Producers should focus on maintaining an optimum parity profile, by regularly replacing older or less productive sows and keeping the herd’s overall performance steady. Sow culling rates have a direct correlation with economic efficiency.

BPEX knowledge transfer manager Angela Cliff says: "Producers should aim for an average herd parity no greater than 2.8. It’s important to understand why individual sows are culled and to manage voluntary or selected culling consistently.

"Decide what your target maximum parity is for each animal and then stick to it. Voluntary culling is also carried out to remove any sows not performing as well as they should. For example, those that have shown farrowing difficulties, poor litter size or poor lactation and rearing ability."

At the same time producers need to minimise the level of involuntary or forced culling, most commonly caused by fertility problems, lameness or disease.

"Producers should continually record sow condition and performance and pay close attention to management of gilt selection, feeding strategies and pen and floor condition."

To find out the economic impact of retaining older, less productive sows, it is worth calculating the cost of ‘empty days’:

Cost per sow-day = Total annual breeding herd expenditure / (productive sows x 365)

Cost of reproductive failure = Cost per sow-day X empty days per annum / pigs born alive (sold) per sow per year

For more guidance, download the factsheet 2TS Action for Productivity no. 40: Sow culling from www.bpex.org.uk/2TS/resources.aspx or call 024 7647 8792.