Survival analysis of culling reasons and economic examination of production period in sow culling

The culling of the sows is an important task of the breeders and farmers, besides it is a determining factor of profitable pork production. During our research we have surveyed the data of 1969 sows in a Hungarian large-scale pig farm. For the calculation of our results we used one of the non-parametric forms of survival analysis, the Kaplan-Meier analysis. For the quantification of death intensity we applied another survival analysis model, the log-rate exponential model. We have found out the risk values of various culling reasons form the point of view of culling. Besides, we tried to quantify by an economic model how the production period of sows influences the average costs of piglets and the average costs of piglets per kilo at 2006 prices. We calculated that the 5th farrowing is the minimum cost place.