10 May 2024

Financial benefit of a good litters per sow per year

Litters per sow per year is an important key performance indicator (KPI) that farmers should benchmark themselves with and try to improve in order to minimise production costs and maintain competitiveness, writes Louise Clarke, Teagasc Pig Development Officer.

Litters per sow per year (LSY) is a calculated figure representing the number of times, on average, the sows in a herd farrow each year. This economically important KPI is an evaluation of the reproductive performance of sows in a herd.

Litters per sow per year is determined by the length of pregnancy, length of lactation, weaning to service interval and the number of non-productive or empty days.

What is a reasonable target for litter sow per year?

The maximum litters per sow per year that can be achieved for units with a 28-day weaning age is as follows:

• 115 (gestation) + 28 (lactation) + 6 (weaning to service) = 149 days
• 365 days ÷ 149 days = 2.45.

However, due to a number of circumstances (e.g. increase in empty days, increased lactation period, health problems etc.), a good average/target for empty days is 11 days (6+5) which would give you a litters per sow per year figure of 2.37.

What are the cost associated with the difference in litters per sow per year?

If we analyse two 600 sow units; unit A has a LSY figure of 2.28 and unit B has a LSY figure of 2.38. What will be the cost of this difference?

If we assume the average weaned/litter is 12.2 and each unit had a combined post-weaning mortality of 4% then:

• Net alive per litter: 12.2 weaned – 4% mortality = 11.71 pigs sold per litter
• Pigs sold/year @ 2.28 litter/sow/year: 2.28*11.71*600 sows = 16,019 pigs/year sold
• Pigs sold/year @ 2.38 litter/sow/year: 2.38*11.71*600 sows = 16,722 pigs/year sold
• Difference in pigs sold per year = 703 pigs

If these missing pigs had been brought to slaughter (88kg dwt. @ €2.24/kg), then this equates to €138,575 in lost sales revenue on an annualised basis for unit A.

What are the main components involved in achieving a good target?

1. Target a farrowing rate of 90%. Factors such as accurate oestrus detection, increasing conception rates, reducing empty days and having component skilled staff will all help to achieve this figure.
2. Reducing weaning to service interval and empty days: weaning age; sow body condition post weaning; parity; feed and water intake during lactation; temperature of farrowing room and feed intake from weaning to first service. Also, early detection of NIPs is critically important as a NIP discovered at 80 days is equivalent to four regular repeats. Good management and attention to detail on each of these points is critical.
3. Management of the service area: increased boar exposure; good semen storage techniques; good culling policy; excellent gilt management; and avoid stress as much as possible.

Conclusion

In conclusion, LSY can have a substantial difference to farm income. However, there are a number of factors that can impact this KPI, but careful management and attention to detail on the sow herd performance will pay dividends.

For more information on improving your LSY listen to the Pig Edge podcast episode with Pat Varley, where he discusses ways to improve LSY.

This article first appeared in the Teagasc Pigs newsletter for April. View the full publication here.