Agricultural Institute, Radnevo road, 6000 Stara Zagora, Bulgaria
(Manuscript received 11 July; accepted for publication 01 September 2022)
Abstract. Selection is an important part of animal breeding and is usually performed on the basis of a set of traits, each of them characterized by its BV (breeding value) and EV (economic value). Different approaches have been used in recent years for the calculation of the economic values of traits – simple profit functions and more complex bio-economic models. The most common approach nowadays is the bio-economic modeling of the production system due to its precision, flexibility, the inclusion of many biological details reflecting the changes in genetic values on overall profitability. The objective of this review is to present and summarize research on calculation of economic values for dairy, meat and indigenous (multipurpose) sheep breeds using bio-economic models. According to the type of sheep production, various productive and functional characteristics have been studied. Of particular importance for the predominance of a particular trait over others in terms of its contribution to profit on farms are the breed, production system, climatic conditions, market determinants, demand and supply of sheep products, etc., which may undergo changes over time. For this reason, a recalculation of the economic importance of profit-related traits in sheep is needed for the adaptation of the breeding objectives of the enterprises according to their economic importance.