What about these method?

Determination of energy value:

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.

Good

http://shodhganga.inflibnet.ac.in/bitstream/10603/6812/11/11_appendix.pdf

http://www.ansc.purdue.edu/swineclass/PDF/Proximate%20Analysis_Blank.pdf

Dear colleague

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,

Redimio

You can calculate the the gross energy of the feed based on its proximate composition. You can use Halver (1976) formula to calculate gross energy content of the feed

GE=4xcrude protein +9xcrude lipid +4xCarbohydrate

HI,

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

Lipids - 9 calories/g of lipid.

Hope it helped.

Thank you for the helpful responses. What units are used for the proximate variables? (protein, Lipids and carbohydrate)

You probably would have calculated proximate composition of the feed as 'x' g/ Kg of feed.

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!

GE =9*fat +4.15 *carbohydrate( soluble carbohydrate + insoluble carbohydrate)+ 5.65*protein

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

We use the following formulas:

- Roughage (except maize): GE [MJ/kg DM] = 0.0188 OM [g/kg DM] + 0.0078 * CP [g/kg DM]

- Maize whole plant: GE [MJ/kg DM] = 0.0196 OM [g/kg DM]

- Concentrate ingredients: GE [MJ/kg DM] = 0.0242*CP [g/kg DM] + 0.0366*EE [g/kg DM] + 0.02 9*crude fibre [g/kg DM] + 0.017*NFE [g/kg DM] - 0.00063*lactose [g/kg DM]

Comment: substraction for lactose only in those ingredients that contain more than 80 g of lactose per kg of DM.

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.

http://www.evapig.com/IMG/pdf/EvaPigManualEquations-3.pdf.

Follow this link maybe helpful

Article Methods of prediction of the digestible energy content of do...

regards

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.

What about these method?

Determination of energy value:

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.

Dear Chisomo Mussa, you can use this equation

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,

Good luck

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...

Thank you very much