Pig-farming has a long tradition in Hungary, most significantly within the Alföld region. In my analysis I studied the lifespan of sows in two nucleus pig herds on the Great Plain, also examining the probability of the occurrence of different reasons for culling. During my research I collected data (from 2001 to 2010) relating to more than 10,000 sows from the farms conducting a breeding programme and I searched for the answer to the question of whether can I find a significant difference in the lifespan of sows with the same feeding and the same genotype if the floor type of farms is different (Herd A has a solid floor with straw and Herd B has a slatted floor). Regarding the reasons for culling ANOVA was used to investigate mean differences in logarithms of the lifespan of sows in each herd. Between the herds the seven most common culling reasons were estimated with the Kaplan-Meier method and the significant difference was demonstrated with the logrank test. The results of the log-rank test showed that there was a significant difference in leg problems as a cause of culling and deaths (p < 0.05) between the two farms, which is the consequence of different floor types.