Raw and extruded pea (Pisum sativum), faba bean (Vicia faba var. minor) and lupin (Lupinus albus var. multitalia) as alternative protein sources in broiler diets

Research on vegetable-based protein sources has grown as a result of the European Union ban on the inclusion of meat and bone meal in diets of agricultural livestock. This together with recent concern over genetically modified soybeans, the protein source of choice for monogastric diets, has sparked research into the identification of some alternative protein sources. The objective of this study was to evaluate the effect of raw or extruded pea (RP and EP), faba beans (RFb and EFb) or lupin (RL and EL) in partial substitution of soybean meal and other starch sources in broiler diets. A total of 462-d-old male Ross chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens/treatment). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The amount of alternative proteins used as fed basis and for 1-10 d-old and 11-42 d-old growing periods were: RP and EP: 350 g/kg for all diets; RFb: 480 and 500 g/kg; EFb: 240 and 250 g/kg; RL: 360 and 300 g/kg; EL: 180 and 150 g/kg. Feeds were analyzed for tannins, polyphenol, genisteine, and daidzeine contents and the in vitro alpha-amilase starch digestibility was measured. At the end of the trial performance parameters were calculated, animals were processed and percentage yields (one per pen) of breast meat and leg quarters were quantified. The polyphenol concentrations and antitrypsin activity were reduced and the alpha-amylase digestibility increased in EP and EFb. The feed conversion ratio was not significantly affected, however, the feed intake was reduced (P<0.01) in EL diet compared to the control group and to the RL diet. The RP group had lower dressing percentage (P<0.05), whereas groups fed faba bean had higher breast yield (P<0.01) independent of processing. There were no statistical differences in percent yield of the leg quarters. Data support the utilization of these alternative proteins sources into broilers diets as a viable solution to counteract the current constraints of soybean meal. Partial improvement was seen with EFb and EP, which was not seen however for the lupin based diets.