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Targeting Profit-Robbing Non-Productive Days

The term “non-productive days” is readily used as a measure of breeding herd performance, but in doing so, it is important to standardize how the information is collected.

The term “non-productive days” is readily used as a measure of breeding herd performance, but in doing so, it is important to standardize how the information is collected.

We have added two lines to the bottom of Tables 1 and 2 to include non-productive days/female and non-productive days/mated female. The tables 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 Swine Management Systems’ database.

Following are a few definitions we use in defining non-productive days.

BREEDING FEMALES are mated and unmated females kept for breeding purposes.
MATED BREEDING FEMALES are females that have been mated at least once and have not been removed from the breeding herd.
MATED BREEDING FEMALE DAYS are days from the first mating until removal from the breeding herd.
UNMATED BREEDING FEMALES are females entered into the breeding herd but have not been mated.
UNMATED BREEDING FEMALE DAYS are days between entry in the herd and the first mating or entry into the breeding herd and removal from the breeding herd having never been mated.
PRODUCTIVE DAYS are days which a breeding female is either gestating or lactating. Gestation days that do not result in a farrowing are not considered productive days.
NON-PRODUCTIVE DAYS are days which a breeding female is neither gestating nor lactating.
MATED FEMALE NON-PRODUCTIVE DAYS are days which a mated breeding female is neither gestating nor lactating. At SMS, we do not compare non-productive days between farms. Instead, we compare “mated female non-productive days.” The reason is simple – there is too many variation in the way gilts are entered into the breeding herd. We work with farms that enter the gilts into their recordkeeping program when they arrive, while other farms enter the gilts at first breeding.

“Entry-to-first-service interval” ranges from 0-120 days, with an average of 25.8. We are seeing a trend of fewer farms entering gilts on arrival because of the way software companies are charging for their services on a female basis instead of on a farm basis. At SMS, we recommend entering gilts upon arrival because they are the future of your farm and there is much that can be gleaned from this information.

Another reason for using “mated female non-productive days” to compare farms is usually the manager does not control the number of “unmated female non-productive days,” which is determined by the way the gilts are entered into the records and the biosecurity protocol for the days in isolation and development.

“Unmated female non-productive days” incurs feed cost of $0.50 - $0.80/day and a yardage cost of $0.10 - $0.20/day, but this is some of the best dollars you can invest on the farm.

“Mated female non-productive days” cost the farm from $1.60 to $2.60 /day, which includes all expenses on the farm. An easy way to calculate cost for your farm is to take your breakeven/weaned pig x pigs weaned/mated female/365 days.

Example 1: $28.00 x 26.00 / 365 = $1.99
Example 2: $34.00 x 26.00 / 365 = $2.42
Example 3: $32.00 x 20.00 / 365 = $1.75
Example 4: $38.00 x 20.00 / 365 = $2.08 In the SMS database, “non-productive days/mated female” averages 36.4 days. The Top 10% average is 31.6 days, the top 25% averages 30.1 days, and the bottom 25% average s 41.5 days.

Here are some areas that affect the number of “non-productive days”:

• “Wean-to-first-service interval” is the number of days from weaning until a female is mated again. In the SMS database, the top 10% of farms are at 6.23 days, while the bottom 25% is currently at 8.49 days. This figure is inflated when managers lose track of weaned sows and then breed them 60-100 days after weaning.

• “First service-to-repeat-service interval” is the time it takes to find recycling females after breeding. Top farms will find over 60% of regular returns to heat by Day 25 after mating. In some herds, often after a porcine reproductive and respiratory syndrome (PRRS) break, this figure will rise as high as 81 days. Your breeding crew is responsible for finding those open females.

• The number of sows bred three times or more will also add an extra day to your average.

• “Wean-to-removal” is determined by how you handle your culls after weaning and can add several days to “non-productive days.” Some farms remove cull females the day of weaning, while others hold them until they have a truckload. Some farms remove cull sows on a standard schedule.

• “Death loss” also contributes to non-productive days. The female that dies at 113 days of gestation registers 113 non-productive days. As you can see, there are several areas that can affect the number of “mated female non-productive days.” Your management team can improve this measure by identifying recycling sows sooner, reducing female deaths, working to get weaned females to cycle sooner, and by tracking non-cycling weaned females or culling repeat females after two services.

If you reduce your “mated female non-productive days” from an average of 41 days to 31 days and you have a breakeven cost of $34/pig, with 26 pigs weaned/mated female/year, your non-productive day cost would be $2.42/day. Decreasing “mated female non-productive days” will increase your “litters/mated female/year” and the “pigs weaned/mated female/year” by 3% and reduce your breakeven/weaned pig by $1/pig.

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