The research included a total of 921 lambs, 474 ewes and 8 sjenicke sheep rams from 4 different farms. The aim of the research was to examine the influence of the farm, cultivation technology and the influence of rams within the farm on production indicators. Statistical analysis showed that the body weight of lambs at birth ranged from 3.37 to 4.03 kg (average 3.68 kg), at 30 days from 11.51 to 12.41 kg (average 12.07 kg) and from 90 days from 27.82 to 29 kg (average 28.65 kg). A statistically highly significant influence of the farm was determined (P<0.01) on the body weight of lambs in all three control periods, as well as on the body weight of sheep and on the fertility of sheep. The influence of the ram on the body weight of the lambs at birth was statistically very significant within the farm (P<0.01). When it comes to the percentage share of birth type by farm, farm 1 had the most singletons (59.13%) both within the farm and in comparison between other farms, while there were fewer twins (40.87%), and triplets were not identified. On the other farms, the percentage of twins was the highest, and triplets were also present, while on farm 4 there were also quadruplets, lambs born as quadruplets (3.28%).

Lipska sheep is an autochthonous Serbian population from the group of Pramenka (Zapfel) sheep, bred in the area around Smederevo, Pozarevac and Mladenovac. The average weight of male animals (BW) is 95 kg and 62 kg of female animals. Other measurements of female animals are: wither height (WH) 74 cm, body length (BL) 78 cm, chest width (CW) 23 cm, chest depth (CD) 40 cm and hearth girth (HG) 91 cm. In the last sixty years, adult female animals gained in average ten kilograms of weight. Other linear measures also increased. The increase is a consequence of better animal management, especially improved diet. Since the reduction of the size of the population, larger animals have dominated, which probably caused the change in the genetic constitution of the breed. Female animals of Lipska sheep are higher compared to the animals of other fifteen Pramenka breeds with the exception of Istrian sheep. The area from which Lipska sheep originates has better soil and richer vegetation compared to the areas of other Pramenka breeds. Partial correlations corrected for weight between individual linear measures were positive, with values between 0.196 and 0.814. Most correlations range between 0.30 and 0.55. Body measurements were studied with ANOVA on females only. The effect of flock influenced all linear measures with the exception of CW, whereas the age of animals had no effect on BL, CW and CD. The increase of individual linear measures was 0.5 to 2.1 mm per kg of BW. The increase of most body measurements from the first to the fifth year was statistically significant (P<0.05).