Nutrition as factor of improvement of production of sheep milk on the territory of Stara Planina mountain

Investigation was carried out on the territory of Stara Planina mountain, Pirot mnucipality, in villages: Dojkinci, Brlog, Jelovica, Visocka Ržana and Rsovci, from 700-1200 m above sea level, on farms with greater number of sheep (over 100 heads) which in regard to the breeds structure were mainly Pirot pramenka breed, and insignificant number of heads were crosses of Pirot Pramenka and Wurttemberg. Research included analysis of pasture from the aspect of floristic and chemical composition. In regard to botanical composition it was concluded that grasses were present with approx. 50%, leguminous plants with 15% , and herbaceous plants with 35%. Share of crude protein in investigated samples varied from 4,81 to 13,57%, and of crude fibre from 20,67 to 37,17%. Yield of forage on pastures was from 0,6 to 2,0 t/ha. Low yield as well as unsatisfactory floristic composition of pastures resulted from poor care, especially lack of fertilization and their unplanned and inefficient use which was reflected on milk yield of sheep, in lactation of 180 days it was from 69,16-70,40 kg. Improvement of botanical composition can be achieved by application of fertilizers since in this way the share of useful grasses (Poaceae) and leguminous plants (Fabaceae) is increased, and share of herbaceous plants in total mass of pasture is reduced, which represents one of our goals in research on the Pirot territory of Stara Planina mountain. In order to preserve the quality and phytodiversity of plant species we suggested as optimal way of pasture utilization, combination of pasture and cutting system. In winter nutrition period, on investigated locations, introduction of haylage in nutrition of sheep used for production of milk is recommended, because of its higher nutritive value compared to hay.