Sugar Syrup For Poultry Industry

Feeding of poultry has become more innovative as the conversion of feed to poultry production is more efficient than ruminant. Unlike dairy, poultry products like meat and egg are energy dependant on synthesis as the major energy component is utilized for oxidative energy. It is assumed that out of 3200 kcals ME 1500 Kcals is used for the body maintenance and 800 kcals for products synthesis. The incorporation of carbohydrates into chicken meat or egg is insignificant as the composition is with the nutrients like water, protein, fat and mineral. Every year the marketing age of broilers decreases by an average of 0.75 days for the same performance. This trend is likely to continue in the same direction for the coming years. Nutrition plays a vital role in enabling this improvement. As the feed cost represents an expensive input (~70-80% of broiler production cost), the poultry producer should be aware of the dynamics of the feed in its influence on final product quantity and quality.

Formulating feed ideally requires in-depth knowledge of several parameters such as the energy level to be maintained in the diet, balancing the amino acid profile and electrolytes of feed, etc., which, otherwise, if not properly monitored, could negatively influence the performance and profitability of the business. Further, in light of environmental challenges and disease outbreaks, it is even more challenging to extract the total genetic capability of the birds.

Dietary Energy

The most vital nutrient in the poultry ration is considered ‘dietary energy’ even though energy itself is not converted into meat or egg in poultry except liponeogenesis. Moreover; it is used as fuel for the synthesis of meat or egg. Therefore 60-65 % of the metabolisible energy in the poultry ration is imputed to carbohydrate. Environmental temperature and the energy content of the feed are key determinants for the feed intake of the bird. Other nutrients are normally adjusted based on the feed intake of the bird. There exists a relationship between energy and digestible amino acids, which if maintained, will enable adjustment of crude protein levels in the diet, thereby reducing the feed cost without compromising performance. Optimum live performance, maximum protein retention and reduced carcass fat content can only be obtained if a proper ratio between energy and digestible amino acids is maintained. However these ratios vary between different growing periods, i.e. Starter, Grower and Finisher.

The requirement of energy for poultry is referred as metabolisible energy (ME). 4000 kcals of gross energy from 1 kg carbohydrates will be 3200 kcals digestible energy after loosing 800 kcals in faces. Another 300 kcals is lost through urine to make 2900 kcals as the metabolisible energy (ME). Furthermore 600 kcals lost as heat increment to yield 2300 kcals as net energy (NE). It is assumed that 1500 kcals is the requirement for maintenance and 800 kcals for meat and egg production. (See NRC ,1994). It could be inferred that poultry utilizes 20% dietary energy for product synthesis while 40% is used for its body maintenance.

Table 1. Nutrients composition of poultry products.

Nutrient	Broiler Meat	Egg
Water	65.7	66
Protein	18.4	13
Fat	12.2	10
Minerals	3.7	11

Dietary energy level is the main factor influencing feed intake, as birds will, under normal circumstances, eat to satisfy their energy needs. Therefore the dietary nutrients, protein vitamins and minerals should vary in relation to the dietary energy content of the diet, if they are not to become deficient, with low feed intakes, or over consumed, with low energy diets. While there are a number of factors, such as level of protein, balance of essential amino acids and perhaps level of some of the other dietary nutrient, that can influence the cost of a diet, the level of dietary energy is usually the main factor influencing diet cost. Hence, by and large, the higher the level of energy the higher the diet cost and usually the lower is the feed consumption in relation to gain.

The energy content of a diet is usually given as so many calories per kilogram of diet. Thus diets are said to contain, for example, 2800 or 3200 kcal per kilogram. Energy is the fuel that keeps the many different body functions operating, every minute of the day. It is a vital feed component, a costly feed component and the most wasted of the feed components. Hence, everything should be done to enhance the utilization of dietary energy for productive body functions, as improvements readily show up in increased monetary returns which are readily apparent by improved feed:gain or egg mass ratios.

The physiological mechanisms by which poultry respond to different dietary energy concentrations are not known, although several possible mechanisms have been proposed (National Research Council, 1987). Although poultry generally adjust feed consumption to achieve a minimum energy intake from diets containing different energy levels, these adjustments are not always precise. Morris (1968) summarized data from 34 experiments and found that laying hens over consumed energy when fed high-energy diets and the degree of over consumption was greatest for strains with characteristically high-energy intakes. Data from a large number of broiler chicken experiments also showed that changes in feed intake were not inversely proportional to changes in dietary energy level, especially when broilers were fed moderate- to high-energy diets (Fisher and Wilson, 1974). More recent studies also illustrated that growing broilers and turkeys consume more energy when fed high-energy diets than those fed low- to moderate-energy diets (Sell et al., 1981; Owings and Sell, 1982; Sell and Owings, 1984; Brue and Latshaw, 1985; Potter and McCarthy, 1985).

Fat in Poultry Diet

In order to increase the dietary energy the addition of oil and fat is recently practiced. Several workers have suggested the use of fatty acids in the diet for energy. Renner and Hill (1961), Young and Garrett (1963), Lewis and Payne (1966), Hakansson (1974), Leeson and Summers (1976a), Fuller and Dale (1982), Ketels et al. (1987), Ketels and DeGroote (1988), and many others. It is well known that utilization of saturated fatty acids is improved by the presence of unsaturated fatty acids in the fat blend (Young and Garrett, 1963; Young, 1965; Lewis and Payne, 1966; Garrett and Young, 1975; Leeson and Summers, 1976a). The nature of the fat in the basal diet has a significant effect on the utilization of supplemental fats (Sell et al., 1976; Sibbald and Kramer, 1978; Fuller and Dale, 1982). These interactions between the supplemental fat and the basal dietary fat are especially noticeable at low inclusion levels of supplemental fat (Wiseman et al., 1986; Ketels et al., 1987).

Oxidation of fatty acids yields enormous amounts of energy on a molar basis; however, the carbons of the fatty acids cannot be utilized for net synthesis of glucose. The two carbon unit of acetyl-CoA derived from b-oxidation of fatty acids can be incorporated into the TCA cycle, however, during the TCA cycle two carbons are lost as CO2. Thus, explaining why fatty acids do not undergo net conversion to carbohydrate. The glycerol backbone of lipids can be used for gluconeogenesis. In fact adipocytes require a basal level of glycolysis in order to provide them with DHAP as an intermediate in the synthesis of triacyglycerols.

Feeding fats provide a concentrated source of energy, but there are other reasons for using fat such as improving the physical characteristics of the feed.

     • Fat decreases dustiness (feed loss is reduced by effective dust control).
     • Fat improves palatability of feed.
     • Fat increases lubrication value of feed.
     • Fat reduces particle separation (helps maintain uniform mixture of the ration).
     • Contributes an essential fatty acid, linoleic acid.

The dietary fat in poultry ration is found to alter the fatty acids profile in egg. (See table 2). The fatty acid composition of yolk lipids was affected (P>0.05) by the experimental diets. The major effects of the diets were observed in fatty acids C16:0, C18:0, C18:1n9, C18:2n6, C20:4n6, C20:5n3 and C22:6n3. The addition of oils to the diets fed to hens allowed the production of eggs with higher n3/n6 and PUFA/SFA fatty acid ratios than the eggs from control hens. It was concluded that the amounts of saturated and unsaturated fatty acids in egg yolk could be altered by dietary manipulation. (see M. C. Milinsk, A. E. Murakami, S. T. M. Gomes, M. Matsushita and N. E. de Souza).

Table 2. Effect of dietary fat on egg lipid profile.

Particulars	SFA	MUFA	n-3	n-6
Control	33.04	50.07	1.97	14.40
Canola oil	30.03	51.56	3.08	14.90
Sunflower	30.38	41.55	1.64	25.80
Soybean	31.69	45.45	2.55	19.79

        SFA saturated fatty acid
        MUFA mono unsaturated fatty acid
          n-6 linoleic acid
          n-3 linolenic acid

In all animals, obesity results from an energy imbalance that occurs when more food energy (calories) is consumed than the body actually needs. The excess energy is stored mostly as fat. Over the years, poultry breeders have bred chickens that grow faster and produce more meat in response to a growing worldwide consumer demand. But modern broiler/breeder chickens don’t adequately balance their feed consumption to match their energy requirements. When these birds are given unrestricted access to feed, they will overeat and become obese.

An important biochemical pathway was discovered in animals that maintains energy balance in the body. A key component of the pathway is an enzyme called “AMP-activated protein kinase” (AMPK), which helps to regulate both energy use by individual cells and food intake by the animal. This pathway is currently being studied in chickens and turkeys.

Animal scientists Monika Proszkowiec-Weglarz and Mark Richards in the ARS Growth Biology Laboratory at Beltsville, Maryland, along with research leader John McMurtry and Penn State University collaborator Ramesh Ramachandran, recently identified and sequenced the genes responsible for the AMPK pathway in birds and showed that they function in different tissues throughout the body of the broiler chicken.

According to Proszkowiec-Weglarz, AMPK plays a central role in sensing cellular energy levels. It begins a series of events that affect food intake and metabolism of fat, carbohydrate, and protein. “AMPK is really a molecular fuel gauge and a master metabolic regulator in cells,” she says. “It responds to fluctuations in the levels of cellular energy and of specific extracellular nutrients and hormones.”

Cells obtain energy from conversion of adenosine triphosphate (ATP) to adenosine monophosphate (AMP). “AMPK senses the ratio of AMP to ATP and works to raise the level of ATP within cells” says Proszkowiec-Weglarz. “Our goal is to learn how the AMPK pathway functions in birds to achieve energy balance, so growers can efficiently produce chickens of optimal weight while minimizing excess fat.” (US Department of Agriculture ,2008.)

The non-proliferating chicken liver cell culture system described yields cell monolayers with morphological and lipogenic properties characteristic of the physiological-nutritional state of donor animals. Synthesis and secretion of fatty acid, cholesterol, and very low density lipoprotein (VLDL) occur at in vivo rates and respond to hormones and agents which affect these processes in vivo. Cells derived from fed chickens maintain high rates of synthesis of fatty acid and cholesterol for several days if insulin is present in the medium. High rates of fatty acid synthesis are correlated with the appearance of membrane-enclosed triglyceride-rich vesicles in the cytoplasm; deletion of insulin causes a decrease (T1/2 = 22 h) in fatty acid synthetic activity. Addition of glucagon or cyclic AMP (cAMP) causes an immediate cessation of fatty acid synthesis and blocks the appearance of the triglyceride-rich vesicles. Fatty acid synthesis in liver cells prepared from fasted chickens is less than 5% that of cells from fed animals. After 2-3 days in culture with serum-free medium containing insulin +/- triiodothyronine, fatty acid synthesis is restored to normal; glucagon or dibutyryl cAMP blocks this recovery. Liver cells derived from estradiol-treated chickens synthesize and secrete VLDL for at least 48 h in culture. (DM Tarlow, PA Watkins, RE Reed, RS Miller, EE Zwergel and MD Lane ).

The above phenomenon suggests that feeding of sugar syrup which may increase the blood glucose level may stimulate the release of insulin into the blood which may decrease the production of glucogon. It may enhance the lipogenesis in liver. It may also reduce the oxidation of dietary fat into acetyl CoA for the release of ATP. Eventually this may increase the growth rate and also egg production.

The inclusion of dietary fat in poultry has become quite normal with the incorporation of fat coater in feed mills. The advantage of higher ME addition to the ration with low fibre and less aflatoxin has encouraged the fat addition. The possible lipid profile changes in egg cautions the poultry nutritionists in fat addition. More over the high cost of fat increases the feed cost.

Sugar Syrup – A New feed

There has been a recent approach to feed technology and animal nutrition to develop sugar syrup an intermediary product of sugar refining to develop as energy feed for poultry. In the Middle East where the cost of grains is increasing beyond control the development of sugar syrup has been considered a recourse to poultry feed.

Development of sugar syrup

Molasses is the last residual product comes out from refinery. It is highly viscous syrup with 48% sugar and more than 20% ash. Because of the several boiling (say 13) the sugar gets caramelized, bound to the organic substances like glue and polysaccharides which depresses the digestibility of molasses. As a matter of fact the sugar companies were not interested to keep up the quality of molasses since its main use was for alcohol production. The use of molasses as an energy feed was not considered in animal feeds. Often it is used as a binder, dust reducer and sweetener with a low inclusion rate. In that matter, the demand for molasses was low in animal ration.

Al Khaleej Sugar Co development team examined the possibilities of improving the quality of molasses to make it a suitable feed ingredient. The decision was taken by the Chairman Mr. Jamal Al Ghurair and the process parameters were defined. This resulted in the production of a high quality molasses with 77% sugar which named as AKS Sugar Syrup.

There was research data even though scarce on feeding sugar to animals. The NRC had published a ration for poultry with 15% pure sucrose in 1994 publication. Several other research papers described the advantage of sugar feeding. The concept of better metabolisibility of sugar than starch supported the development work in AKS.

Sugar Digestion in Poultry

The saliva and crop of the chicken contain some a-amylase , but little starch digestion has been demonstrated in the crop and proventriculus gizzard. The digestion of most carbohydrates (polysaccharides) into monosaccharide and their subsequent absorption take place in the small intestine. Alpha-amylase is secreted from the pancreas into the duodenum and this hydrolyses the 1,4’ α-linkages on both sides of the 1,6’ branching points in starch, producing mainly maltose and some branched oligosaccharides (isomaltose). The enzyme maltase, also called a-glucosidase, splits maltose while oligo- 1,6’-glucosidase (isomaltase) produced by the intestinal mucosa hydrolyses the branched oligosaccharides into glucose. The brush border membrane of the jejunum contains other disaccharidases that complete the digestion of complex dietary polysaccharides into monosaccharides. Sugars have been accepted as better energy donor than starch in the animal system. Chamberlain et al (1993) concluded that sugars, particularly sucrose are certainly superior to starch. Mahagna and Nir (1996) indicate greatest maltase activity in the jejunum, followed by the ileum while the lowest value was seen in the duodenum. It is seen that the metabolisability of sucrose is significantly higher than starch.

Table 3. Energy availability from starch & sugar.

Particulars	GE (kcal/kg)	ME (kcal/kg)	Metabolizability (%)
Starch	3760	2918 - 3396	78 - 90
Sucrose	3960	3900	98

The digestion of carbohydrates in poultry is summarized below:

Table 4. Carbohydrate Digestion in Poultry (S. Leeson and A.K. Zubair)

Sugar Syrup – A High Energy Feed For Poultry Industry - Image 2

Sugar Syrup – A High Energy Feed For Poultry Industry - Image 2

The energy content in sugar syrup could be compared with that of Corn (see table 5.) The net energy available from Corn is less owing to various nutrient loss during digestion and metabolism. Further more there is a loss owing to heat increment. Since the sugar syrup has no indigestible matter the total sugar is converted into monosaccharides and is available to birds with out any heat increment.

Table 5. Energy partition in Corn and Sugar syrup

Moities	Corn	Sugar Syrup
Protein (G)	360	160
Fat (G)	360	0
Starch (G)	2960	0
Sugar (G)	0	4010
G. Energy Kcal	3680	4010
ME Kcal	3200	4010
NE Kcal	2600	3900

The feeding of grain has an effect on the viscosity of the gut. Most of the studies have also reported reduction in digesta viscosity associated with improved performance.

Sugar syrup is a rich energy feed that could be well incorporated in feeds. Since its energy value is more than Corn it could be an economical substitute in poultry feeds. This could bring a sea change in poultry feed formulations because sugar syrup contains no indigestible material and there fore it is an instant energy feed. It adds the aroma and palatability of the feeds. Since the syrup contributes energy without the addition of lipids the formation of cholesterol in egg and meat could be minimized. Even though sucrose is considered a food additive for man sugar syrup a by product of sugar industry could be used a major feed item for poultry

Table 6. Comparison of analysis for Corn with Sugar Syrup

Particulars	Corn	Sugar Syrup
Dry matter %	89	80
Crude protein %	9.6	4.6
Fibre %	2.5	0
Fat %	4.1	0.2
Ash %	1.5	4
NDF %	14.5	0
ADF %	2.6	0
Starch %	75	0
Sugars %	0	77
Met. Energy MJ/kg	13	15
Calcium %	0.1	0.92
Phosphorus %	0.3	0.2
Magnesium %	0.1	0.17
Potassium %	0.4	0.85
Sodium %	0.1	0.1
Lysine %	0.8	0.02
Glucose + Fructose	0	77
Sucrose %	0	35

Sugar syrup has been used in poultry feed for the following reasons:

     • Increases the palatability of the feed.
     • Improves the dry matter digestibility
     • 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
     • Enhances the lipogenesis in liver
     • Reduces the lipid oxidation
     • Sugar syrup is free of aflatoxin
     • Decreases the viscosity of digesta in gut.

Conclusion

The development of Sugar syrup has opened a new vista in poultry ration as it contributes high energy with less heat increment. The zero content of fibre and no afaltoxin makes it superior to Corn in the ration. Further more its low cost compared to Corn attracts poultry farmers/feed professionals. Its 60 % dietary energy with oil with 30% cost would go a long way in revolutionizing the poultry feed in future.