The Opportunity Cost of Utilizing Farrowing Room Space as Late-Term Gestation

The wean-to-farrow interval is comprised of two stochastic periods, the wean-to-service interval and gestation length. Variation in the wean-to-farrow interval can be affected by many biological factors as well as by management strategies like induced farrowing, multiple weanings/week and products which facilitate single, fixed-time AI like OvuGel®. The opportunity cost consequence of variation in a sow group’s wean-to-farrow interval is the inefficient use of limited farrowing house occupancy resulting in a lower average wean age. Uncertainty regarding an individual’s wean-to-farrow interval as well as variation of the interval among animals in the group results in a significant amount of farrowing house occupancy used for late gestation vs. farrowing or lactation. Increasing average wean age beyond threshold levels has been associated with increased wean-to-finish profitability as well as enhanced subsequent sow productivity especially for low parity sows.

A stochastic, bio-economic simulation model of the components of the wean-to-farrow interval was created adhering to management rules recommended by modern published standards. The model measures farrowing house occupancy efficiency under different management practices. We utilize up to 440,000 qualified, individual sow records from a large North American data base to estimate distributions by parity (and their correlation) for wean-to-service interval and gestation length. Analogous to non-productive sow days, we estimate for three management scenarios, the percent of available farrowing house days not spent either farrowing or lactating and their impact on average wean age and its standard deviation (STD) as measures of opportunity cost.

Scenario 1: Conventional breeding, single wean/one room; 19.52% farrowing house occupancy as late term gestation. Mean wean age: 18.73 days, STD: 1.74.

Scenario2: Conventional breeding, two weaning/week; two rooms, 15.23% farrowing house occupancy as late term gestation. Mean wean age: 19.89 days, STD: 1.39.

Scenario3: OvuGel®, single, fixed-time AI day five post-weaning, induction day 115 for all animals not yet farrowed; 11.79% total farrowing house occupancy days as late term gestation, Mean wean age: 20.82 days, STD: 0.76

Use of OvuGel® and single fixed time AI, which facilitated induction at day 115 of gestation, added mean 2.09 days to average wean age while reducing its standard deviation by almost a full day compared to a single wean batch system. The percent of farrowing house occupancy used for late gestation was reduced by 39.6 percent.

Disclosure of Interest: D. DiPietre Conflict with: Consultant to JBS United, L. Mulberry Conflict with: Consultant to JBS United, D. Dau Conflict with: JBS United Animal Health, C. Francisco Conflict with: JBS United Animal Health.