Sugar syrup – a dietary energy feed
The most vital nutrient in the poultry ration is considered ‘dietary energy’ even though energy itself is not converted into Glucose in meat or egg except for 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. 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). The most accepted energy feed in poultry ration is cereal grains.
Dietary carbohydrates are important sources of energy for poultry. Cereal grains such as corn, grain sorghum, wheat, and barley contribute most of the carbohydrates to poultry diets. The majority of the carbohydrates of cereal grains occur as starch, which is readily digested by poultry (Moran, 1985a). Therefore; in a poultry ration cereal grains are the most acceptable ingrediants for energy. 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, 1987a). 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).
Feeding fats provide a concentrated source of energy, but to alter the fatty acids profile in egg. (see table 2). The fatty acid composition of yolk lipids was affected by 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).
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 70% 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 metabolisible 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 (poly saccharides) into monosaccharides 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. Sucrose is hydrolyzed by sucrase into glucose and fructose, while lactase converts any lactose into glucose and galactose.
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 No 1. Energy values for starch and sugar.
|Particulars||GE (kcal/kg)||ME (kcal/kg)||Metabolizability (%)|
Sugar Syrup – Poultry
|Total Sugar as Invert||75|
|Metabolizible Energy MJ/kg||18|
In order to prove the efficacy of sugar syrup as good source of dietary energy for poultry a feeding trial was envisaged. The trail was separated for broiler and layer birds. The poultry feeds with varying levels 0,5,10 and 15% of sugar syrup were incorporated into the feed. The formula for different broiler feeds are given below:
Table 2 Different formulations with graded levels of Sugar syrup.
One day old Hubbard commercial broiler chicks of 100 per pen with 3 replicas for one control and three treatments were used. The growth performance was measured at 0, 14, 28 and 35 days and the results are given in table 3
Table No 3. Growth performances of broiler chicks.
|Treatments||Initial||14th day||28th day||35th day|
|5% sugar Syr||46||346||700||1590|
The group with 5% sugar syrup showed better growth than the control group. However; the 10% group showed the least growth rate. The 15% group showed insignificant growth rate to the control group. Therefore, the concept of high dietary energy concentration in sugar syrup and its high ME value is getting acceptable with the trial data. If the ME value that was calculated for the formulations were incorrect the higher inclusion rates of syrup would have depressed growth for want of dietary energy. The blood parameters were also showed the efficacy of sugar syrup with out any deleterious effect on health of birds. The blood parameters are shown as table 4.
Table 4. Blood parameters for broiler chicks fed with Sugar syrup
|Blood parameter||Control||5% Sugar Syr||10% Sugar Syr||15% Sugar Syr|
The slight elevation of blood glucose is the indication of high glucose supply through sugar syrup feeding. All other parameters are with in normal range.
Table 5. Feed intake with Sugar syrup feeds
|Treatments||2nd week||3rd week||5th week|
While examining the feed intake there is no significant difference with in groups. The most important benefit of sugar syrup feeding was the economical advantage. The formula costs could be reduced significantly while sugar syrup inclusion. The graphs prepared show the face very clearly.
A significant observation noticed is the reduction in cholesterol level in blood. The data is given as table 6.
Table 6. Cholesterol & Triglycerides level in blood
|5% Sugar syrup||135||31|
|10% Sugar syrup||128||33|
|15% Sugar syrup||132||8|
|5% Sugar syrup||68||11|
|10% Sugar syrup||72||60|
|15% Sugar syrup||77||17|
The poultry nutritionists were striving to reduce the cholesterol level in chicken meat and egg. The methods that are practiced were intricate and expensive. More over the addition of vegetable oil to enhance the ME value in feed elevated the cholesterol level. The future research into the incorporation of sugar syrup would go a long way in ameliorating the cholesterol problem to a certain extend. The present studies indeed opened the gate way for it.
Fig 1. The formula cost for Broiler Starter feed with different levels of Sugar syrup inclusion.
Fig 2. Broiler Finisher feed with different levels of sugar syrup inclusion.
The economic benefit was due to the substitution of Corn and vegetable fat. The energy value, its unit cost for those feeds are shown below:
Table 6 Cost: Nutrient comparison with energy feeds
|Met. Energy (K Cal/kg)||9000||3300||4000|
|Unit cost/K cal||0.38||0.27||0.20|
The above research trial carried out with a joint collaboration with the UAE University, Al Ain supported the hypothesis of high dietary energy for the Sugar syrup developed at Al Khaleej Sugar Co LLC. The sugar syrup utilization for dairy cows has increased four fold since two years of the development. The evolving of the new feed for poultry industry would go a long way to ameliorating the high feed price for poultry which may support the poultry production. The high price for Corn and vegetable fat will affect the price of poultry products. The zero fibre and no toxin in sugar syrup would be an added advantage for the use of sugar syrup in poultry feed.
PUBLICATION DATE: 15/04/2010
AUTHOR: Dr. P. George K John