The metabolizable energy of field beans (Vicia faba L.) for poultry.

Although beans are grown primarily because samples they are richer in protein than the cereal grains, the energy they contribute to mixed diets is also important. An unpublished computer calculation of least-cost formulae for laying hen diets has indicated that if two samples of bean meal were of the same composition, except that one had 300 kcal/lb more metabolizable energy (M. E.) than the other, its worth would be more than £3/ton greater. The actual range of values taken for bean meals in this country is considerably wider than 300 kcal/lb. Bolton (1963) lists a value of 830 kcal/lb, whilst Bolton (1967) lists 1400 kcal/lb. Titus (1955) lists 610 and 640 kcal/lb though specifying that these values refer to navy beans and pinto beans respectively (both being Phaseolus vulgaris ). Bletner, Chalhoub & Geff (1963) were unable to find any published value for ‘horse’ or ‘field’ beans as (i. e. Vicia faba ), the type normally used for animal feeding in Britain.