Variazioni della composizione chimica di un pascolo naturale destinato all'allevamento di cavalli allo stato brado: confronto fra due annate successive.

In Molise Region (Italy) wild horses named "Pentro horses" (autochthonous population) are still bred. The breeding area is a natural pasture. It is 2200 ha extended including a broad plane surrounded by wooden hills. This paper is part of a research project concerning the study of the nutritional characteristics of all the area over a two years period. The aim is to improve the management of the herd and to define the stocking rate in order to prevent the risk of extinction of the equine population without compromise botanical features of the area. This paper shows the variation of the chemical composition of the grass during the grazing period (May to October) over two following years. The forage samples were collected from 5 experimental areas that represent the prevalent land typology (2 for the pasture system and 3 for grazing meadow system) according with the Corral and Fenlon method (1978). Dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and gross energy (GE) were determined. Data were analyzed with a one-way ANOVA test using month and area as factors. The results show that seasonal and yearly climatic variations significantly affect chemical composition of the pasture. In particular, the most influenced parameters are DM, CP, ADF and to a less extent NDF, while OM, ADL and GE show smaller differences during the observed period. The differences among the areas have to be ascribed to the different botanical composition and to the different draining capacity of the soil and also in this case the greatest variations are for DM, CP and ADF. Since these parameters are those that more influence the nutritive value of the pasture, it seems possible that during the most critical months (July-September) the requirements of the herds could be unsatisfied. For this reason, in that period a different management of the herd (hay integration, pasture rotation) should be examined to avoid pasture and soil degradation.