Farrowing rate is one of the Key Performance Indicators (KPIs) used in the Swine Management Services’ (SMS) database. It also has one of the flattest KPI bell curves (Chart 1).
Farrowing rates range from less than 64% to 94% for the most current 52-week period that data has been summarized. The top 10% of farms averaged 88.5%, while the bottom 25% averaged 78.1%. All farms in the SMS database averaged 82.9%.
There are three main variables that impact the success of a mating/service – the sow or gilt, the semen quality, and the skill of the person doing the insemination. We refer to these variables as the SMS Fertility Triangle (picture 1).
If all three variables have a 90% success rate, you will achieve a 73% farrowing rate. To get a 90% farrowing rate, all three variables must be successful 97% of the time – which doesn’t leave much room for error.
Let’s look at the three variables individually:
- Sow/gilt – Some of the variables that affect farrowing rate include gilt’s age at first service, skip heat (gilts), parity, body condition, wean-to-service interval, number of services, boar stimulation, gestation housing, current health status, etc.
- Semen quality – Variables include boar differences, on-farm collection vs. commercial (delivered) semen, skill of the person doing the semen collection and processing, semen extender used, proper cool down of semen before shipping, semen transport procedures, semen receiving procedures, delivery temperature, proper handling and storage, age of semen at insemination, volume of semen/dose, biosecurity, etc.
- Inseminator’s skill level – Some variables include level of inseminator training, heat detection abilities, following standard operating procedures (SOP’s) for insemination, experience level, stimulation of female in estrus, type of insemination rod, personality, etc.
Generally, you have no control over how the semen was handled before you receive it, except in choosing a semen source. Your control starts with the receiving and storage SOP’s you’ve established at your farm.
You have partial control of the person(s) responsible for inseminations. Although you provide proper training and set breeding protocols, you have little control over how that person feels or the patience he/she brings to the process.
Therefore, if one of the three variables is subpar, you will get lower than expected farrowing rates. It is important to have standard operating procedures for all aspects related to farrowing rate. Those responsible for inseminations need to be caring people who show up on time and do their job well, ask questions when needed, and are not there just for a paycheck every two weeks.
At SMS, we have found that recording some additional information can be very helpful, such as: sow/gilt identification, semen batch code, inseminator name/number and time of insemination (military time). This additional information allows us to evaluate farrowing rate by the sow, by the batch of semen, by the inseminator. This information helps identify which area of the fertility triangle needs the most attention. We have created reports to analyze each inseminator, assigning a farrowing-rate-by-day-of-the-week score, and a farrowing-rate-by-hour-of-the-day score. These scores help determine who needs additional training.
Keep in mind – a 4% improvement in farrowing rate equals 1.35 pigs weaned/mated female/year.
Key Performance Indicators
Tables 1 and 2 (below) provide 52-week and 13-week rolling averages for key performance indicators (KPI) of breeding herd performance. These tables reflect the most current quarterly data available and are presented with each column. The KPI’s can be used as general guidelines to measure the productivity of your herd compared to the top 10% and top 25% of farms, the average performance for all farms, and the bottom 25% of farms in the SMS database.
If you have questions or comments about these columns, or if you have a specific performance measurement that you would like to see benchmarked in our database, please address them to: [email protected] or [email protected].

Click to view graphs.
Mark Rix and Ron Ketchem
Swine Management Services LLC