Department of Agrarian Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
(Manuscript received 18 March 2022; accepted for publication 20 May 2022)
Abstract. A total of 20 popular technical and technological schemes of semi-open four-row buildings for dairy cows with widths in the range 20.60-31.00 m have been analyzed. The options have been grouped according to the internal distribution of the buildings. Their technological flexibility has been determined and a preferred range of widths with a maximum has been outlined. For the individual studied options the costs for the technological profile of the floor (including the stationary equipment) have been calculated, as well as costs for the construction of the zero cycle, the bearing and enclosing constructions of the building have been excluded. For each preferred width, the material consumption of the floor profile has been assessed according to the construction indicators: consumption of concrete and steel (reinforcement – for reinforced concrete pavement and profile – for technological equipment), related to 1 m2 of built-up area and one slaughterhouse. A methodology for qualitative assessment of technological flexibility has been developed taking into account the impact of these costs. It has been established that the buildings with widths in the range of 25.20-25.40 m have the greatest technological flexibility. Buildings with widths in the ranges of 23.20-25.20 m and 25.80-28.00 m with equal flexibility also have very good indicators. According to the developed methodology, the widths with the same technological flexibility differ in the assessment of the impact of the costs for the floor profile – to greater extent for larger width ranges. The buildings with widths of 25.20 m and 25.40 m with maximum technological flexibility are practically equivalent, and the differences in estimates taking into account the impact of total costs of concrete and steel per 1 m2 built-up area of the floor at widths 23.20 m, 25.80 m and 28.00 m are 2.1-4.0%. For the same widths, the estimates, taking into account the impact of the total cost of concrete and steel for one cattle ranch, are from 6.5 to 15.9%. The developed methodology is recommended for the practice for assessing the impact of the costs of the floor profile on the technological flexibility of buildings with a large capacity for free-box breeding of cows. Of the four-row buildings, those with widths in the range of 25.20-25.40 m and width 23.20 m are recommended.