The DDR system of feed evaluation. Indices of feed value and feed requirement for feeding and feed planning, with a guide to their use

Beyer, M.; Chudy, A.; Hoffmann, B.; Hoffmann, L.; Jentsch, W.; Laube, W.; Nehring, K.; Schiemann, R.

Das DDR Futterbewertungssystem Kennzahlen des Futterwertes und Futterbedarfs fur Futterung und Futterplanung mit einer Anleitung zu ihrem Gebrauch: 255

1971


Accession: 000216592

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Abstract
The Preface to this publication says: "The contents .. will profoundly influence the work of many and will naturally give indications for improvement to many professionally concerned with its details". It is in essence no more than an extension and modification of the Kellner system of expressing feed value in terms of proximate principles, digestible nutrients and energy value as Starch Equivalent. Section 1 defines the aims: to improve knowledge of the composition of feeds, the planning of rations and their relation to the economics of production. Section 2 defines the units used, feed unit (EF) which has superseded the g-unit of starch equivalent, which was synonymous with 1 kcal net energy for fattening bullocks; energy concentration (EK), digestibility of energy (VE), digestible crude protein (vRP) and the protein:energy ratio (PEQ). The EF unit is not a simple replacement of SE; a species difference has to be allowed for. The EFr (for cattle) is 2.5 kcal net energy for fattening cattle and 1 EFs and 1 EFh are each 3.5 kcal net energy for fattening pigs and poultry. A correction is then applied for type of feed. The tables that follow translate the primary energy values as measured experimentally into these complicated feed units, those for cattle to be used for all ruminants and horses, those for pigs to be used also for rabbits and the poultry units to serve all birds. Energy requirements are translated into kg dry matter (DM) of feeds by the energy concentration ratio EFr/kg DM. Here another correction is required. If the digestibility of the energy of a ration is less than 67% the calculated EFr of the ration is reduced by 1 and then by 2 and 3% as digestibility falls to 50%. Obviously for accurate assessment of energy value DM must be measured and for silage, since volatile substances are lost in drying, another correction is required. Finally, when the EFr, EFs and EFh values are computed from the results of calorimetric experiments, with different coefficients of digestibility of the proximate components for each species, again correction is required for pigs and poultry in respect of cane sugar, milk protein and milk fat, and fodders and fodder silages. There follows an exposition of the use of the system which covers 11 pages with several illustrative small tables on each. Section 3 starts with 16 pages of explanation of ration planning in terms of energy and protein requirements for a year for different classes of stock; yields of fodder plants and concentrates in terms of energy, digestible crude protein and DM; and then with the balance of requirements and supplies. Section 4 has 12 pages of explanatory matter about classification of feeds, stage of development of plants, a list of feeds with table and page references to the main tables of composition. The tables of composition occupy 42 double pages and include, in addition to the components and ratios already specified, lysine, methionine and cystine, all in 3 parts for cattle, pigs and poultry separately. The last 2 pages, for mixed feeds, include also Ca and P, vitamins, urea, antibiotics, antioxidants and coccidiostats. Pages 154-165 show requirements: 166-175 condense the main items of composition for use in planning production; 176-251 similarly condense rules for requirements of the several classes of stock, and the last pages, 252-255, describe the coding system for stocks and feeds which provides the first column in the main tables. It is difficult to imagine how this book is to be of immediate help to those whose practical tasks are to produce crops and feed stock. It suggests college instructors and students, not practical workers. And in spite of all the elaboration of classification and all the applied corrections, there are so many sources of error which are ignored, differences of breed and strain, regional differences, differences due to manurial treatments, it seems doubtful whether it will be much more useful than the old tables of proximate constituents, digested nutrients and SE. Nor is it a handbook for ready reference; it measures 30 X 21 cm. Still, it is a competent presentation of a great deal of information. It is well produced and printed and will no doubt be a useful reference manual for teachers and students. I. Leitch.