The metabolizable energy of poultry feeding stuffs in relation to their chemical composition

Abstract

The metabolizable energy values of 17 samples of cereals, cereal by-products and mixed rations have been determined with laying hens. They ranged from 1300 to 3500 kg.-cal. per kg. and, where comparison with the findings of other workers has been possible, agreement has been generally satisfactory. The same samples were subjected to the standard methods of proximate analysis, and also analysed for their content of starch and reducing sugars using a specially modified anthrone method. Statistical analysis of the results showed that the formula-53 + 38 (yo crude protein + 2.25 x yo ether extract + 1.1 x yo starch + yo sugar) gave predicted figures for the metabolizable energy (in kg.-cal./kg.) of the materials tested with a standard deviation of & 190 kg.-cal./kg. from the determined figures. This was a superior prediction to any that could be made with the data from proximate analysis alone, and the method may prove of use when an estimate of the energy value of a material or mixture for feeding to poultry has to be made from results of chemical analyses that can be carried out in a routine laboratory. IntroductionIf two mixed rations are both adequately fortified with protein, minerals and vitamins, the principal factor limiting the productive performance that can be obtained with the same quantities of each are their respective energy contents. For the same performance less is required of the ration with higher energy content.It is of obvious value to have simple routine methods of chemical analysis that can be used to estimate the nutrient content of rations and their component parts. For single specific nutrients, such as the individual minerals and vitamins, this is a straightforward analytical problem. The energy ' value of a feeding stuff is not however a function of content of any single chemical entity. The vaIue of any formula used to estimate the energy content of a feeding stuff from its chemical analysis must therefore depend, in an empirical way, on the correlation of such calculated figures with experimentally determined energy values.There is general agreement that the standard system of proximate analysis does not give figures that can be correlated closely with the energy value of poultry feeding stuffs. This is largely explain,ed by the great differences in the digestibility of the ' nitrogen-free extractives ' (N.F.E.) of different materials.'* a However, in one series of digestibility trials, with more detailed analysis of nine materials, it was found that the portion of the N.F.E. analysed as ' starches + polysaccharides + reducing sugars was in each case over 90% digestible, and their content of these carbohydrates ranged from 4 to 63y0.1 The contribution of digestible nutrients

The effect of replacing soya bean oil with glycerol in diets on performance, egg quality and egg fatty acid composition in laying hens

“…Glycerol used in this experiment contained 15.90 MJ ME/kg. ME levels of glycerol were estimated using Carpenter and Clegg's (1956) equation: ME (kcal/kg) = 53 + 38 [(CP, %) + (2.25 × ether extract, %) + (1.1 × starch, %) + (sugar, %)]. The experimental diets were formulated to be isocaloric and isonitrogenous.…”

Measurement of Bioavailable Energy in Poultry Feedingstuffs: A Review

“…Titus (1958) extended and refined the work of Fraps et al (1940) by deriving a series of 'percentage multipliers' which permit calculation of the AME values of individual f'eedingstuffs. Opstvedt (1973) (Opstvedt 1976 (Janssen and Terpstra 1972;Jannsen et al 1975Jannsen et al , 1976Janssen 1916Janssen , 1919 (Connor et al 1976) and oats (Davidson et al 1978 Carpenter and Clegg (1956), Bolton (1962b) and Sibbald et al (1963) whereas the equations ofTitus (1958) produced reasonably accurate data (Guirguis 1975 Coates et al 1911a). No equation was able to give satisfactory TME values for wheats but the TME values of oats (Sibbald and Prtce l9lla) and barley (Sibbald and Price 1916b) were well predicted by some equations.…”

“…However, according to Erbersdobler and Riedel (1912) Work with mice has shown that intestinal microflora alter cell renewal rates in the ileum (Abrams et al 1963), duodenal crypts (Lesher et al 1964) and small intestine (Khoury et al 1969 Yoshida et al (1965), Yoshida and Morimoto (1966,1970) and Squibb (1971 (1961) found the AME values of oats to increase with bushel weight; this was confirmed by Sibbald and Slinger (1963a), Sibbald and Price (1976a) but not by Salo (1978) whose AME values were calculated from chemical composition. The TME values of oats were related to bulk density (Sibbald and Price 1977a) as were ADE values measured with mice (Christison and Bell 1975 (Hochstetler and Scott 1975 Carpenter and Clegg (1956), Bolton (1962b) and Sibbald et al. (1963).…”

Effects of Dietary Yeast Cell Wall Supplementation on Performance, Carcass Characteristics, Antibody Production and Histopathological Changes in Broilers

“…The samples were ashed in a muffle furnace prior to the analysis of calcium and total phosphorus [11,12] . Metabolizable energy levels of samples were estimated using the Carpenter and Clegg's equation [13] .…”