Pisum sativum L. as an alternative protein and starch source in Italian Mediterranean buffaloes’ feeding plan: in vitro evaluation of different varieties

Soy and its by-products are the main protein source in animal diets. This study evaluated the partial substitution of soybean meal (SBM) and corn meal with pea grain in buffaloes’ diets through two in vitro trials. In the first experiment nine pea grain commercial varieties (Aviron, Furious, Ganster, Lapony, Lump, Mowgli, Myster, Peps, Poseidon) were incubated over 48 h to assess their nutritional characteristics. Results showed significant variation among the varieties, with a high organic matter digestibility (>90%) and protein degradability (>50%), except for Mowgli variety. After multivariate cluster analysis, Ganster, Poisedon and Peps were selected for the second trial in function of highest organic and protein degradability. In the second experiment, the three best-performing pea grain varieties were each one incorporated into three diets similar for protein and energy content (Ganster, PSG; Poseidon, PSP; Peps, PSE), compared to a control diet (CTR) based on SBM and corn meal. The PSP and PSG diets significantly improved organic matter degradability. No one of experimental diets affected protein degradation. The PSE significantly decreased gas production (OMCV), while all experimental diet decreased gas production when related degraded organic matter (yield). All experimental diets showed higher fermentation kinetics than control diet. The PSP, PSG and PSE increased butyrate production while PSP and PSG increased branched-chain fatty acids. Overall, pea grain not only serve as a protein source but also as an energy supplier, potentially reducing the need for additional high-energy ingredients.