Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 16, 2005
Publication Date: March 1, 2006
Citation: Wiese, N., Engle, C., Trimpey, J., Quagrainie, K., Green, B.W. 2006. Reducing catfish farm losses due to dockages assessed by processing plants. Journal of the World Aquaculture Society. 37:60-73.
Interpretive Summary: Not required.
Dockages can have a significant effect on catfish, Ictalurus punctatus, farm revenues. This study was conducted to quantify common dockages, examine seasonal and yearly variations in dockages assessed, and determine optimal production practices given various dockage scenarios. A convenience survey of invoice records from 30 commercial catfish farms and ten processing plants provided 3,686 daily catfish load records that were used to quantify dockages. A linear programming model was developed to examine optimal production practices given 11 alternative production scenarios with five size grading technologies subject to 24 types and levels of dockages. The survey revealed that 95% of catfish loads delivered to processing plants between 1997-2002 were assessed dockages that resulted in average losses of 2.45% per load or $0.066/kg of catfish marketed over the study period. Out-of-size discounts constituted the greatest losses. Dockage losses can be reduced by shifting either to longer-term single-batch production or more intensive grading. Longer-term production results in fewer smaller fish that would incur dockage losses. However, cash flow constraints require more intensive early-season grading. The grader choice depended on the dockage tolerance level and rate, the frequency distribution of sizes of catfish in the population, the efficiency of the grading technology, and the cost of the grading method. Larger farms minimize losses with intensive active grading (UAPB grader).