Preliminary assessment of chemical and nutritional value, and biomass production of an area in Centre-South Italy grazed by equines

Grazing ecosystems can be affected by several factors, including territory and herbivorous species reared and managed, which could influence plant diversity and pastures’ nutritional value and quality. The study of Apennine pastures in Capracotta municipalities (41°50′N 14°16′E, Isernia province), a Special Area of Conservation (SAC, IT7218215) in a mountainous area (1150-1500 m of altitude), investigated dynamics in pasture areas characterized by widespread presence of rock outcrops. During spring and summer grazing season 2024, pasture biomass was evaluated in six sampling sites, grazed by Italian Heavy Draught breed horses, by 24 representative sub-areas. In each sub-area, biomass was manually collected at 3 cm above ground to simulate grazing. The dried biomass underwent chemical analyses including dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and ash. Antioxidant activity, as mg of ascorbic acid equivalents (AAE)/g DM, was assessed by 2,2′-azinobis-(3-ethylenebenzothiazoline)-6-sulfonic acid (ABTS) assay. Total phenolic content (TPC), as mg of gallic acid equivalents (GAE)/g DM, was quantified by the Folin-Ciocalteu method. The average (±SE) turf production was 2.82 (±0.19) t DM/ha. The pasture, mainly composed of grass and legume plants, was characterized by DM 34.3 (±5.75) g/100g, CP 6.43 (±0.41) g/100g DM, ash 8.82 (±0.17) g/100g DM, NDF 48.1 (±1.73) g/100g DM, and ADF 30.6 (±0.93) g/100g DM. The average (±SE) ABTS content was 3.17 (±0.06) mg AAE/g, and TPC 2.32 (±0.09) mg GAE/g. Antioxidant activity varied significantly (p<0.001) among sites: sites 2 and 3 recorded in spring the highest values at 3.62±0.07 and 3.75±0.07 mg AAE/g, respectively, according to the highest TPC content (3.03±0.04 and 2.97±0.11 mg GAE/g). Overall, both antioxidant activity (3.40±0.04 mg AAE/g) and TPC (2.63±0.05 mg GAE/g) were higher (p<0.001) in spring than in summer (2.48±0.07 mg AAE/g and 1.41±0.08 mg GAE/g). Results suggest the impact of site and season variations on pasture value. Assessing pasture characteristics with a comprehensive evaluation of equine breeding systems will improve breeding models to enhance the resilience of marginal areas, especially in Centre-South Italy. The research was supported by PRIN project 20224L4WSR Sustainable Innovations in Equine Production of Marginal Areas (SUNEQUMAR), funded by Next Generation EU. (CUP: H53D23005120)