Farmer Focus: Weighing improves gilt conception rate

I’ve previously mentioned we doubled our herd to 540 sows in 2018. To achieve this at the pace we wanted, we obviously needed to select a larger number of gilts.

The challenge is always to maintain the high standards set on the previous lower scale.

Conception rates were always around 80-90% and higher, but expansion saw a dip in performance over quite a period.

I don’t think it could be pinned down to a single issue, due to the number of changes made in such a short space of time.

See also: Guide to maximising conception rates in gilts

About the author

Jack Bosworth
Livestock Farmer Focus writer Essex pig farmer Jack Bosworth farms 263ha of arable and a 540-sow farrow-to-finish operation in partnership with his family. About 60% of pigs are finished at home and 150 are sent to a farm in Norfolk to finish on a bed and breakfast contract.
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Time and patience were required to allow the animals to adjust to electronic sow feeding stations, environmental changes and being housed in two large dynamic groups.

Earlier this year we invested in electronic weigh scales to collect more data on our breeding gilts. In doing this, we have been gained more confidence around gilt weight and age (days) at service.

The difference in both conception rates and the number of piglets born alive in a litter is vast when considering the small difference between each category analysed.

When looking at age, gilts served at 241-244 days have a poor conception rate of 71%, with 13.2 born alive. The best performance has come from 250-days of age at service with a conception rate of 92.31% and average liveborn of 13.3.

We have also seen good results at 261-265 days with a respectable conception of 80%, but a fantastic liveborn of 15.9, albeit with a smaller pool of gilts.

In terms of weight at first service, gilts weighing 141-145kg have a conception rate of 92.31%, but the liveborn a litter average is 11, whereas gilts weighing 161-170kg have a conception rate of 93.94% with an average liveborn of 14.

At the other end of the scale, anything weighing more than 175kg at service has an average conception rate of 74.03% and an average liveborn of 10.67.

Since we have started weighing, the gilt conception rates are at 82.97% with an average liveborn of 14.2 a litter.

Providing the average is steadily improving, I know that Alex and Zoe – our stock people in the breeding unit – are using both their knowledge and the data to find the optimum age and weight for the gilts.