Trout Production Following Prawns

Trout production can be accomplished in most parts of Georgia, during the winter months if the water temperature and dissolved oxygen are measured routinely and maintained in the range of tolerance of the rainbow trout. Temperature optima are between 55 and 65 ^oF (13 to 18 ^oC) for rainbow trout. Winter water temperatures, at Tifton, average about 61 ^oF (16 ^o) between November and March. Winter water temperatures at locations north of Tifton are expected to be cooler, extending the growing season for trout. The minimum temperature for rainbow trout growth is 38 ^oF (4 ^oC) and feed should be limited when water temperatures are between 38 and 55 ^oF (4 and 13 ^oC).

Stocking density of trout should not exceed 3,000 per acre. A 1/4 pound trout (about 9 inches long) should be stocked in November. After 4 to 4.5 months, the trout should be greater than ½ pound average weight. Feed a good quality trout feed of 38 to 40 percent protein. Do not exceed 30 pounds of feed per acre per day in order to preserve good water quality and avoid the use of emergency aeration.

Dissolved oxygen concentration should be measured twice each day in order to plan aeration activity and guard against low dissolved oxygen. A minimum of 4 ppm dissolved oxygen should be maintained.

Harvest the trout with a seine or trap net before water temperatures exceed 65 degrees. Water temperature should be taken in the morning and evening at approximately 18 inches deep. The average temperature each day should be used to determine harvest timing.

Rainbow trout stockers may cost between $1.50 and $1.60 per pound. Therefore a relatively large investment is made to stock an acre of water. Survival of these large trout is expected to be very good if proper water quality is maintained and should average 95%. Selling price should take into account that approximately $ .80/lb is needed to cover the cost of the stocker trout. Trout feed may cost $400 to $500 per ton. Feed conversion will be very good and 1.4 pounds of feed per pound of trout weight gain is to be expected. Therefore $ .25/lb will be spent on feed costs to produce trout with an average weight of ½ pound.