Effect of extrusion on the chemical composition of the faba beans and its influence on lactation performance of dairy cows

The objective of the experiment was to study the effect of extrusion process on the nutritive value of faba beans and to determine its effect on lactation performance of dairy cows. The faba beans were extruded in a single screw extruder at a temperature of 135-155 degrees C. Feed samples were analysed for chemical composition, including amino and fatty acid composition (before and after extrusion). To evaluate the effect of field beans on dairy cows' performance and milk composition, a feeding trial using extruded and non-extruded faba beans in the diets was conducted. The extrusion process had a minor effect on the chemical composition of the faba beans; the crude protein and crude fat contents increased, while the neutral detergent fibre fraction and dry matter decreased. Moreover, no significant effect on the n-6:n-3 ratio of fatty acids and the atherogenic and thrombogenic indices in beans was found. The replacement of un-extruded beans with extruded beans in dairy cow diets had no effect on feed intake or milk yield. Administration of extruded faba beans with concentrate mixture had no effect on other milk traits or efficiency parameters either. These findings indicate that extrusion improves the composition of beans, but the effect on lactation performance of dairy cow is marginal.