Sow Longevity – Its Improvement and Economic Importance Ken Stalder Department of Animal Science Iowa State University

Replacement Culling Avg. Parity Death Rate, % Rate,% At Culling Loss, % PigCHAMP Pigtales Not Reported Reported Averages

Worldwide Replacement Rates Australian average 63.8% replacement from 1992 through 2002 Brazil 2002 averaged 55% replacement rate, 43% culling rate, 5.5% death loss, and average parity of culled sows of Canada 2002 averaged 58% replacement rate, 39.5% culling rate, 6.5% death loss, and average parity of culled sows of Japan 2000 averaged 47.6% replacement rate, 28.6% culling rate, 5.3% death loss, and average parity of culled sows of 3.8.

How Do Top Herds Perform? 2002 PigCHAMP data Upper 10 Percentile Replacement rate 32.7% Culling rate 22% Death Loss 2.8% Average parity at culling 5.5 Koketsu et al. (1999) A cohort of females born in 1990 Average lifetime pig production 67.2 pigs Average parity at removal was 5.6 parities

Why should we be concerned with longevity? Performance differences Number born alive Litter weaning weight Grow – Finish Performance Better protection from disease?? Introduction of more gilts Associated costs Welfare issue

Reasons For Culling Reproductive failure Old age Performance Feet and leg problems Death Post-farrowing problems 3 -5 Other Reason Percentage Culled

Cost of Replacing a Sow Replacement gilt Facility, feed, and labor during isolation and acclimation Vaccination and other veterinary expenses Disease risk Opportunity cost (interest rate) Performance difference between a gilt and mature sow.

Ideal Parity Distribution

Impact of Distribution on Productivity Average parity of sow herd 3.6 (industry) and 3.86 (book)

National Swine Improvement Federation Parity adjustment factors for number born alive ParityNumber born alive

National Swine Improvement Federation Parity adjustment factors for 21-day Litter Weight Parity21-day Litter Weight Adj

Given 10.2 pigs born alive from an average parity of sows farrowed of 3.5 Maximum Parity Number Born Alive Number Born Alive Per 100 Sows Value of Pigs $30 / pig Value Per Year, $ Difference from Maximum, $ / Year $29,370$1,527,240$87, $30,150$1,567,800$46, $30,630$1,592,760$21, $30,930$1,608,360$6, $31,050$1,614,600$ $31,050$1,614,600$ $30,990$1,611,480$3,120

Ideal Distribution Given Maximum Parity Culling per parity at 15% or 35% per year

Take Home Point: Economic Importance of Sow Longevity Reduced sow longevity (parity of sow at culling) results in fewer litters in which a sow has an opportunity to be sufficiently productive in order for her purchase to be profitable. Because of the cost of replacement females and short herd life, commercial swine producers should economically evaluate their replacement breeding herd decisions.

How do you evaluate how long a sow needs to remain in the breeding herd to be a profitable investment?

Income Fixed and variable costs Operation specific financial information Herd specific production data Development of the Sow Longevity Calculator Farrow-to-Finish and Breed-to-Wean custom spreadsheets available Uses Net Present Value analysis Version 2.0 Now Available Producer supplies

Data Entry Sheet

Feed Data Entry

Adjusting for Parity Performance Differences

Parity Adjustment Caution Only make these adjustments if you are extremely confident in the production numbers by parity. Do not adjust if values from your herd are based on small numbers Within a parity Across all parities

What does all of this get you? Net Present Value Analysis What does the NPV number mean? > 0 means the investment is profitable in the long term. < 0 means the investment will lose money in the long term.

Sensitivity Analyses – Gilt Purchase Price (F-F)

Sensitivity Analyses – Born Alive Number

Sensitivity Analyses – Hog Price Market

Sensitivity Analyses – Per Market Hog Feed Costs

Take Home Points: Factors Influencing Net Present Value of a Breeding Herd Replacement Female Major Factors Pigs produced (number born alive, mortalities at all levels, and substandard pigs at marketing) ± ½ pig changes parity at which positive NPV is reached 5% change in number born alive Price received for pigs marketed ± 2$ - 4$ changes parity at which positive NPV is reached 4.5% to 9% change in price Feed costs (feed efficiency and ingredient cost) ± 3$ per head changes parity at which positive NPV is reached 4.8% change in feed costs Take Home Points

Take Home Points: Factors Influencing Net Present Value of a Breeding Herd Replacement Female Relatively Minor Factors Replacement Gilt Cost ± 50$ change in gilt price required to change parity at which positive NPV is reached 25% change in number born alive Interest Rate Operation Equity Cull Animal Market Price

Factors Influencing Sow Longevity Factors under some genetic control Backfat of gilt at selection effects sow longevity Host of management effects feed intake, lactation length, gestation housing, etc.

Summary Improved longevity can increase profitability Focus on management practices that improve longevity More sows should be culled because of poor performance rather than reproductive reasons.

Those Interested in The Spreadsheet Spreadsheet designed to evaluate the investment in a replacement gilt available at: Iowa Pork Industry Center Iowa Pork Industry Center Web Site: Porkline (Iowa Only) me at

Thank You for Your Time and Attention Are there any questions?