Biological and economic implications of changing sow litter size: Informing on-farm management and decision making

David A Widmar, Purdue University

Abstract

Major structural changes have taken place in the swine industry over the last two decades, with fewer total producers responsible for producing increasing amounts of pork. Even seemingly minor swine production decisions today have huge economic impacts for producers. Producers must carefully evaluate changes within their system from both biological and economic perspectives. Stochastic bioeconomic modeling is needed to evaluate how a change in the production system affects each individual piglet's biological and economic performance. A stochastic bioeconomic model was used to evaluate biological and economic consequences of larger litter sizes, the biological and economic difference in the performance of light- and heavy birth weight piglets, alternative marketing strategies, and a management production strategy to standardize litter sizes after birth were evaluated. As mean litter size was increased from 8.5 to 22.5, increased profitability per head marketed was observed. When the mean litter size was incrementally increased from 22.5 to 24.5, a decrease in profitability was observed as it was no longer economically beneficial to increase the mean litter size. At larger litter sizes, a much larger portion of the pig population was comprised of light-birth weight piglets (birth weights less than 1kg). These light-birth weight piglets have slower biological growth rates and at mean litter sizes of 12.5, are expected to have negative profitability and only cover a portion of their allocated fixed cost. Two alternative market strategies were evaluated, day-marketing and weight-marketing. The weight-market system marketed the first two market cuts before the day-market system, and after the day-market system for the third cut. The earlier marketing of hogs under the weight-market system resulted in less revenue per head marketed, a result of light slaughter weights from being on feed fewer days. The saving in feed costs, from being on feed fewer days, did not offset the reduction in revenue from lighter slaughter weights. Finally, biological and economic implications of standardizing litter sizes were evaluated. Compared to management's decision to not standardize litters, it was found that standardizing generated more value in smaller litter sizes (8.5), compared to larger litters (12.5 and 16.5) under the assumptions of the models employed in this analysis.

Degree

M.S.

Advisors

Olynk, Purdue University.

Subject Area

Animal sciences|Agricultural economics

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