Fermentation and enzymatic treatment of pea for turkey nutrition

The present study was conducted to investigate how fermentation (FE) and enzymatic treatment (ET) of pea affect standardized ileal digestibility (SID) of nutrients in diets with peas as the only protein source, and evaluate the consequences of inclusion of different pea products in turkey diets (100 g/kg) on growth performance and bird health. For FE process, Pisum sativum L. was mixed with water (1:1) containing 4.9 × 108 Bacillus subtilis and licheniformis spores/kg pea (BIOPLUS 2B®, Chr. Hansen, Denmark). The prepared dough was fermented for 48 h at 30 °C. For ET, the dough water contained three enzymes, AlphaGal™ (α-galactosidase – Kerry, USA), RONOZYME® ProAct and VP (protease and pectinases, respectively – DSM, Switzerland). The dough (500 g/kg DM) was incubated for 24 h at 30 °C. Both processes reduced α-galactosides, phytate, trypsin inhibitor activity and resistant starch in peas. For standardized ileal digestibility (SID) assay, 288 turkeys were assigned to 24 pens and received four experimental diets including native (NP), fermented (FEP) and enzymatically treated peas (ETP) as well as a N-free diet (all supplemented with vitamins and minerals). The ETP had better SID of protein, Glu, Phe and Val compared with FEP and NP. Enzymatic treatment of pea also improved standardized ileal digestibility of Ala, Gly, His, Ilu, Leu and Lys (P ≤ 0.05), however digestibility of these nutrients in fermented pea were similar to other two types of pea (P > 0.05). Both processes drastically improved ileal digestibility of starch (P ≤ 0.05). For performance trial, 960 turkeys were allocated into 60 pens and received 4 different diets consisted of a basal mash wheat-SBM diet (CON) and there experimental diets which were prepared by inclusion of each pea products NP (NPD), FEP (FEPD) and ETP (ETPD) in the basal diet at the rate of 100 g/kg. The experiment lasted 105 d. In general, in the most time periods of the performance trial, birds received ETPD or FEPD diets showed better growth performance than those fed NPD diet, while birds in ETPD group displayed similar performance to those fed CON diet. At the end of the trial, birds fed CON and ETPD diets had the best FCR and birds which received NPD diet had the worst one (P ≤ 0.05). Birds in ETPD group showed the best footpad dermatitis score and turkeys in the NPD group had the worst score (P ≤ 0.05). The footpad dermatitis scores for turkeys in CON and FEPD groups were identical and considerably different from those in ETPD and NPD groups (P ≤ 0.05). In conclusion, both processes could improve the nutritional quality of pea by reduction in ANF and increasing ileal starch digestibility. Furthermore, ET process considerably improved SID of protein and AAs in pea. Inclusion of ETP in turkey diets (100 g/kg) demonstrated neither positive nor negative impact on growth performance, while it remarkably improved footpad dermatitis score. The present data shows the feasibility of these processes, particularly ET, for improving the nutritional quality of pea as a protein source for turkey diets.