OPTIMIZING CATFISH FEEDING AND STOCKING STRATEGIES OVER A TWO-YEAR PLANNING HORIZON

Abstract

Rising costs of feed ingredients in recent years have resulted in record increases in catfish feed prices. Since understocked channel catfish (Ictalurus punctatus) do not reach market size until the second year of production, static one-year economic models and analyses may not be adequate. A previous mixed-integer profit-maximizing model was extended to include a second year to evaluate the effects of varying feeding frequencies on farm management decisions, particularly on adjustments in the second year. Production options considered included frequency of feeding (every day, every other day, and every third day), multiple-batch production from four different fingerling sizes, and single-batch production from three different stocker sizes. Every day feeding was identified as the profit-maximizing feeding strategy on farms using multiple-batch production but unfavorable market prices, high feed prices, and operating capital constraints reduced feeding frequencies. Every day feeding remained the optimal strategy for farms in single-batch foodfish production. Market and capital constraints reduced the scale of farms operating in single-batch foodfish production, but did not change the optimal every day feeding strategy. Farms maximized profits by transitioning from multiple batch to single batch over the two-year period.

Keywords:

• channel catfish
• feeding frequency
• mixed-integer multi-year programming

ACKNOWLEDGMENTS

The authors thank Dr. Nathan Stone, Dr. Madan Dey, and Justin Grimm-Greenblatt for providing useful comments on an earlier version of this manuscript.

Notes

Notes: FF = food fish production from fingerlings; FP_r = fingerling purchase; Feed = feed consumed; S = sales of foodfish; Fry = fry purchased; F = fingerlings production; CMB = cleaning a pond from multiple-batch; FFS = foodfish from stockers; FP_r = fingerling purchase; FI = fingerling inventory; COI = carryover inventory; X = input, Y = output; P = market price for fish ; F_x = feed price; I_f = fingerling inventory price; I_s = stocker inventory price; Z_max = optimal maximized profit; total ponds = 43; pond size = 4–ha.

*Stocker class 51–114 g did not reach market size at the end of Year 1 when fed every third day.

Feed price = $440/MT; farm-gate price = $2.76/kg.

Ponds in each available capital category with the same superscript are the same ponds, which are carried over to the respective stocking and feeding strategies in Year 2.

Numbers in the table denote the number of ponds allocated for specific production activities. Foodfish production activities were stocked @ 11,250/ha. Medium-sized stocker = 115 g to 225 g; Large-sized stockers = 226 g to 400 g. On-farm production of large sized stockers is from 12.5 cm fingerlings stocked @ 100,000/ha. No on-farm production of fingerlings.

^a Number of ponds stocked in higher density (15,000/ha). Numbers denotes ponds allocated for production activities. Medium-sized stocker = 115 g to 225 g; Large-sized stockers = 226 g to 400 g.

Numbers denotes ponds allocated for production activities. Medium sized stocker = 115 g to 225 g; Large sized stockers = 226 g to 400 g.

*One of the stocker ponds produces small stockers to be used in Year 2.

†Two of the stocker pond produces medium stockers to be used in Year 2.

There was no understocking in Year 2 with ponds being stocked @ 11,250/ha density using medium-sized stockers on all farms to be raised in single-batch.