Semen Quality’s Impact on Farrowing Rate

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) in the database.

There are three main variables that impact the success of a mating/service – the sow (gilt), semen and the artificial insemination (A.I.) technician. We refer to these variables as the SMS Fertility Triangle. This week we will focus on semen quality.

Semen quality can be affected by many variables, such as on-farm collection vs. purchased semen, semen transport method, semen receiving procedures, temperature of semen at delivery, on-farm handling and storage, temperature control of semen storage unit, type of semen extender, age of semen at insemination, volume of semen/dose, individual boar vs. pooled semen, biosecurity, etc.

To effectively evaluate the quality of the semen, the following information is needed:

  • Breeding information records: sow/gilt identification, semen batch code, insemination technician name or number and time of insemination (military time 1-24).
  • Semen temperatures: use an infrared thermometer to record the temperature of semen at time of delivery, checking several of the semen bags or bottles. Keep a 24-hour log of high/low temperatures in your semen storage unit. For more accurate data, use a digital indoor/outdoor, minimum/maximum temperature station.
From this additional information, SMS has created reports that record farrowing rate of each batch of semen/boar, farrowing rate by each inseminator broken down by parity, day of the week and time of insemination, number of matings and number of services.

Chart 2 features farrowing results from 230 boars (multiple farms and boar studs combined). Farrowing rates by boar range from 60% to 95%, with an average of 82%; 99 boars of the 230 farrowing rate averages was below the average of 82%, which represented 45 % of the doses. If you are not recording this type of detailed information, you cannot effectively analyze farrowing rate.

The semen temperature at delivery should not vary more than 2 degrees above or below the temperature when it left the supplier. If temperature variation exceeds that range, alert your semen supplier so they can review their standard operating procedures for packing of semen, cooling semen before packaging, and handling by the delivery person/company transporting the semen to your breeding facility. And remember, receiving warm semen and placing it in your semen storage unit with older semen can raise the temperature of all the semen in the storage unit affecting quality.

Daily monitoring of the high/low temperatures of the semen storage unit helps confirm the unit is working properly, records the day-to-day fluctuation in the storage unit, documents the ability to handle large shipments of semen, records the impact of extremely hot or cold temperatures, whether the storage unit door was left open, or if the power was interrupted.

Temperature fluctuations in storage or during transport can have a big effect on boar semen fertility. Discussions with reproductive experts and artificial insemination technicians and a review of the literature have provided this checklist:
  • Semen extender: Make sure your storage unit is set at the temperature suggested by the semen processor. Some of the new extenders should be set at 60° F. (15.56° C)
  • Semen stored too hot: Excessive heat will probably shorten the length of time the extender is effective. A five-day extender may only be viable for three days when exposed to heat.
  • Semen stored too cool: Cold shock will reduce the number of viable sperm.
  • Semen exposed to fluctuating temperatures: Temperature fluctuations during transport or in the storage unit can affect the length of time the semen is usable. Poor quality semen, regardless of the cause, will reduce subsequent farrowing rate and litter size.
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: or

Click to view graphs.

Mark Rix and Ron Ketchem
Swine Management Services LLC