Effects of the type and level of supplementation on grazing behaviour of lactating ewes in a Mediterranean natural pasture

Forty Sicilian lactating ewes grazing on natural pasture were supplemented with the same hay and two concentrates characterized by different potential carbohydrate fermentability: a maize-based (C1, less fermentable) and a barley- and wheat-based (C2, more fermentable) supplement, at two levels of administration (350 g: L; 700 g: H). C1 gave rise to a higher pasture dry matter intake (mean values: 60.0 vs. 51.0 g/kg P-0.75; P<0.01). Intake was negatively correlated to the level of supplementation (mean values: 59.0 vs. 52.0 g/kg P-0.75, respectively, for L and H; P<0.05). Biting rate was not affected by either type or level of concentrate. Treatments significantly influenced the botanical composition of diets selected at pasture: the ewes fed C2 selected a higher quantity of Cruciferae than those fed C1 (34.3 vs. 24.3% FM; P<0.01). Milk production and live weight changes were not modified by experimental treatments.