HORSE BEAN (Vicia faba L.)

Importance and grain composition:

Horse bean (Vicia faba var. equina) is grown for feeding purposes. It is used mainly as a compound feed component and may also serve for green fodder production, often in legume-cereal mixtures for GPS silages. Fava bean (Vicia faba var. major) also serves as food. Either dry of green seeds or pods are used.

Horse bean contains 26-29 % crude protein with relatively high lysine content, therefore it is a good source of protein for compound feed. Nitrogen-free extract content is about 50%, crude fibre 4-7%, fat about 1.5% and minerals about 2.7%.

Horse bean also contains some antinutirtional substances. These include tannins, found mainly in varieties with coloured blossoms, at levels up to 10%. In white blooming varieties their content is low or zero. Other antinutritional substances are glycosides vicine and convicine. These glycosides can be absorbed into blood where they are broken at presence of oxygen and free radicals are formed. If free radicals are not bound, they can damage cells. In the case of red blood cells such a damage may lead to hemolytic anemia. In humans a condition called “favism” has been described induced by fava bean consumption that can be fatal. It is a hemolytic anemia in people with  hereditary deficiency of glucose-6-phosphate dehydrogenase in erythrocytes. In layers, vicine and convicine cause a decrease in egg size and at higher doses also an egg production drop and decrease in egg yolk firmness, or presence of blood in yolk. Consumption of higher amounts of horse bean causes lower utilization of iron and zinc. Therefore when horse bean is included in the diet, levels of both the microelements must be monitored. Heat treatment improves dietetic properties.

 Cultivation requirements:

Horse bean is a plant with long vegetation period, therefore it must be sown early in the spring. It requires heavier loamy to loamy-sand soils, well supplied with nutrients. Soil should not be compacted because this may lead to development of root diseases. Horse bean has a high requirement for moisture, particularly in the period of blooming and seed formation. Horse bean is a good previous crop. Usually it is placed between two cereals. It can also be used as a cover crop for perennial fodder crops, caraway or poppy seed. It is not recommended to be grown in one field at shorter intervals than 4 years.