Keeping sows cool can improve farrowing rates, according to a new study looking at the factors contributing to seasonal infertility.

Findings from the study, carried out by the University of Leeds, are available in a new BPEX 2TS Research into Action factsheet.

It was found that a period of warm weather resulting in an average temperature above 18C during lactation and weaning, resulted in lower and more variable farrowing rates than when the temperature was below 18C.

BPEX knowledge transfer manager Colin Stone said: “Sow heat production increases as lactation progresses in line with increasing milk production. Therefore heat production, and so susceptibility to developing heat stress, is greatest just before weaning.

“This research suggests that cooling facilities should be provided to outdoor sows when daily average temperature rises above 18C.”

Producers are advised to adopt the following management procedures:

• Monitor sow feed intake in warm weather, and if they are not eating, take steps to cool them down or provide more energy-dense feed.

• Provide wallows early in the year and throughout the summer, or sprinklers for sows to cool down in.

• Paint farrowing arcs white to reduce the sunlight and reduce the temperature inside – this can reduce temperatures inside the arc by around 7C.

• The study will now look into how topography and staffing patterns effect seasonal infertility.