Minimizing Non-productive Days

In the Swine Management Services (SMS) database, “mated female non-productive days” averages 36.4 days. The top 10% of farms average is 31.4 days, the top 25% of farms averages 30.4 days, and the bottom 25% of farms average is 41.8 days.

In the Swine Management Services (SMS) database, “mated female non-productive days” averages 36.4 days. The top 10% of farms average is 31.4 days, the top 25% of farms averages 30.4 days, and the bottom 25% of farms average is 41.8 days.

We also track “first service-to-repeat-service interval,” which is the time it takes to find recycling females after first-service breeding. The top farms find over 60% of regular returns in heat by Day 25 after mating. Our data shows 20-40% of the non-productive days come from females that fail to conceive on the first service. A female that fails to conceive can accumulate from 20-120 non-productive days if she is not identified early through heat checks or pregnancy checking. Farms that have dealt with a health problem such as porcine reproductive and respiratory syndrome (PRRS) or swine influenza virus (SIV) may increase non-productive days to 70-80 days, on average, due to late-term abortions, female deaths and late term NIP’s (not-in-pig females).

Farrowing rate is one of the Key Performance Indicators (KPIs) used in the SMS database. Chart 1 shows the variation in farrowing rate on 650 farms. Note that one farm has a farrowing rate over 96%, while seven farms have a farrowing rate under 66% for the 52-week period. It also has one of the flattest KPI bell-shaped curves. For the current 52-week period, the top 10% of farms averaged 88.5%, the bottom 25% averaged 78.2%, and the All Farms averaged 83.4% farrowing rate.

The average “percent repeat services” in the SMS database is 8.8%. Chart 2 shows the variation in percent repeat services on the same 650 farms. Data shows 38 farms below 2% and 56 farms over 17%. Because rebreeding returns for third service usually end up with farrowing rate at 40-50%, most farms have stopped breeding females that repeat a second time.

A growing number of farms are culling all repeating females, which is reflected in the under 2% group. The economics of this practice is questionable when compared to breeding the females a second time or culling higher parity females with poor production histories. The increased genetic and other related cost needs to be evaluated before putting a policy in place to cull all returns after one service.

SMS feel most of the “first service-to-repeat-service interval” days are unnecessary if the breeding staff works hard at finding those returns, starting 14 days after the females were initially mated. Chart 1 reinforces the huge variation in farrowing rates, by farm. With some changes in the breeding procedures, a 90%+ farrowing rate is definitely achievable by more farms. If you improve the farm farrowing rate by 5%, that would drop first-service-to-repeat-service interval days by 7-11/female, eliminating 20+% of the mated female non-productive days. This improvement gives the farm two options:

1. Farrow 5% more litters/week, produce 5% more pigs and lowers the breakeven by approximately 5%, however, this option would probably lower average weaning age. The 5% more pigs might affect the nursery/finishing flow negatively by transferring younger pigs and crowding the facilities.

2. Reduce the breeding herd by 5%, produce the same number of pigs and reduce the breakeven by approximately 3-4%. This option would maintain the same average weaning age and would not negatively affect the nursery/finisher flow. Some costs are fixed, such as facility costs, and would actually be higher per weaned pig. Table 1 breaks out the database by farrowing rate groups in 5% intervals. The table shows an improvement from 80 to 85% – a drop of 7.7 days in mated female non-productive days. The improving farrowing rate decreases the number of repeat services, which increases the litters/mated female/year, which affects how farrowing crates are utilized and improves the efficiency of the facility.

Lowering mated female non-productive days begins with your breeding crew directing more attention to identifying those females sooner. Again, start looking for recycling females 14 days after breeding, using aggressive mature boars, rotating heat check boars daily, working in a team of two when looking for returns. Use a flashlight to look for sows with mucus discharge. And, the most important point is – just slow down and let the boars and sows make contact with each other.

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

Click to view graphs.

Mark Rix and Ron Ketchem
Swine Management Services, LLC