Toasted faba beans as economical replacement of soybean expeller meal in organic dairy rations

Triticale as a forage crop is a common choice in the crop rotation of organic dairy farmers in Belgium. The last decade triticale is often grown in combination with faba beans. This not only increases dry matter yield but certainly the crude protein yield per ha and reduces the need for external protein-rich inputs. However, the protein of faba beans is easilydegraded in the rumen. In combination with the protein from gras/clover the amount of easily degradable protein in the rumen is often too high with protein losses as a result. To achieve high milk production, additional protein rich concentrates are still necessary usually in the form of soybean expeller meal. In order to reduce the rumen degradable protein three organic dairy farmers toasted their home grown mixture of faba beans and triticale using a mobile toaster. The rumen degradability of the toasted grains was analysed using the in sacco digestibility method and compared with the untoasted material. The percentage of rumen undegradable crude protein increased from 27 to 45% in the faba beans. Hereby the DVE value (DarmVerteerbaar Eiwit = protein digestible in the intestine) increased from 134 to 184 g/kg dry matter (DVE soybean expeller meal = 261 g/kg dry matter). The degradability in the rumen of the starch of triticale also reduced, which increases the possibility to feed higher amounts of toasted triticale without the risk of rumen acidosis. Four ‘on farm’ feeding trials were conducted. The animal performances during a period with feeding toasted faba beans were compared with a period with less beans and a higher amount of soybean expeller meal. Replacing soybean products with toasted faba beans did not change milk production and milk composition but reduced the feeding cost, resulting in a higher income for the farmers. It was concluded that toasting faba beans is apro fitable procedure that can increase the proportion of regional protein sources in organic dairy rations.

ISBN:978-90-8686-366-2