Using a Stochastic Model to Evaluate Swine Production Management with Paylean IV: Return of Accurate Sorting for Marketing

Purdue Universtiy 2003 Swine Research Report. Recently, many studies were conducted on value-based pig marketing and were aimed at reducing sort loss by the packers grid. One of the often-suggested solutions to reduce sort loss was to weigh each pig before marketing. Because weighing pigs by hand is practically too expensive, the solution is not feasible for most producers. Recently, however, the idea of weighing pigs before marketing has become possible because of an innovation to grow-finish barns, which is the Automatic Sorting Technology (AST). The primary improvement of AST barns is to equip the barns with one or more electronic scales, which can automatically weigh, record, and sort the weights of the animals when pigs pass through the scales to access food or water. The only labor input is to set a threshold weight in the scale; therefore, the cost is almost zero to perform the task of sorting pigs before marketing. In addition, the recorded weight gives the producer precise information on the growth performance of the group as a whole, which helps producers to make the correct decisions regarding the time to market the animals. Hence, accurate sorting and marketing timing can be realized by the AST barns, and with AST sorting, sort loss received from pigs outside the desired weight ranges supposedly would be reduced compared with traditional hand sorting. One of the goals of this research is to investigate the potential saving of sort loss through accurate sorting by the AST barn. With accurate sorting and marketing decisions, the optimal production management of dietary lysine and Paylean (ractopamine, RAC) may shift. Particularly, with the use of Paylean; the Paylean onset time, dietary lysine concentrations and marketing time require precise management to obtain the full potential benefit from the RAC feed additive. Therefore, the second aim of the research was to investigate the optimal production and marketing strategies of Paylean with the AST barn. Note that this research focuses only on assessing the savings of AST by accurate sorting, and it is not an economic evaluation of the AST barn. It was reported by other research that the AST barns have many potential benefits other than saving the sort loss (Conner and Lowe, 2002; Neutkens, 2002). Therefore, readers interested in the complete economic evaluation of the AST barn should refer to other research results as well.