Strategies to Optimize Sow Longevity

Project: Strategies to optimize sow longevity

Agency: National Pork Board

PI: Rodriguez-Zas, Sandra.

Grant Number:



The objective is to address the US pork industry concerns about the deteriorating sow longevity statistics. Longevity is the result of a complex interplay of involuntary and voluntary culling practices, genetics, environmental and financial factors. The central hypothesis is that different combination of factors will result in optimal longevity under different management and financial contexts. The rationale is that these factors must be studied simultaneously to identify the optimal longevity structures within different contexts. To accomplish this, the specific aims are: a) to identify the factors influencing sow longevity while accounting for removal reason using survival analysis, and b) to compare alternative practices to optimize sow longevity using financial indicators. Complementary indicators of sow longevity and lifetime performance will be computed based on records from more than 108,000 sows in 37 herds. Survival analysis will include environmental and genetic factors and voluntary and involuntary removal reasons. The results will be incorporated into a Net Present Value and Return on Equity models to identify optimal scenarios. Estimates of the influence of sow longevity on profitability and of the impact of the different culling reasons will be used to develop strategies that optimize sow longevity under different management and economical contexts. The outcome will be a set of strategies based on sound statistical and economic analyzes that the producers can utilize to optimize sow longevity, lifetime production efficiency and animal well-being. The findings will have a vertical impact since preventive and reparatory guidelines will be communicated to the different constituents (e.g. breeding companies, producers) of the pork industry enhancing production efficiency and animal welfare.


Rodriguez-Zas, S. L., B. R. Southey, R. V. Knox, J. F. Connor, J. F. Lowe, and B. J. Roskamp. 2003. Bio-economic evaluation of sow longevity and profitability. Journal of Animal Science, 2003 Dec;81(12):2915-22.