Changes in fatty acid profile of Bovec sheep milk due to different pasture altitude.

Sheep rearing on mountain pastures is an ancestral tradition in northwestern Slovenia. The indigenous Bovec sheep are widespread there and are well adapted to the rough Alpine rearing conditions. Every year, after weaning, the sheep start grazing in the lowlands (L) and then gradually move to mountain pastures, and finally, to the highland (H) pastures of the Alps. Grazing positively affects the fatty acid (FA) composition in sheep milk fat with increased availability of polyunsaturated FA (PUFA) in grass, and subsequently, in milk. Consequently, the objective of this work was to study the FA profile in sheep milk during grazing in four geographical areas in the Alps. A total of 15 ewes of the Bovec sheep breed were randomly selected and milk samples from these ewes were taken at four different pasture locations that differed with regard to altitude: the L pasture location at an altitude of 480 m, the mountain pastures (M1 and M2) at altitudes of 1100 to 1300 m and 1600 to 1900 m, respectively, and the H pastures at altitudes of 2100 to 2200 m. Milk samples from the ewes were taken during the grazing season from April to September. The chemical and FA composition of the milk samples from each pasture location were determined. There were significant differences in the concentrations of FA among the L, M1, M2 and H milk samples. We observed decreases of the concentrations of saturated FA (SFA) in milk from L to H pastures. The concentration of α-linolenic FA, monounsaturated FA (MUFA), PUFA and n-3 PUFA in milk were increased significantly with pasture altitude. The n-6/n-3 PUFA ratio was reduced by the change of pasture altitude with the lowest value at the M1 pasture (1.5). The concentrations of total SFA decreased significantly and was lowest at the L pasture. Our results underline the importance of the effect of grazing in the Alpine region associated with pasture altitude on the FA profile of sheep milk. The first variation in FA concentration in sheep milk occurred between L and M1, although it was more evident on H pastures in the Alpine mountains. Changes of the FA profile in sheep milk due to pasture altitude were related to variation in FA concentration in the pasture and the botanical composition of the pasture location.

Research on the influence of red deer (Cervus elaphus L.) grazing on grassland production in the south-eastern part of Slovenia.

Almost 60% of Slovenian territory is covered by forests and only Finland and Sweden are known as the more forest abundant countries in Europe. Among game that intensifies difficulties in the field of agricultural production, especially in north-eastern and south-eastern parts of the country, roe deer (Capreolus capreolus L.), wild boar (Sus scrofa L.) and red deer (Cervus elaphus L.) prevail. Negative impact of game on agricultural production in the above mentioned parts of Slovenia has risen significantly in the last decade. The data about the population density of game in Slovenia is often based on the payments of their damage on the cultivated plants that are usually performed by the hunting societies. Grassland represents around 60% of agricultural land in Slovenia, and herbage is a very important component of the red deer diet. At the forest border where ruminant ungulate animals spend most of their life, the grassland production for a farmer is often decreased because of the grazing of this hoofed animal. Hitherto, decrease of grassland productiveness from a farmer's perspective, caused by the red deer grazing, was not yet researched in Slovenia. Similar studies were also very rare in other European countries. With the intention of gathering data and learn more about the potential harmfulness of the red deer on grassland production the experiment was performed in the south-eastern part of Slovenia in the year 2002. The influence of red deer grazing on grassland production for forage conservation at the forest border during the vegetation period was studied on three locations (Mala gora, Cvislerji and Mackovec) in the Kocevje region. The experiment lasted from the third decade of March until the first decade of October. Portable cages of size 1x0.5x0.5 m were used to exclude red deer from grazing the herbage. At four sampling dates in the season herbage air dry matter (DM) yield was measured at three different observations (cage-protected plot, cage-protected plot only two to three weeks before sampling date, otherwise freely grazed--removed and unprotected plot). The results from the experiment showed us that red deer grazed on grassland through all seasons and that the regeneration capability of sward was the highest in summer, middle in spring and smallest in autumn. On unprotected plots an average 50% reduction of herbage DM yield was found with the most distant sites also up to 80% reduction.