The aim of the thesis was to analyse the reproduction performance of sows achieved in selected breed. In the reporting period were on average born 12.6 total-born piglets, of which 11.7 live-born piglets. The highest number of live-born piglets was born of hybrid combination sows (CLWCL)CLW, 12.0?3.1; compared with sows CLWCL (11.8 ? 3.0) and CLW (11.6 ? 3.2). The most of live-born piglets were demonstrated from 3rd and 4th parity (12.6 ? 3.1 and 12.5 ? 3.1). Gilts at the age of first mating at 230 to 250 days, reached a higher number of live-born piglets (9.9 ? 2.8) compared to gilts with the age of first mating to 229 days (9.5 ? 2.5). Difference of 0.4 piglet was statistically highly significant. Sows with gestation length to 114 days had 1.3 piglets more (12.0 ? 3.1) than sows with gestation length 115 days or more (10.7 ? 3.1). Difference of 1.3 piglets was statistically highly significant. Sows weaning-to-conception interval within 4 days showed a higher number of live-born piglets (12.3 ? 3.0) than sows with 5 days or longer (11.4 ? 2.9). Difference of 0.9 piglet was statistically highly significant. Effect of farrowing interval (132145, 146160 and 161200 days) on the number of live-born piglets (12.1 ? 3.1; 12.2 ? 3.1 and 12.2 ? 3.2) was not statistically significant.