Should Catfish
in Ponds
be Fed Over Winter?

 Tom Lovell and M.K. Kim

When water temperature drops below about 68°F, channel catfish don't gain weight economically; therefore, winter feeding is expensive and inconvenient. Conventional wisdom has advocated feeding catfish through winter months to keep the fish healthy and prevent weight loss. The return on investment from winter feeding is difficult to identify because of a lack of data on weight changes and feed efficiency with various feeding schedules. An AAES study suggests that partial winter feeding—where the fish are not fed during December, January and February—will yield fish of almost equal harvest size in the spring as continuous feeding throughout the winter.

The study was designed at the AAES to evaluate effects of three winter management regimens with two sizes (fingerlings and harvestable size) of catfish on weight change over winter and rate of gain by the fish the following grow-out season. The two sizes were stocked separately in earthen ponds on Nov. 1, 1995, and managed until April 23, 1996, on three feeding regimes: (1) no feeding; (2) restricted feeding, which meant no feeding during the months of December, January, and February; and (3) continuous feeding by a prescribed winter feeding schedule based on water temperature.

The fish were removed from the ponds the following spring and weight change, feed conversion, body composition, and processing yield were determined. Subsequently, fish from each of the over-winter treatments were placed back into the ponds and fed for the following six-month growing season to determine effects of the previous over-winter management scheme on fish performance during the next grow-out period.

The large fish on restricted feeding increased their weight by 41% over winter (Table 1), which was only slightly less than that of the continuously-fed large fish (48% increase). The large fish without winter feed lost 10% of their initial weight. The relative weight changes for the small fish showed a similar trend. Feed conversions were 1.6 for fish on restricted feeding and over 2.0 for continuously-fed fish in both size groups. Dressing yield for the food-size fish was not different between the fed groups, but was significantly lower for the non-fed fish. There were no significant losses to disease in any of the treatments.

At the end of the subsequent grow-out season, the large fish overwintered under the restricted feeding regime were slightly larger than those that had been continuously fed; the fish not fed during winter gained faster but did not quite reach the harvest weight of the other fish (Table 2). The smaller fish showed essentially the same responses as the large fish in relative weight changes. Feed conversions and dressing yields were not statistically different among treatments within both size groups.

These results indicate that a partial winter feeding program, where channel catfish are not fed during December, January, and February, will yield fish of almost equal harvest size at the end of winter and at the end of the next grow-out period as full-feeding over winter in Alabama. Fish not fed for a six-month winter period will lose 8 to 10% of weight during winter; however the fish will grow faster during the following grow-out season and will reach a harvest weight only slightly less than that of winter-fed fish.

Lovell is a Distinguished University Professor and Kim is a former Doctoral Graduate Research Assistant of Fisheries and Allied Aquacultures.