Empty sows are the non-pregnant sows that are serviced again after 60 days post-service.
When the percentage of empty sows among the sows serviced is greater than 1% we must examine the causes.
Empty sows often result from problems with returns to estrus, coupled with a failure to detect estrus, or unseen abortions. In general, since sows in advanced gestation (more than 4 weeks of gestation) are housed in pens of different sizes, it is common for not all abortions to be detected (especially the early ones: 35 to 60 days of gestation).
When there are empty sows, it is essential to establish an early detection system in order to find the moment when the losses occur. To this end, it is recommended to increase the number of pregnancy diagnoses that are carried out, in such a way as to limit the periods of possible losses.
Here is an example of a gestation monitoring sheet for a large farm, where one can see the follow-up of the percentage of sows that remain pregnant at 28 days (before being moved to gestation pens), at 56 days (after a second ultrasound), and the final farrowing rate per week.
Use the flow chart to continue your troubleshooting or to access other parts of the tool.