Three Main Variables to Improve Farrowing Rate

Improving farrowing rate has economic value to your sow farm. Improving farrowing rate by 4% will increase pigs/sow/year by approximately

Improving farrowing rate has economic value to your sow farm. Improving farrowing rate by 4% will increase pigs/sow/year by approximately 1.35 and reduce the breakeven by approximately $1.75/weaned pig. That 4% would also allow you to reduce sow inventory by approximately 5% while producing the same number of pigs and reducing the breakeven by approximately $0.25/ weaned pig.

Swine Management Services’ Fertility Triangle (Figure 1) shows the three variables in breeding: female (sow/gilt), boar semen (quality), and person (Artificial Insemination Technician). We have discussed these key factors in previous Weekly Preview columns. We feel it would be good to summarize the key performance measures and standard operating procedures (SOP) into one document. The following should be part of your farm’s SOP manual:

Female (sow/gilt):

• Gilt development should include 1-2 recorded heat cycles before breeding and weigh 300 lb. or more. Place gilt candidates in stalls so they can adjust before breeding.

• Wean-to-1st service interval should be in a range of 4.5-6 days, based on weaning age of the pigs

• Daily feed intake in lactation must be at least 14 lb., based on the number of pigs nursing with special attention to Parity 1 females.

• Daily water intake should be 5-10 gallons; nipple flow rate should be at least 2 quarts/minute.

• Newly weaned sows need extra feed from weaning until breeding; we suggest a second feeding of 3-5 lb./day, depending on body condition.

• Provide supplemental cooling for all sows and developing gilts when temperature exceeds 78° F.

• Review records by parity, wean-to-1st service interval, number of matings, number of services, regular returns to estrus and irregular returns to estrus. Boar Semen: • Check temperature of shipped semen at delivery to ensure it is within +/- 2 degrees of desired semen storage temperature.

• Record high/low temperatures of the semen storage unit daily to monitor variation. Temperatures should not vary more than 2-4 degrees F. Make sure semen storage unit is located in an air-conditioned area maintained at 70° F or less.

• On-farm semen collection and processing must have written SOPs for sanitation, collection, extending, evaluating, and at least quarterly semen testing for semen concentration and bacterial contamination.

• All SOP’s should be written specific to the semen extenders being used. Some new extenders require lower semen storage temperatures.

• Retain records so you can evaluate each batch of semen for farrowing rate. Share this information with your semen supplier and on-farm processing team and artificial insemination (AI) technicians. AI Technician • Begin exposure to a mature boar on Day 1 after weaning. Check for estrus before Day 4 after weaning. Your records should be used to determine if you need to breed these early cycling females or skip them.

• Train new employees using you SOP’s for the breeding area. When breeding SOPs are changed, be sure to (re)train all AI technicians and monitor the results. If changes are positive, update the SOP’s for the farm.

• The number of services needs to be monitored and females returning twice should be culled.

• The percentage of multiple matings should be 98% or higher; this may require AM/PM matings on gilts, returns to estrus and late weaners to lower the number of single matings and improve farrowing rate. There needs to be at least six hours between the AM and PM matings.

• Collect detailed records to evaluate each AI technician’s performance by status of female, number of matings, number of services, parity, hour-of-day matings and day-of-week matings.

All procedures of the breeding area must be written in your SOP manual. These SOPs must be developed by the management staff and those working in the farm. If they are included in developing the procedures, they will take more ownership in them.

Key Performance Indicators

Tables 2 and 3 (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

Mark Rix and Ron Ketchem
Swine Management Services LLC

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