Abstract. The purpose of the present study was to establish the economic performance of sheep farms of the Local Stara Zagora breed. Production and economic results of three private farms in southern Bulgaria were studied for 2022. Data were obtained from the farmers after filling in questionnaires. Sheep have been raised in stall-pasture system with grazing period lasting from March to November, and stall period from December to February, and one lambing per year. Revenues, costs, profit (BGN) and profitability (%) on the farms were calculated. Revenues from the sale of milk were estimated to account for 39% of gross production, and subsidies – 24% of total revenues, on average. Feed costs accounted for 56% of total costs on farms. Farm 1 and farm 3 yielded low profits estimated at BGN 8.90 and BGN 6.28 per ewe, respectively, while farm 2 operated at a loss of BGN -33.61 per ewe. Therefore, farms’ survival is at risk, and due to increasing prices of feed, energy, labour and fuels they may not stay viable in the future. In such small sheep populations maintaining instead of targeted selection is performed and particular results in improving the level of the main selection traits cannot be expected. Measures for improving nutritional management and feed efficiency are considered fundamental for the future sustainability of the breed and also adequate support must be provided to maintain the population size in the future and its conservation as valuable genetic resource in the country.

Abstract. The aim of the present study was to develop theoretical bio-economic models of Lacaune sheep farms and establish their economic efficiency. Based on three main criteria, 15 options were considered and analyzed. Data were processed using the program EWSH2 as a part of ECOWEIGHT Package for calculating economic weights in livestock. Revenues from sales, variable costs, gross margin and profitability before and after subsidies and per ewe were calculated. It was found that raising sheep of the high productive Lacaune breed could generate profit and provide profitability for the studied models of farms, regardless of the level of selection, type of production system, flock size and even the amount of subsidies. Nucleus farms reported the largest gross margin, followed by the basic and commercial farms. Profitability without subsidies showed the highest values for the nucleus flocks of 1000 ewes – 24.24% when adopting semi-intensive production system and 23.14% for the intensive one. With the addition of subsidies, nucleus and basic farms of 1000 ewes were considered the most profitable with 40% and 37.37%, as for both options the semi-intensive conditions were preferable. A tendency for the values of the studied indicators to grow with the increase in the number of ewes in the flocks was observed, as only for the variable costs it was reversed. Due to the lack of studies on economic efficiency of Lacaune sheep farms in Bulgaria, an additional detailed research, based on real data, is advisable to be conducted.