Economic comparison of insemination and culling policies in commercial sow herds, assessed by stochastic simulation.

Abstract

The simulation model considered 3 culling policies and 3 insemination policies. Culling was classified into unplanned disposal (e.g. fertility, diseases) and planned culling, with a total disposal rate of 55%. The 3 planned culling policies were (1) culling of the oldest sows, (2) culling of sows with the lowest Retention-Pay-Off (RPO, an economic index which ranks sows on future profitability), and (3) culling of sows with the lowest RPO but with the proviso that replacement gilts can also be culled. The 3 insemination policies were: (1) a maximum of 3 inseminations per parity; (2) a maximum of 3 inseminations for parities 1 to 4, 2 for parities 5 to 7 and 1 for sows in other parities and gilts; (3) the number of inseminations depends on the sow's RPO, with a maximum of 3. It was found that culling decisions had a greater effect on profitability than insemination choices. The 3rd culling policy gave the highest profit and the 1st the lowest. It was also shown that the planned disposal rate should be at least 10% of all disposals to yield positive economic effects. (Abstract retrieved from CAB Abstracts by CABI’s permission)