (IAEA) in order to develop affordable and sustainable supplementation packages for improving the productivity of smallholder farms.




Investigations at AREU have led to the formulation of UMMB using locally available ingredients namely sugarcane molasses, urea, common salt and wheat bran. Other ingredients such as minerals, vitamins and a source of good quality protein like cottonseed cake or soya bean meal are imported but readily available on the local market. Cement is used as a binding agent. Studies conducted in Canada and USA on the utilisation of cement and its by-products as minerals for animals did not reveal any negative effect when fed up to a maximum of 3% of the total daily dry matter intake (Aarts et al, 1990).  The proportion of ingredients used in the manufacture of two sets of UMMB, A and B, using two different amounts of molasses is shown in Table I. The level of cement as a binding agent is adjusted to obtain blocks of good texture and hardness that regulate intake by the animals. To obtain a good setting, cement needs a minimal quantity of water, just enough to make a paste for proper mixing.


Table 1  Proportion of ingredients used in the manufacture of UMMB at Curepipe Livestock Research Station



% by weight

 (fresh basis)



Molasses (>80 Brix)






Mineral Mixture



Common Salt



Cottonseed Cake






Wheat Bran




      Ratio water:cement is 2:5


All ingredients should be weighed accurately before mixing. Mixing can be done either manually for small quantities, or mechanically using a concrete mixer, or a horizontal paddle mixer for large quantities. The sequence in which the ingredients are mixed is very important.  Urea is first added to the molasses and thoroughly mixed. All lumps should be broken down to ensure proper mixing and to avoid toxicity problems  when fed to animals.  Mineral mixture, cottonseed cake and half of the amount of salt are then added, while mixing continuously.  The remaining half of the salt is mixed with cement and water to make a paste, which is then added to the molasses mixture and thoroughly stirred to obtain a consistent paste.  Wheat bran is added last, little at a time and thoroughly mixed until the product is homogeneous.  This product is then ready to be placed in moulds.



Moulding and drying


Moulds can be made of wood, plastic, iron or carton boxes, which may be of any shape and size. A plastic sheet placed in the mould or an oil film prevents the block from sticking to the wall and allows easy removal from the mould. Once the mixture is placed in the mould, it should be left in a well-ventilated room to set. The mixture takes about 48 hours to set, after which the blocks are ready to be utilised. For cattle, 10-kg blocks seem to be convenient.  Blocks wrapped in a plastic sheet or left in carton boxes can be stored in a dry place for several months. Table 2 indicates the chemical composition of the two sets of UMMB, A and B.


Table 2  Chemical Composition of UMMB (% fresh matter basis)





Crude protein



Crude fibre






Calcium (as Ca)



Phosphorus (as P2O5)



Ash (other than Ca and P2O5)



Carbohydrates, sugars, etc.




The dry matter (DM) content of block A is 77.7% and that of block B is 83.2%. The mean calculated metabolizable energy (ME) of the supplements A and B are 10.9 and 11.0 MJ/kg DM respectively.





UMMB must only be fed to post-weaning, growing or adult ruminants and never to monogastric species or to pre-ruminant calves, kid goats, lambs and deer fawns because of urea toxicity problems. Since blocks are supplements they should always be used with a minimum quantity of roughage. Blocks are introduced gradually in the diet of ruminants during a transition period of about 2 weeks to enable the animals to adapt to the new supplement. Afterwards, blocks are offered to animals without any interruption. Blocks being palatable, are licked by animals according to their requirement, thereby regulating the intake of urea so as to ensure its efficient utilisation, without any risk of toxicity. The targeted daily intake by adult animals should be 700 g/head for cattle, 150 g/head for deer and 100 g/head for goats and sheep.





Consumption of UMMB depends on the type of fodder or roughage and concentrates in the diet as well as on the physiological state of the animal. The positive effect of UMMB intake on overall performance of an animal will be more pronounced on a low plane of nutrition, that is, a crop-residue or straw-based diet. According to Hendratno (1997), there is a significant improvement in body condition and reproductive performance as well as an overall increase in milk yield. Also, higher amounts of molasses may be utilised not only as a feed component but also as a vehicle for urea, minerals and rumen non-degradable protein to cater for nutritional deficiencies.





Another potential for UMMB supplementation that can be exploited is through the use of medicated blocks, for the control of pests and diseases. Animal species that can benefit from medicated blocks include deer, goats, sheep and young calves. In the deer sector, both the normal and the medicated UMMB can be used. These can prove to be highly advantageous especially in the extensive system of deer production where there is very little control over the animals.





AARTS G, SANSOUCY R and LEVIEUX GP.  1990.  Guidelines for the manufacture and utilisation of molasses-urea blocks. Animal Production and Health Division. FAO. Rome, Italy.


HENDRATNO C.  1997.  Development and utilisation of UMMB as a feed supplement for ruminants. Paper presented at the First Regional Training Workshop (AFRA) on Guidelines for developing supplementation packages. Morocco. March 1997.