Metabolizable energy

Presumes a metabolizable energy density of 14.64 kj/g of dry matter. Ratings greater than 16.74 kj/g should be corrected for energy density. 

Presumes a metabolizable energy density of 16.74 kJ/g of dry matter based on the modified Atwater values of 14.64, 35.56, and 14.64 kJ/g for protein, fat, and carbohydrate (nitrogen-free extract, NEE), respectively. Rations greater than 18.83 kJ/g should be corrected for energy density rations less than 16.74 kJ/g should not be corrected for energy. To convert kj to kcal, divide by 4.184. 

Menke KH, Raab L, Salewski A, Steingass H, Fritz D, Schneider W. The estimation of the digestibility and metabolizable energy content of ruminant feeding stuffs from the gas production when they are incubated with rumen liquor. Journal of Agricultural Science. 1979 93 217-222. 

Wiseman, J. (1984) Assessment of the digestibility and metabolizable energy of fats for non-ruminants. In Wiseman, J. (ed.) Fats in Animal Nutrition. Butterworths, London, pp. 227-297. 

Batal, A.B. and Dale, N.M. (2006) True metabolizable energy and amino acid digestibility of distillers dried grains with solubles. Journal of Applied Poultry Research 15,89-93. 

Cheva-Isarakul, B., Tangtaweewipat, S., Sangsrijun, P. and Yamauchi, K. (2003) Chemical composition and metabolizable energy of mustard meal. Journal of Poultry Science 40, 221-225. 

Choct, M., Hughes, R., Trimble, R.P., Angkanapom, K. and Annison, G. (1995) Non-starch polysaccharide-degrading enzymes increase the performance of broiler chickens fed wheat of low apparent metabolizable energy. Journal of Nutrition 125, 485-492. 

Hainan, E.T. (1944) Digestibility trials with poultry. II. The digestibility and metabolizable energy of raw and cooked potatoes, potato flakes, dried potato slices and dried potato shreds. Journal of Agricultural Science 34,139-154. 

Woodworth, J.C., Tokach, M.D., Goodband, R.D., Nelsen, J.L., O Quinn, P.R., Knabe, D.A. and Said, N.W. (2001) Apparent ileal digestibility of amino acids and the digestible and metabolizable energy content of dry extruded-expelled soybean meal and its effect on growth performance of pigs. Journal of Animal Science 79, 1280-1287. 

Producers need to be aware of these effects, possibly adjusting the level of metabolizable energy (ME) and nutrients in the diet when feed intake is lower than expected, and ensuring an adequate supply of drinking water (preferably cooled) in close proximity to the birds during periods of high ambient temperature. 

Some soybean extraction plants also degum their oil before shipping to centralized refineries. There is not sufficient market to make it profitable to recover all of the soybean phosphatides and market them as soy lecithin. The gums are added back to the meal in the toaster to evaporate the water. The gums contribute to the metabolizable energy content of the meal and the soybean crusher can get meal prices for crude phosphatides. 

Poultry. Lecithin has nutritional application in poultry feeds. The caloric value of lecithin (8900 kcal/kg) for broilers was reported to be greater than tallow (5000-7000 kcal/kg) or soybean oil (8800 kcal/kg) (332). This research was complementary to earlier observations that fat utilization and metabolizable energy value were improved when lecithin was also included in chick diets (333, 334). Phospholipids can increase pigment absorption contributing to egg yolk pigmentation (335). Nutrition also plays a key role in the value of meat. Brazilian research found that lecithin in the diets of broilers improved the sensory scores for breast meat (336). 

Net energy (NE) is metabolizable energy minus the energy lost to the heat of increment. NE may include the energy used for maintenance only (NE ) or for maintenance and production (NE Because NE is used at different levels of efficiency for maintenance or for production, there is no absolute NE value for each feedstuff. Productive energy, once a popular measure of the energy available to poultry from feedstuffs and an estimate of NE is seldom used (16). 

MEn, apparent metabolizable energy corrected for nitrogen retention TME, true metabolizable energy using the rooster unless otherwise stated, and level(s) of fat used in the test diet. Some ME values are not corrected for nitrogen retention, particularly those before 1970. 

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