Effect of Raw and Extruded Propionic Acid-Treated Field Beans on Energy and Crude Protein Digestibility (In-Vitro and In-Vivo), Growth and Carcass Quality in Grow-Finisher Pigs

SIMPLE SUMMARY: European pig meat production is highly dependent on imported soybean meal (SBM). The area of field beans produced in the EU has increased greatly in recent years. There is renewed interest in field beans as an energy and protein source. Extrusion of raw ingredients can increase their nutritional value. It was hypothesized that propionic acid-treated field beans can be used to replace SBM in finisher diets and that extrusion of field beans will improve their nutritional value. Three experiments were conducted to determine the effect of extrusion of field beans on energy and crude protein digestibility (in-vitro and in-vivo), growth and carcass quality of grow-finisher pigs. Field beans are a good energy and protein source and can be fed at up to 37% inclusion in pig diets. Extrusion of field beans increased the digestible energy (DE) value, decreased the digestible crude protein (dCP) value of field beans, and had no effect on pig growth. ABSTRACT: The in-vitro ileal digestibility of dry matter (DM), organic matter (OM), and crude protein (CP) of field beans treated with propionic acid (trFB) and extruded trFB (exFB) was determined in experiment 1. The DE and dCP values of trFB and exFB were determined using the difference method in experiment 2. The effect of replacing SBM with trFB and exFB in grow-finisher diets on growth, carcass quality, apparent ileal digestibility (AiD), and total tract digestibility (ATTD) of DM, OM, gross energy (GE), and CP were investigated in experiment 3. In exp. 1, in-vitro digestibility of exFB compared to trFB was unchanged for DM (p = 0.12), increased for OM (p < 0.05), and increased for CP (p < 0.05). In exp. 2, the DE value of trFB and exFB was 14.38 and 15.75 MJ/kg respectively; and the dCP value was 21.35% and 21.42% respectively (on DM basis). In exp. 3, ADFI was higher for pigs fed trFB and exFB compared to the control diet (CON; p < 0.05), while ADG, FCR and carcass quality parameters of pigs did not differ among treatments (p > 0.05).