USE OF SUGARCANE MOLASSES AS RUMINANT DIET
Molasses is highly palatable and an excellent source of energy. In addition to its use as energy feed, is also used in following ways.
1) As appetizer
2) To reduce dustiness of a ration
3) As a binder for pelleting 4) To stimulate rumen microbial activity and
5) To supply unidentified factors.
The quality of molasses is measured by its sugar content, which is expressed by the term Brix. Brix is determined by measuring the specific gravity of molasses. After the specific gravity has been obtained the value is applied to a conversion table from which the level of sucrose can be determined. As sugar content increases, degrees brix likewise decreases.
Cane molasses————
Cane molasses is a by-product during manufacture of sugar from sugarcane. From each ton of sugarcane approximately 25-50 kg of molasses are produced. Cane molasses must contain atleast 43% sugars and have a density of not less than 79.5 brix.
Sugarcane molasses is a viscous, dark and sugar-rich by-product of sugar extraction from the sugarcane (Saccharum officinarum L.). It is a major feed ingredient, used as an energy source and as a binder in compound feeds.
Sugar cane molasses is a rich source of sugars, is available in organic form, and may be a viable supplementation option to corn. As milk prices fluctuate and input costs increase, grazing dairy operations seek lower-cost feed alternatives to maintain or improve milk production while reducing feed costs. This has been most evident within the dairy sector, as cereal grain like maize prices have been traditionally high relative to conventional grain.
Cane molasses has been used as feed for livestocks for many years. Generally, cane molasses is in dry or liquid form and is practical source of dietary sugars for feeding to dairy cows .Cane molasses is a rich source of sucrose, seems to be a viable option as a source of energy and minerals. The main sugars in molasses are sucrose (65%), fructose and glucose. Molasses contains 50% sugar on an as fed basis and 70% of the sugar is sucrose. Cellulose, starch and sugars all end up eventually as hexoses. These hexoses then are metabolized to pyruvate which can be metabolized to acetate, propionate, butyrate or lactate. Ruminal conditions must exist where the majority of hexose is fermented to acetate, propionate, and butyrate but not lactate. The energy generated from this fermentation must be used for bacterial growth if sugars are to be used successfully in dairy feeding programs.
Cane molasses often costs less per day to feed than maize/corn, is energy dense, is extremely palatable .Cane molasses is categorized as concentrate. Ideally, a concentrate is that feed component which supplies primary nutrients (protein, carbohydrate and fat) at higher level but contains less than 18% crude fibre with low moisture. In general, concentrates are feeds that are high in nitrogen free extract and Total Digestible Nutrients (TDN) and low in Crude Fibre (CF). On the basis of the Crude Protein (CP) content of air dry concentrates, these are classified as either energy rich concentrates when CP is less than 18% or protein rich concentrates when the CP value exceeds 18%. In India, mainly there are three types of indigeneous molasses i.e., cane molasses, beet molasses and citrus molasses. The cane molasses is a type of energy rich concentrate from plant source i.e., sugarcane. It is often included in a ration to improve its palatability, improve rumen microbial activity, increase microbial protein synthesis. Thus, it can facilitate the reduction of dustiness in the ration or act as a binder for pelleting.
The addition of sugar to dairy cattle diets can be very positive. Trials have reported increased milk yield and milk fat percent or increased NDF digestibility.
About 70% of typical diets for lactating dairy cows consist of carbohydrates, of which 37% are structural carbohydrates (neutral detergent fiber; NDF), 30% starch, and 3% simple sugars (free glucose, sucrose, fructose, and other minor sugars). Although each of these fractions is made up mostly of molecules of glucose, the nature of the chemical linkages affects the rate and extent of digestion in the rumen. About 45% to 60% of the NDF, 50% to 60% of the starch, and 100% of the sugar are fermented in the rumen, and the rate of fermentation is from slow to fast, respectively. The rapidly available energy for ruminal microorganisms provided by sugars appears to be beneficial in some situations. Overfeeding starch and/or underfeeding NDF can lead to low rumen pH, reduced fiber digestion, and milk fat depression. Adding additional sugar to diets in substitution for starch, even though sugars are fermented more rapidly than starch, does not increase the risk for lower rumen pH and milk fat depression and may increase NDF digestibility (if diets are adequate in rumen degradable protein) and result in higher dry matter (DM) intake. Supplemental sugar shifts the microbial population in the rumen whereby the lactate-consuming bacteria increase, resulting in increased butyrate production. As a result, milk fat concentration often increases with feeding sugars, but milk fat yield may vary depending on how milk yield responds.
Adding liquid sources of sugar to diets may help reduce sorting against large particles in a total mixed ration (TMR). This is especially a potential benefit when the TMR exceeds 50% DM and/or greater than 10% of the particles are on the top screen of the Penn State particle size separator. In addition, sugar from molasses is sometimes used to enhance the palatability of a feed; for example, adding molasses to calf starters.
MOLASSES AS A FEED FOR RUMINANTS
It is important to distinguish between low and high level usage of all types of molasses. At low levels (<20 percent of the diet dry matter), the effect of the soluble carbohydrates in the molasses tends to be complementary rather than competitive and there appears to be little or no depression in the degree to which the basal feed resource is fermented. Beyond a concentration of 20 percent in the diet dry matter, there is increasing competition for substrate by the rumen microorganisms, with the result that the basal diet is used less and less efficiently according to the amount of molasses that is fed.
When molasses accounts for more than 50 percent of the diet, the digestibility of all types of feeds that accompany the molasses is depressed often to the point of only half the value recorded when molasses is not given .These effects are obviously undesirable if the accompanying feed is composed mainly of cell wall carbohydrate: however, if the feed is rich in protein, starch or lipids-which can be digested by gastric enzymes in the small intestine-then depressing the extent to which these nutrients are fermented in the rumen becomes an advantage to the host animal.
Process and products———
Cane sugar is obtained by successive evaporation, cristallization and centrifugation. Both the sugar extraction process and the sugar refining process yield molasses, and each step of these processes output specific types of molasses. Pérez, 1995 has described the different molasses as follows:
• Integral high-test molasses is produced from unclarified sugarcane juice. Because it is concentrated from unclarified sugarcane juice, heavy incrustations and scum deposits lead to frequent mill interruptions and, therefore, to increased factory maintenance costs.
• High-test molasses is basically the same as integral high-test molasses. However, it does not raise as many problems in manufacture as integral high-test molasses does.
• A molasses (first molasses) is an intermediate by-product resulting from first sugar crystal extraction (A sugar), from initial processing at the sugar factory. A molasses contains 80-85% DM. If it has to be stored, it should be inverted in order to prevent crystallization.
• B molasses (second molasses). It has approximately the same DM content as A molasses but contains less sugar and does not spontaneously crystallize.
• C molasses (final molasses, blackstrap molasses, treacle) is the end by-product of the processing in the sugar factory. It still contains considerable amounts of sucrose (approximately 32 to 42%). C molasses does not crystallize and can be found in liquid or dried form as a commercial feed ingredient.
• Syrup-off (liquor-off, jett) is the end by-product from the centrifugation of the final refined masecuite in a raw sugar refinery. Normally, syrup-off is sent to the raw sugar section of the refinery where it is further processed in order to recover more sucrose. Due to its high content of sucrose (90-92% DM), it is an excellent energy source for monogastrics but can be an expensive ingredient.
• Refinery final molasses is the by-product of refined sugar extraction. It has a very similar composition to that of C molasses produced in a raw sugar factory and it is stored in the same tanks.
• In some countries the juice is extracted in a simple animal or mechanically driven press, then boiled in open vats. In this rudimentary process, pan (uncrystallized) sugar is produced and the by-product molasses is called “melote”. It contains only 50% DM.
Molasses is a term applied to a variety of by-product feeds derived from sugar-rich crops.
• it is a byproduct produced during juice / extract prepared from selected plant material.
• It is a concentrated water solution of sugars, hemicelluloses and minerals.
• Four varities of molasses are commonly available viz. cane molasses, beet molasses, citrus molasses and wood molasses.
• Cane molasses is a product of sugar industry and contains 3% protein with 10% ash.
• Beet molasses is a product during production of beet sugar and has higher protein (6%).
• Citrus molasses is bitter in taste with highest protein (14%) and produced when oranges or grapes are processed for juice.
• Wood molasses is a product of paper industry with 2% protein and palatable to cattle.
• Molasses is a good source of energy and an appetiser.
• It reduces dustiness in ration and is very useful as binder in pellet making.
• Molasses can be included upto 15% in cattle ration.
• Feeding Rates
• Molasses is an excellent feed for dairy, beef and sheep. For optimum conversion molasses blends can be included in the diet at up to 10-15% of the total ration dry matter.
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• Molasses and milk protein and quality-———-
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• Generally, it is agreed that high energy feeds can lead to increased milk protein content. Carbohydrate, particularly in the form of rapidly fermentable metabolisable energy (FME), is required to optimise rumen microbial growth and nutrient metabolism. With more high starch containing ingredients included in rations, a greater proportion of the feed energy is coming from starch which, as a rapidly fermentable carbohydrate, can have influence on milk protein. This will be complemented by the rapidly fermentable sugars from cane molasses acting as an energy source A number of trials illustrate this effect.
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• Molasses stimulates microbial growth:
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• Molasses is a rapidly fermentable energy source for rumen micro-organisms. During the 1980’s, dairy cow trials at the Scottish Colleges and Irish research institutes showed that including molasses in the diet increased both microbial efficiency and microbial nitrogen utilization. Indeed, the effect was greater than that of a starch supplement.
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• Nutritive value————
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• The crude protein ranges from 1-2% and TDN from 55-60%. Although low in phosphorus, it is an excellent source of other minerals. Molasses is deficient in thiamin, riboflavin, vitamin A and vitamin D, but it is rich in niacin and pantothenic acid.
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• Inclusion level ———
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• Cane molasses is often included in manufacture of feeds and urea molasses mineral blocks. In ruminant rations molasses is restricted to the level of 10-15% of the ration. Excessive amount of molasses will cause the feed to become messy and unmanageable as well as create digestive disturbance.
Utilization————
Sugarcane molasses has several important roles in livestock feeding, due to the nutritive, appetizing and physical properties of its sugar content. Molasses is difficult to handle because of its viscosity: it is rarely fed directly in its liquid form but instead mixed with other ingredients .
Binding agent, anti-dust agent and palatability enhancer
The main use of cane molasses is as a binding agent in feed mills. Molasses allows the feed granules to stick together during the pelleting process, which produces pellets that are less likely to break down during transportation and passage through feeding equipment. Molasses also reduces dustiness in fine-particled feeds. Due to its sucrose content, it improves the palatability of feeds and can even mask the bitter taste of urea . The amount used in dry feeds is usually small, lower than 15% DM and usually in the 2-5% range .
Silage additive
Molasses is a valuable additive for silage making when ensiling conditions are difficult, or when the forage is a poor quality grass (warm-season grass) or a legume. Molasses provides readily fermentescible energy that promotes lactic acid bacteria development, subsequently reduces pH and improves silage quality. However, molasses may not be helpful when silage is made with maize, sorghum or cool-season grasses since they already contain high amounts of energy, and adding molasses might result in detrimental yeast development . Molasses can be added to grass silage at about 5% .
Urea carrier
Molasses, in either liquid or solid form, is often used as a carrier for urea and other additives . It can be combined with urea, minerals and vitamins to make solids bricks called molasses-urea blocks or multi-nutrient blocks, for instance to supplement low quality diets .
Energy source
Molasses can be used as an energy source for livestock, particularly in situations where grains are unavailable or too expensive . This utilization is common for ruminants, but also occurs in pigs and poultry. Some countries, such as Cuba, have developed feeding systems where molasses has a central part. In ruminants, molasses is fed as a supplement to poor quality roughage, for example during periods of feed scarcity. It can also be mixed with rice bran, oil meals or with non-protein nitrogen (urea) in order to enhance rumen activity .
Other uses
In the tropics, molasses is also used in combination with other ingredients, such as roughages, poultry litter or animal by-products. For example fresh fish, fish offal and snails can be preserved by mixing 50:50 with final molasses, then fed with B molasses to pigs, ducks and geese
• METABOLIC DISEASES ON MOLASSES-FEEDING SYSTEMS
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• Deleterious factors ——-
• When molasses is fed in very large quantities molasses toxicity may develop, which is characterized by neurological defects such as incoordination and blindness. The clinical syndrome is identical to polio encephalomalacia or cerebrocortical necrosis associated with induced thiamin deficiency in ruminants. Molasses toxicity has a complicated etiology and involves an inadequate supply of glucose for the brain, induced thiamin deficiency and rumen stasis. Inadequate glucose status occurs because molasses fermentation produces a high ratio of butyrate to propionate as end products. Butyrate is ketogenic and propionate is glucogenic. An excess of butyrate relative to propionate results in inadequate glucose synthesis and a shortage of glucose for brain metabolism. Molasses toxicity occurs when the roughage component of the diet is inadequate. Low fiber intake results in rumen stasis and the proliferation of slow growing microbes that produce thiaminase destroying thiamin. The combined thiamin glucose deficiency results in brain damage. Provision of adequate roughage is effective in preventing molasses toxicity.
• Three metabolic diseases may occur in cattle and sheep fed diets in which molasses is used as a supplement (as a vehicle for urea) or as the basis of the diet. These are: urea toxicity, molasses toxicity and bloat.
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• Urea toxicity——–
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• With ad libitum feeding of molasses/urea mixtures, urea intakes may reach as high as 300 g/d (e.g. in a 500 kg dairy cow consuming 10 kg/d of the molasses/urea mixture). Even in these cases, there is rarely any risk of urea toxicity since the sugars in molasses and ammonia from urea are quickly used in microbial cell growth. Animals which have never previously consumed urea can be safely permitted free access to mixtures of molasses containing up to 3 percent urea without fear of toxicity. The principle underlying the use of molasses with 8–10 percent urea is that the high urea concentration inhibits consumption of the mixture .Toxicity will only occur if the urea is not uniformly mixed or if the mixture has a high water content which may encourage the animal to “drink” rather than “lick” the mixture.
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• Molasses toxicity————
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• This used to be the most serious problem associated with ad libitum molasses feeding. For example, in the first year following the introduction of the molasses/urea fattening system in Cuba, mortality and emergency slaughter rates in a 10 000 head feedlot increased from 0.1 percent and 0.4 percent (when a forage-based diet was fed) to 1 percent and 3 percent respectively, when the diet was changed to high levels of molasses/urea .
• Cattle suffering from molasses toxicity salivate, stand apart in a “dejected” posture, usually with their head lowered; and frequently are found “leaning” against the fence or feed trough. Invariably, eye-sight is affected and often the animal is blind. When disturbed they have an unsteady and uncoordinated gait .
• The nervous symptoms and blindness, that were a feature of molasses toxicity, indicated damage to the brain
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• Treatment and prevention——-
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• In high-molasses feeding systems, it is usual to restrict the supply of forage (either to stimulate molasses intake or because of the greater cost of forage compared with molasses). Inadequacies in the forage supply, either in quantity or “quality”, appear to be the main causative factors of molasses toxicity. Thus, the incidence of molasses toxicity was less when wheat or barley straw, rather than sorghum forage or maize silage, were used as the forage sources in molasses-based feedlots .Furthermore, there have been no reports of toxicity when high protein forages (e.g. leucaena, and cassava and sweet potato leaves) have been used. Equally, the feeding of palatable forage with a high protein content appears to be the best cure for affected animals. The recent developments in the molasses feeding system have emphasized the technical and economic advantages of giving high protein forages, especially from leguminous trees like leucaena, gliricidia and erythrina, as a combined source of both “roughage” and “bypass” protein .Such procedures are also likely to offer the most cost-effective solution for molasses toxicity.
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• Bloat————-
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• Bloat, which is the retention in the rumen of gas, either free or entrapped in foam, occurs in almost all feeding systems. It is more frequent in the diet of other carbohydrate ;
Compiled & Shared by- Team, LITD (Livestock Institute of Training & Development)
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Reference-On Request.
