The energy value of the date fruit varieties was calculated based on their content of crude protein, fat and carbohydrate using formula described by Crisan and Sands (1978) as follows:
Energy value (kcal/100 g)=(2.62 x %protein) + (8.37 x %fat) + (4.2 x % carbohydrate)
Crisan E.V. and Sands A., (1978). Nutritional Value. Academic Press, New York, pp. 137–168.
usually it is most important look to digestible or metabolic energy estimation, using ecuations that involved proximate analysis outputs. Gross energy, as far I know, is determined with calorimeter, and I do not know a formula to do estimation of gross energy from proximate analysis. best regards,
You may use Bomb calorimeter to estimate the gross energy in feed. However, if you already have proximate composition then it becomes much more easier. In any feed there are 3 components that are metabolized to generate energy and they are lipids, carbohydrate, and protein. As Amit Ranjan has answered, you simply multiply the calorific values of each of these energetic components to obtain gross energy. The calorific values are:
Protein and carbohydrate - 4 calories/g of nutrient
Gross energy can be determined by direct calorimetry (burning in a calorimetric bomb 1 g). There is a calculation formula in which the raw nutritive substances are multiplied by different calorific coefficients depending on the type of feed. However, this determination is not very important because most feeds have this value close to 4400 kcal.
It is possible if you were working on this topic with mathematical and instrumentation competence. Simply measure the GE with calorimetry and also generate the proximate values. You may then set up multi-regression equations whereby the GE and the proximate values are correlated. It will be a nice contribution. Such contribution is good for individual feedstuffs for better predictability. But of course know that this is only for estimation purposes as the real values may always differ as the chemical compositions differ within and between ingredients. Also you could determine GE and also measure the digestibility of energy, or reasonably assume its digestibility. With a knowledge of the DE, you may always mathematically predict GE!
I agree the better caloric values are mention by Ramadn Allam-Sayed Abdelrasoul. But, the more accurate method is calorimetric pump. In proximate analysis,is :
GE /kg = CPg * 5,65 + (CF g + NFEg) * 4,5 + EE g * 9
Compute the Metabolizeable energy using the Pauzenga equation and divide the value by the factor for specific animal. For example 0.82 for poultry. For pigs consult the consult the following manual.
According to ARC (1977), there are two main regression formulae used in poultry:
1. ME (Kcal/kg) = 4.31 x g.dCP + 9.28 x g.dEE + 4.14 x g.dNFE
2. ME (Kcal/kg) = 3.82 x g.CP + 7.85 x g.EE + 4.1 x g. starch + 3.6 x g. sugar Where digestibility coefficient (d) estimates are 90% for CP, EE (90%), CF (0%), and NFE (80%). The calculation of metabolisable energy assumes that feedstuffs do not have anti-nutritional factors. In this case, digestibility coefficients of feedstuffs are numerically the same (Moughan et al., 2000).
To calculate the Digestible energy, values of digestiblity coefficients of CF and associated constants can be included in the formula depending on the animal species.
Energy lost in faeces is about 20% (DE = 0.8GE), and 5% lost in urine (ME = 0.95DE)(Pond et al., 1995). If DE is known from proximate analysis, GE can be calculated.
The energy value of the date fruit varieties was calculated based on their content of crude protein, fat and carbohydrate using formula described by Crisan and Sands (1978) as follows:
Energy value (kcal/100 g)=(2.62 x %protein) + (8.37 x %fat) + (4.2 x % carbohydrate)
Crisan E.V. and Sands A., (1978). Nutritional Value. Academic Press, New York, pp. 137–168.
GE (MJ/kgDM) = 0.0226 CP + 0.0407 EE + 0.0192 CF + 0.0177 NFE
CP as g/Kg it is not % and the same for CF and NFE
MAFF (1975).Ministry of Agriculture, Fisheries and Food. Energy allowance and feeding system for ruminants. Technical bulletin 33, Ministry of Agriculture, Fisheries and Food, HMSO, London,
Is there informations about energy value for calves fed milk replacer? is there equation on energy contain of ingredients used to formulate milk replacer as Palm oil, gluten protein...
The gross energy (GE) in a food is defined as the total chemical energy measured from complete combustion of the food in a bomb calorimeter. Digestible energy (DE) and metabolizable energy (ME) are the more typical terms used in canine and feline nutrition. Digestible energy refers to GE minus energy lost in feces.
Proximate analysis of a fuel provides the percentage of the material that burns in a gaseous state (volatile matter), in the solid state (fixed carbon), and the percentage of inorganic waste material (ash), and is therefore of fundamental importance for biomass energy use.
Process can be extracted towards kijeldahal procedure and ether extraction.
Formula for GE calculations,
1. GE(Old GE formula) = 4,143 + 56 × EE + 15 × CP – 44 × Ash
Crude protein (CP), ether extract (EE), crude fiber, ash, This equation still is valid for general fuel. Ingested energy= Gross energy
2. GE for animal feed, GE = 5.7× g protein +9.4× g fat +4.1× (g NFE + g fiber), The calculation for nitrogen free extract is: % NFE = 100 % – (% EE + % CP + % Ash + % CF).
CF= Crude Fiber, NFE- Nitrogen Free Energy
3. DE(digestive energy) = GE × percentage energy digestibility/100 and, subsequent calculation of ME(Metabolizable Energy) in dogs as ME = DE – (1.04× g protein) and in cats as ME = DE – (0.77× g protein).
4. To calculate gross energy content on a DM (Dry Matter) base, the following formula can be used;
Gross energy(Kj /kg)(DM) = (C x ∆T - QF)/ (Mp x DM of AD)
Were C is the warmth capacity of the calorimeter (J/k); ∆T is the measured temperature rise; QF is the sum of all foreign energies (wire and fibre, (J)); Mp is the weight of the sample (g) and DM of AD is the percentage of DM in the air-dried sample.