Pea (Pisum sativum) and faba beans (Vicia faba) in dairy cow diet: effect on milk production and quality

The use of alternative plant proteins in place of the soybean meal protein in diets for producing animals aims to reduce the extra-EU soybean import and partially substitute the GMO in the food chain. Among possible alternatives, the heat-processed legume grains seem interesting for dairy cow diets. Two consecutive experiments were carried out to evaluate flaked pea and faba beans as substitute for soybean meal in diets for Reggiana breed dairy cows producing milk for Parmigiano- Reggiano cheese-making. In both experiments a C concentrate (110 g/kg soybean meal, no pea and faba beans) was compared to a PF concentrate (150 g/kg flaked pea, 100 g/kg flaked faba beans, no soybean meal). Forages fed to animals were hay (mixed grass and alfalfa) in experiment 1 and hay plus mixed grass in experiment 2. Concentrate intake, milk yield and milk quality (rennet coagulation traits included) were similar between feeding groups. Parameters on the grab faecal samples, as empirical indicators of digestibility, had a smaller (P<0.01) amount of residual concentrate in the PF group compared to the C group (2.4 vs 3.1 and 2.3 vs 2.8%, respectively for PF and C in experiment 1 and 2). Some blood indicators of nitrogen metabolism (protein, albumin, urea) were similar between the feeding groups.The inclusion of pea and faba beans, within the allowed limit of the Parmigiano-Reggiano Consortium for diet formulation, could represent a feasible opportunity for a total substitution of soybean.